diff --git a/CHANGES.md b/CHANGES.md
index d2d1902205..654f2e4fa4 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -48,6 +48,7 @@ Changes in RiotX 0.9.0 (2019-12-05)
 Features ✨:
  - Account creation. It's now possible to create account on any homeserver with RiotX (#34)
  - Iteration of the login flow (#613)
+ - [SDK] MSC2241 / verification in DMs (#707)
 
 Improvements 🙌:
  - Send mention Pills from composer
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationService.kt
index 88c0787b4d..902baae06f 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationService.kt
@@ -16,19 +16,42 @@
 
 package im.vector.matrix.android.api.session.crypto.sas
 
+import im.vector.matrix.android.api.MatrixCallback
+
+/**
+ * https://matrix.org/docs/spec/client_server/r0.5.0#key-verification-framework
+ *
+ * Verifying keys manually by reading out the Ed25519 key is not very user friendly, and can lead to errors.
+ * SAS verification is a user-friendly key verification process.
+ * SAS verification is intended to be a highly interactive process for users,
+ * and as such exposes verification methods which are easier for users to use.
+ */
 interface SasVerificationService {
+
     fun addListener(listener: SasVerificationListener)
 
     fun removeListener(listener: SasVerificationListener)
 
+    /**
+     * Mark this device as verified manually
+     */
     fun markedLocallyAsManuallyVerified(userId: String, deviceID: String)
 
     fun getExistingTransaction(otherUser: String, tid: String): SasVerificationTransaction?
 
+    /**
+     * Shortcut for KeyVerificationStart.VERIF_METHOD_SAS
+     * @see beginKeyVerification
+     */
     fun beginKeyVerificationSAS(userId: String, deviceID: String): String?
 
+    /**
+     * Request a key verification from another user using toDevice events.
+     */
     fun beginKeyVerification(method: String, userId: String, deviceID: String): String?
 
+    fun requestKeyVerificationInDMs(userId: String, roomId: String, callback: MatrixCallback<String>?)
+
     // fun transactionUpdated(tx: SasVerificationTransaction)
 
     interface SasVerificationListener {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt
index d24ccadb55..9610daf294 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/crypto/sas/SasVerificationTransaction.kt
@@ -17,7 +17,7 @@
 package im.vector.matrix.android.api.session.crypto.sas
 
 interface SasVerificationTransaction {
-    val state: SasVerificationTxState
+    var state: SasVerificationTxState
 
     val cancelledReason: CancelCode?
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/EventType.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/EventType.kt
index 38c24fa89b..a8c6aed44e 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/EventType.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/EventType.kt
@@ -72,6 +72,7 @@ object EventType {
     const val KEY_VERIFICATION_KEY = "m.key.verification.key"
     const val KEY_VERIFICATION_MAC = "m.key.verification.mac"
     const val KEY_VERIFICATION_CANCEL = "m.key.verification.cancel"
+    const val KEY_VERIFICATION_DONE = "m.key.verification.done"
 
     // Relation Events
     const val REACTION = "m.reaction"
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageRelationContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageRelationContent.kt
new file mode 100644
index 0000000000..ec773916fd
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageRelationContent.kt
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+
+@JsonClass(generateAdapter = true)
+internal data class MessageRelationContent(
+        @Json(name = "m.relates_to") val relatesTo: RelationDefaultContent?
+)
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageType.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageType.kt
index 8cef40f21a..d4e6d5ea71 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageType.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageType.kt
@@ -26,6 +26,7 @@ object MessageType {
     const val MSGTYPE_VIDEO = "m.video"
     const val MSGTYPE_LOCATION = "m.location"
     const val MSGTYPE_FILE = "m.file"
+    const val MSGTYPE_VERIFICATION_REQUEST = "m.key.verification.request"
     const val FORMAT_MATRIX_HTML = "org.matrix.custom.html"
     // Add, in local, a fake message type in order to StickerMessage can inherit Message class
     // Because sticker isn't a message type but a event type without msgtype field
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationAcceptContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationAcceptContent.kt
new file mode 100644
index 0000000000..bda4b9f0ac
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationAcceptContent.kt
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.events.model.RelationType
+import im.vector.matrix.android.api.session.events.model.toContent
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+import im.vector.matrix.android.internal.crypto.verification.AcceptVerifInfoFactory
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoAccept
+import timber.log.Timber
+
+@JsonClass(generateAdapter = true)
+internal data class MessageVerificationAcceptContent(
+        @Json(name = "hash") override val hash: String?,
+        @Json(name = "key_agreement_protocol") override val keyAgreementProtocol: String?,
+        @Json(name = "message_authentication_code") override val messageAuthenticationCode: String?,
+        @Json(name = "short_authentication_string") override val shortAuthenticationStrings: List<String>?,
+        @Json(name = "m.relates_to") val relatesTo: RelationDefaultContent?,
+        @Json(name = "commitment") override var commitment: String? = null
+) : VerifInfoAccept {
+
+    override val transactionID: String?
+        get() = relatesTo?.eventId
+
+    override fun isValid(): Boolean {
+        if (transactionID.isNullOrBlank()
+                || keyAgreementProtocol.isNullOrBlank()
+                || hash.isNullOrBlank()
+                || commitment.isNullOrBlank()
+                || messageAuthenticationCode.isNullOrBlank()
+                || shortAuthenticationStrings.isNullOrEmpty()) {
+            Timber.e("## received invalid verification request")
+            return false
+        }
+        return true
+    }
+
+    override fun toEventContent() = this.toContent()
+
+    companion object : AcceptVerifInfoFactory {
+
+        override fun create(tid: String,
+                            keyAgreementProtocol: String,
+                            hash: String,
+                            commitment: String,
+                            messageAuthenticationCode: String,
+                            shortAuthenticationStrings: List<String>): VerifInfoAccept {
+            return MessageVerificationAcceptContent(
+                    hash,
+                    keyAgreementProtocol,
+                    messageAuthenticationCode,
+                    shortAuthenticationStrings,
+                    RelationDefaultContent(
+                            RelationType.REFERENCE,
+                            tid
+                    ),
+                    commitment
+            )
+        }
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationCancelContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationCancelContent.kt
new file mode 100644
index 0000000000..08fc3cbdbb
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationCancelContent.kt
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.crypto.sas.CancelCode
+import im.vector.matrix.android.api.session.events.model.RelationType
+import im.vector.matrix.android.api.session.events.model.toContent
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoCancel
+
+@JsonClass(generateAdapter = true)
+internal data class MessageVerificationCancelContent(
+        @Json(name = "code") override val code: String? = null,
+        @Json(name = "reason") override val reason: String? = null,
+        @Json(name = "m.relates_to") val relatesTo: RelationDefaultContent?
+
+) : VerifInfoCancel {
+
+    override val transactionID: String?
+        get() = relatesTo?.eventId
+
+    override fun toEventContent() = this.toContent()
+
+    override fun isValid(): Boolean {
+        if (transactionID.isNullOrBlank() || code.isNullOrBlank()) {
+            return false
+        }
+        return true
+    }
+
+    companion object {
+        fun create(transactionId: String, reason: CancelCode): MessageVerificationCancelContent {
+            return MessageVerificationCancelContent(
+                    reason.value,
+                    reason.humanReadable,
+                    RelationDefaultContent(
+                            RelationType.REFERENCE,
+                            transactionId
+                    )
+            )
+        }
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationDoneContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationDoneContent.kt
new file mode 100644
index 0000000000..965fcb79bb
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationDoneContent.kt
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+import im.vector.matrix.android.internal.crypto.verification.VerificationInfo
+
+@JsonClass(generateAdapter = true)
+internal data class MessageVerificationDoneContent(
+        @Json(name = "m.relates_to") val relatesTo: RelationDefaultContent?
+) : VerificationInfo {
+    override fun isValid() = true
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationKeyContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationKeyContent.kt
new file mode 100644
index 0000000000..0b93e3299a
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationKeyContent.kt
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.events.model.RelationType
+import im.vector.matrix.android.api.session.events.model.toContent
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoKey
+import im.vector.matrix.android.internal.crypto.verification.KeyVerifInfoFactory
+import timber.log.Timber
+
+@JsonClass(generateAdapter = true)
+internal data class MessageVerificationKeyContent(
+        /**
+         * The device’s ephemeral public key, as an unpadded base64 string
+         */
+        @Json(name = "key") override val key: String? = null,
+        @Json(name = "m.relates_to") val relatesTo: RelationDefaultContent?
+) : VerifInfoKey {
+
+    override val transactionID: String?
+        get() = relatesTo?.eventId
+
+    override fun isValid(): Boolean {
+        if (transactionID.isNullOrBlank() || key.isNullOrBlank()) {
+            Timber.e("## received invalid verification request")
+            return false
+        }
+        return true
+    }
+
+    override fun toEventContent() = this.toContent()
+
+    companion object : KeyVerifInfoFactory {
+
+        override fun create(tid: String, pubKey: String): VerifInfoKey {
+            return MessageVerificationKeyContent(
+                    pubKey,
+                    RelationDefaultContent(
+                            RelationType.REFERENCE,
+                            tid
+                    )
+            )
+        }
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationMacContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationMacContent.kt
new file mode 100644
index 0000000000..92ea4bca52
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationMacContent.kt
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.events.model.RelationType
+import im.vector.matrix.android.api.session.events.model.toContent
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoMac
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoMacFactory
+
+@JsonClass(generateAdapter = true)
+internal data class MessageVerificationMacContent(
+        @Json(name = "mac") override val mac: Map<String, String>? = null,
+        @Json(name = "keys") override val keys: String? = null,
+        @Json(name = "m.relates_to") val relatesTo: RelationDefaultContent?
+) : VerifInfoMac {
+
+    override val transactionID: String?
+        get() = relatesTo?.eventId
+
+    override fun toEventContent() = this.toContent()
+
+    override fun isValid(): Boolean {
+        if (transactionID.isNullOrBlank() || keys.isNullOrBlank() || mac.isNullOrEmpty()) {
+            return false
+        }
+        return true
+    }
+
+    companion object : VerifInfoMacFactory {
+        override fun create(tid: String, mac: Map<String, String>, keys: String): VerifInfoMac {
+            return MessageVerificationMacContent(
+                    mac,
+                    keys,
+                    RelationDefaultContent(
+                            RelationType.REFERENCE,
+                            tid
+                    )
+            )
+        }
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationRequestContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationRequestContent.kt
new file mode 100644
index 0000000000..afefa39847
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationRequestContent.kt
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.events.model.Content
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+
+@JsonClass(generateAdapter = true)
+class MessageVerificationRequestContent(
+        @Json(name = "msgtype") override val type: String = MessageType.MSGTYPE_VERIFICATION_REQUEST,
+        @Json(name = "body") override val body: String,
+        @Json(name = "from_device") val fromDevice: String,
+        @Json(name = "methods") val methods: List<String>,
+        @Json(name = "to") val to: String,
+        // @Json(name = "timestamp") val timestamp: Int,
+        @Json(name = "format") val format: String? = null,
+        @Json(name = "formatted_body") val formattedBody: String? = null,
+        @Json(name = "m.relates_to") override val relatesTo: RelationDefaultContent? = null,
+        @Json(name = "m.new_content") override val newContent: Content? = null
+) : MessageContent
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationStartContent.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationStartContent.kt
new file mode 100644
index 0000000000..f6ec00ffb2
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/message/MessageVerificationStartContent.kt
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.api.session.room.model.message
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.api.session.crypto.sas.SasMode
+import im.vector.matrix.android.api.session.events.model.toContent
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationStart
+import im.vector.matrix.android.internal.crypto.verification.SASVerificationTransaction
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoStart
+import im.vector.matrix.android.internal.util.JsonCanonicalizer
+import timber.log.Timber
+
+@JsonClass(generateAdapter = true)
+data class MessageVerificationStartContent(
+        @Json(name = "from_device") override val fromDevice: String?,
+        @Json(name = "hashes") override val hashes: List<String>?,
+        @Json(name = "key_agreement_protocols") override val keyAgreementProtocols: List<String>?,
+        @Json(name = "message_authentication_codes") override val messageAuthenticationCodes: List<String>?,
+        @Json(name = "short_authentication_string") override val shortAuthenticationStrings: List<String>?,
+        @Json(name = "method") override val method: String?,
+        @Json(name = "m.relates_to") val relatesTo: RelationDefaultContent?
+) : VerifInfoStart {
+
+    override fun toCanonicalJson(): String? {
+       return JsonCanonicalizer.getCanonicalJson(MessageVerificationStartContent::class.java, this)
+    }
+
+    override val transactionID: String?
+        get() = relatesTo?.eventId
+
+    override fun isValid(): Boolean {
+        if (
+                (transactionID.isNullOrBlank() || fromDevice.isNullOrBlank() || method != KeyVerificationStart.VERIF_METHOD_SAS || keyAgreementProtocols.isNullOrEmpty() || hashes.isNullOrEmpty())
+                || !hashes.contains("sha256") || messageAuthenticationCodes.isNullOrEmpty()
+                || (!messageAuthenticationCodes.contains(SASVerificationTransaction.SAS_MAC_SHA256) && !messageAuthenticationCodes.contains(SASVerificationTransaction.SAS_MAC_SHA256_LONGKDF))
+                || shortAuthenticationStrings.isNullOrEmpty()
+                || !shortAuthenticationStrings.contains(SasMode.DECIMAL)) {
+            Timber.e("## received invalid verification request")
+            return false
+        }
+        return true
+    }
+
+    override fun toEventContent()  = this.toContent()
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/CryptoModule.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/CryptoModule.kt
index a12f6e40ce..4243c6a464 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/CryptoModule.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/CryptoModule.kt
@@ -177,6 +177,9 @@ internal abstract class CryptoModule {
     @Binds
     abstract fun bindSendToDeviceTask(sendToDeviceTask: DefaultSendToDeviceTask): SendToDeviceTask
 
+    @Binds
+    abstract fun bindEncryptEventTask(encryptEventTask: DefaultEncryptEventTask): EncryptEventTask
+
     @Binds
     abstract fun bindClaimOneTimeKeysForUsersDeviceTask(claimOneTimeKeysForUsersDevice: DefaultClaimOneTimeKeysForUsersDevice)
             : ClaimOneTimeKeysForUsersDeviceTask
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/DefaultCryptoService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/DefaultCryptoService.kt
index c50b9e2e10..58ab8dda32 100755
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/DefaultCryptoService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/DefaultCryptoService.kt
@@ -136,6 +136,10 @@ internal class DefaultCryptoService @Inject constructor(
         private val cryptoCoroutineScope: CoroutineScope
 ) : CryptoService {
 
+    init {
+        sasVerificationService.cryptoService = this
+    }
+
     private val uiHandler = Handler(Looper.getMainLooper())
 
     // MXEncrypting instance for each room.
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationAccept.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationAccept.kt
index 7be6f2042c..20d7682cb9 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationAccept.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationAccept.kt
@@ -17,13 +17,15 @@ package im.vector.matrix.android.internal.crypto.model.rest
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoAccept
+import im.vector.matrix.android.internal.crypto.verification.AcceptVerifInfoFactory
 import timber.log.Timber
 
 /**
  * Sent by Bob to accept a verification from a previously sent m.key.verification.start message.
  */
 @JsonClass(generateAdapter = true)
-data class KeyVerificationAccept(
+internal data class KeyVerificationAccept(
 
         /**
          * string to identify the transaction.
@@ -31,39 +33,41 @@ data class KeyVerificationAccept(
          * Alice’s device should record this ID and use it in future messages in this transaction.
          */
         @Json(name = "transaction_id")
-        var transactionID: String? = null,
+        override var transactionID: String? = null,
 
         /**
          * The key agreement protocol that Bob’s device has selected to use, out of the list proposed by Alice’s device
          */
         @Json(name = "key_agreement_protocol")
-        var keyAgreementProtocol: String? = null,
+        override var keyAgreementProtocol: String? = null,
 
         /**
          * The hash algorithm that Bob’s device has selected to use, out of the list proposed by Alice’s device
          */
-        var hash: String? = null,
+        @Json(name = "hash")
+        override var hash: String? = null,
 
         /**
          * The message authentication code that Bob’s device has selected to use, out of the list proposed by Alice’s device
          */
         @Json(name = "message_authentication_code")
-        var messageAuthenticationCode: String? = null,
+        override var messageAuthenticationCode: String? = null,
 
         /**
          * An array of short authentication string methods that Bob’s client (and Bob) understands.  Must be a subset of the list proposed by Alice’s device
          */
         @Json(name = "short_authentication_string")
-        var shortAuthenticationStrings: List<String>? = null,
+        override var shortAuthenticationStrings: List<String>? = null,
 
         /**
          * The hash (encoded as unpadded base64) of the concatenation of the device’s ephemeral public key (QB, encoded as unpadded base64)
          *  and the canonical JSON representation of the m.key.verification.start message.
          */
-        var commitment: String? = null
-) : SendToDeviceObject {
+        @Json(name = "commitment")
+        override var commitment: String? = null
+) : SendToDeviceObject, VerifInfoAccept {
 
-    fun isValid(): Boolean {
+    override fun isValid(): Boolean {
         if (transactionID.isNullOrBlank()
                 || keyAgreementProtocol.isNullOrBlank()
                 || hash.isNullOrBlank()
@@ -76,13 +80,15 @@ data class KeyVerificationAccept(
         return true
     }
 
-    companion object {
-        fun create(tid: String,
-                   keyAgreementProtocol: String,
-                   hash: String,
-                   commitment: String,
-                   messageAuthenticationCode: String,
-                   shortAuthenticationStrings: List<String>): KeyVerificationAccept {
+    override fun toSendToDeviceObject() = this
+
+    companion object : AcceptVerifInfoFactory {
+        override fun create(tid: String,
+                            keyAgreementProtocol: String,
+                            hash: String,
+                            commitment: String,
+                            messageAuthenticationCode: String,
+                            shortAuthenticationStrings: List<String>): VerifInfoAccept {
             return KeyVerificationAccept().apply {
                 this.transactionID = tid
                 this.keyAgreementProtocol = keyAgreementProtocol
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationCancel.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationCancel.kt
index b5c45e9566..7ffffbbfa1 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationCancel.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationCancel.kt
@@ -18,40 +18,43 @@ package im.vector.matrix.android.internal.crypto.model.rest
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
 import im.vector.matrix.android.api.session.crypto.sas.CancelCode
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoCancel
 
 /**
  * To device event sent by either party to cancel a key verification.
  */
 @JsonClass(generateAdapter = true)
-data class KeyVerificationCancel(
+internal data class KeyVerificationCancel(
         /**
          * the transaction ID of the verification to cancel
          */
         @Json(name = "transaction_id")
-        var transactionID: String? = null,
+        override val transactionID: String? = null,
 
         /**
          * machine-readable reason for cancelling, see #CancelCode
          */
-        var code: String? = null,
+        override var code: String? = null,
 
         /**
          * human-readable reason for cancelling.  This should only be used if the receiving client does not understand the code given.
          */
-        var reason: String? = null
-) : SendToDeviceObject {
+        override var reason: String? = null
+) : SendToDeviceObject, VerifInfoCancel {
 
     companion object {
         fun create(tid: String, cancelCode: CancelCode): KeyVerificationCancel {
-            return KeyVerificationCancel().apply {
-                this.transactionID = tid
-                this.code = cancelCode.value
-                this.reason = cancelCode.humanReadable
-            }
+            return KeyVerificationCancel(
+                    tid,
+                    cancelCode.value,
+                    cancelCode.humanReadable
+            )
         }
     }
 
-    fun isValid(): Boolean {
+    override fun toSendToDeviceObject() = this
+
+    override fun isValid(): Boolean {
         if (transactionID.isNullOrBlank() || code.isNullOrBlank()) {
             return false
         }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationKey.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationKey.kt
index 4c6243fee3..458c12743f 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationKey.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationKey.kt
@@ -17,37 +17,33 @@ package im.vector.matrix.android.internal.crypto.model.rest
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.internal.crypto.verification.KeyVerifInfoFactory
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoKey
 
 /**
  * Sent by both devices to send their ephemeral Curve25519 public key to the other device.
  */
 @JsonClass(generateAdapter = true)
-data class KeyVerificationKey(
+internal data class KeyVerificationKey(
         /**
          * the ID of the transaction that the message is part of
          */
-        @Json(name = "transaction_id")
-        @JvmField
-        var transactionID: String? = null,
+        @Json(name = "transaction_id") override var transactionID: String? = null,
 
         /**
          * The device’s ephemeral public key, as an unpadded base64 string
          */
-        @JvmField
-        var key: String? = null
+        @Json(name = "key") override val key: String? = null
 
-) : SendToDeviceObject {
+) : SendToDeviceObject, VerifInfoKey {
 
-    companion object {
-        fun create(tid: String, key: String): KeyVerificationKey {
-            return KeyVerificationKey().apply {
-                this.transactionID = tid
-                this.key = key
-            }
+    companion object : KeyVerifInfoFactory {
+        override fun create(tid: String, pubKey: String): KeyVerificationKey {
+            return KeyVerificationKey(tid, pubKey)
         }
     }
 
-    fun isValid(): Boolean {
+    override fun isValid(): Boolean {
         if (transactionID.isNullOrBlank() || key.isNullOrBlank()) {
             return false
         }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationMac.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationMac.kt
index 8732e366d2..d2c147e145 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationMac.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationMac.kt
@@ -17,49 +17,32 @@ package im.vector.matrix.android.internal.crypto.model.rest
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoMac
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoMacFactory
 
 /**
  * Sent by both devices to send the MAC of their device key to the other device.
  */
 @JsonClass(generateAdapter = true)
-data class KeyVerificationMac(
-        /**
-         * the ID of the transaction that the message is part of
-         */
-        @Json(name = "transaction_id")
-        var transactionID: String? = null,
+internal data class KeyVerificationMac(
+        @Json(name = "transaction_id") override val transactionID: String? = null,
+        @Json(name = "mac") override val mac: Map<String, String>? = null,
+        @Json(name = "key") override val keys: String? = null
 
-        /**
-         * A map of key ID to the MAC of the key, as an unpadded base64 string, calculated using the MAC key
-         */
-        @JvmField
-        var mac: Map<String, String>? = null,
+) : SendToDeviceObject, VerifInfoMac {
 
-        /**
-         *  The MAC of the comma-separated, sorted list of key IDs given in the mac property,
-         *  as an unpadded base64 string, calculated using the MAC key.
-         *  For example, if the mac property gives MACs for the keys ed25519:ABCDEFG and ed25519:HIJKLMN, then this property will
-         *  give the MAC of the string “ed25519:ABCDEFG,ed25519:HIJKLMN”.
-         */
-        @JvmField
-        var keys: String? = null
-
-) : SendToDeviceObject {
-
-    fun isValid(): Boolean {
+    override fun isValid(): Boolean {
         if (transactionID.isNullOrBlank() || keys.isNullOrBlank() || mac.isNullOrEmpty()) {
             return false
         }
         return true
     }
 
-    companion object {
-        fun create(tid: String, mac: Map<String, String>, keys: String): KeyVerificationMac {
-            return KeyVerificationMac().apply {
-                this.transactionID = tid
-                this.mac = mac
-                this.keys = keys
-            }
+    override fun toSendToDeviceObject(): SendToDeviceObject? = this
+
+    companion object : VerifInfoMacFactory {
+        override fun create(tid: String, mac: Map<String, String>, keys: String): VerifInfoMac {
+            return KeyVerificationMac(tid, mac, keys)
         }
     }
 }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationRequest.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationRequest.kt
new file mode 100644
index 0000000000..14954a17cd
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationRequest.kt
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.model.rest
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import im.vector.matrix.android.internal.crypto.verification.VerificationInfo
+
+/**
+ * Requests a key verification with another user's devices.
+ */
+@JsonClass(generateAdapter = true)
+data class KeyVerificationRequest(
+
+        @Json(name = "from_device")
+        val fromDevice: String,
+        /** The verification methods supported by the sender. */
+        val methods: List<String> = listOf(KeyVerificationStart.VERIF_METHOD_SAS),
+        /**
+         *  The POSIX timestamp in milliseconds for when the request was made.
+         *  If the request is in the future by more than 5 minutes or more than 10 minutes in the past,
+         *  the message should be ignored by the receiver.
+         */
+        val timestamp: Int,
+
+        @Json(name = "transaction_id")
+        var transactionID: String? = null
+
+) : SendToDeviceObject, VerificationInfo {
+
+    override fun isValid(): Boolean {
+        // TODO
+        return true
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationStart.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationStart.kt
index 081b19161a..f7cc10a12b 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationStart.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/rest/KeyVerificationStart.kt
@@ -19,21 +19,27 @@ import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
 import im.vector.matrix.android.api.session.crypto.sas.SasMode
 import im.vector.matrix.android.internal.crypto.verification.SASVerificationTransaction
+import im.vector.matrix.android.internal.crypto.verification.VerifInfoStart
+import im.vector.matrix.android.internal.util.JsonCanonicalizer
 import timber.log.Timber
 
 /**
  * Sent by Alice to initiate an interactive key verification.
  */
 @JsonClass(generateAdapter = true)
-class KeyVerificationStart : SendToDeviceObject {
+class KeyVerificationStart : SendToDeviceObject, VerifInfoStart {
+
+    override fun toCanonicalJson(): String? {
+        return JsonCanonicalizer.getCanonicalJson(KeyVerificationStart::class.java, this)
+    }
 
     /**
      * Alice’s device ID
      */
     @Json(name = "from_device")
-    var fromDevice: String? = null
+    override var fromDevice: String? = null
 
-    var method: String? = null
+    override var method: String? = null
 
     /**
      * String to identify the transaction.
@@ -41,7 +47,7 @@ class KeyVerificationStart : SendToDeviceObject {
      * Alice’s device should record this ID and use it in future messages in this transaction.
      */
     @Json(name = "transaction_id")
-    var transactionID: String? = null
+    override var transactionID: String? = null
 
     /**
      * An array of key agreement protocols that Alice’s client understands.
@@ -49,13 +55,13 @@ class KeyVerificationStart : SendToDeviceObject {
      * Other methods may be defined in the future
      */
     @Json(name = "key_agreement_protocols")
-    var keyAgreementProtocols: List<String>? = null
+    override var keyAgreementProtocols: List<String>? = null
 
     /**
      * An array of hashes that Alice’s client understands.
      * Must include “sha256”.  Other methods may be defined in the future.
      */
-    var hashes: List<String>? = null
+    override var hashes: List<String>? = null
 
     /**
      * An array of message authentication codes that Alice’s client understands.
@@ -63,7 +69,7 @@ class KeyVerificationStart : SendToDeviceObject {
      * Other methods may be defined in the future.
      */
     @Json(name = "message_authentication_codes")
-    var messageAuthenticationCodes: List<String>? = null
+    override var messageAuthenticationCodes: List<String>? = null
 
     /**
      * An array of short authentication string methods that Alice’s client (and Alice) understands.
@@ -72,13 +78,13 @@ class KeyVerificationStart : SendToDeviceObject {
      * Other methods may be defined in the future
      */
     @Json(name = "short_authentication_string")
-    var shortAuthenticationStrings: List<String>? = null
+    override var shortAuthenticationStrings: List<String>? = null
 
     companion object {
         const val VERIF_METHOD_SAS = "m.sas.v1"
     }
 
-    fun isValid(): Boolean {
+    override fun isValid(): Boolean {
         if (transactionID.isNullOrBlank()
                 || fromDevice.isNullOrBlank()
                 || method != VERIF_METHOD_SAS
@@ -95,4 +101,6 @@ class KeyVerificationStart : SendToDeviceObject {
         }
         return true
     }
+
+    override fun toSendToDeviceObject() = this
 }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/EncryptEventTask.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/EncryptEventTask.kt
new file mode 100644
index 0000000000..951bc6385a
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/EncryptEventTask.kt
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.tasks
+
+import im.vector.matrix.android.api.session.crypto.CryptoService
+import im.vector.matrix.android.api.session.events.model.Event
+import im.vector.matrix.android.api.session.room.send.SendState
+import im.vector.matrix.android.internal.crypto.model.MXEncryptEventContentResult
+import im.vector.matrix.android.internal.session.room.send.LocalEchoUpdater
+import im.vector.matrix.android.internal.task.Task
+import im.vector.matrix.android.internal.util.awaitCallback
+import javax.inject.Inject
+
+internal interface EncryptEventTask : Task<EncryptEventTask.Params, Event> {
+    data class Params(val roomId: String,
+                      val event: Event,
+                      /**Do not encrypt these keys, keep them as is in encrypted content (e.g. m.relates_to)*/
+                      val keepKeys: List<String>? = null,
+                      val crypto: CryptoService
+    )
+}
+
+internal class DefaultEncryptEventTask @Inject constructor(
+//        private val crypto: CryptoService
+        private val localEchoUpdater: LocalEchoUpdater
+) : EncryptEventTask {
+    override suspend fun execute(params: EncryptEventTask.Params): Event {
+        if (!params.crypto.isRoomEncrypted(params.roomId)) return params.event
+        val localEvent = params.event
+        if (localEvent.eventId == null) {
+            throw IllegalArgumentException()
+        }
+
+        localEchoUpdater.updateSendState(localEvent.eventId, SendState.ENCRYPTING)
+
+        val localMutableContent = localEvent.content?.toMutableMap() ?: mutableMapOf()
+        params.keepKeys?.forEach {
+            localMutableContent.remove(it)
+        }
+
+//        try {
+        awaitCallback<MXEncryptEventContentResult> {
+            params.crypto.encryptEventContent(localMutableContent, localEvent.type, params.roomId, it)
+        }.let { result ->
+            val modifiedContent = HashMap(result.eventContent)
+            params.keepKeys?.forEach { toKeep ->
+                localEvent.content?.get(toKeep)?.let {
+                    // put it back in the encrypted thing
+                    modifiedContent[toKeep] = it
+                }
+            }
+            val safeResult = result.copy(eventContent = modifiedContent)
+            return localEvent.copy(
+                    type = safeResult.eventType,
+                    content = safeResult.eventContent
+            )
+        }
+//        } catch (throwable: Throwable) {
+//            val sendState = when (throwable) {
+//                is Failure.CryptoError -> SendState.FAILED_UNKNOWN_DEVICES
+//                else                   -> SendState.UNDELIVERED
+//            }
+//            localEchoUpdater.updateSendState(localEvent.eventId, sendState)
+//            throw throwable
+//        }
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/RequestVerificationDMTask.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/RequestVerificationDMTask.kt
new file mode 100644
index 0000000000..57d225a193
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/RequestVerificationDMTask.kt
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.tasks
+
+import com.zhuinden.monarchy.Monarchy
+import im.vector.matrix.android.api.session.crypto.CryptoService
+import im.vector.matrix.android.api.session.events.model.Event
+import im.vector.matrix.android.api.session.room.send.SendState
+import im.vector.matrix.android.internal.network.executeRequest
+import im.vector.matrix.android.internal.session.room.RoomAPI
+import im.vector.matrix.android.internal.session.room.send.LocalEchoEventFactory
+import im.vector.matrix.android.internal.session.room.send.LocalEchoUpdater
+import im.vector.matrix.android.internal.session.room.send.SendResponse
+import im.vector.matrix.android.internal.task.Task
+import javax.inject.Inject
+
+internal interface RequestVerificationDMTask : Task<RequestVerificationDMTask.Params, SendResponse> {
+    data class Params(
+            val roomId: String,
+            val from: String,
+            val methods: List<String>,
+            val to: String,
+            val cryptoService: CryptoService
+    )
+}
+
+internal class DefaultRequestVerificationDMTask @Inject constructor(
+        private val localEchoUpdater: LocalEchoUpdater,
+        private val localEchoEventFactory: LocalEchoEventFactory,
+        private val encryptEventTask: DefaultEncryptEventTask,
+        private val monarchy: Monarchy,
+        private val roomAPI: RoomAPI)
+    : RequestVerificationDMTask {
+
+    override suspend fun execute(params: RequestVerificationDMTask.Params): SendResponse {
+        val event = createRequestEvent(params)
+        val localID = event.eventId!!
+
+        try {
+            localEchoUpdater.updateSendState(localID, SendState.SENDING)
+            val executeRequest = executeRequest<SendResponse> {
+                apiCall = roomAPI.send(
+                        localID,
+                        roomId = params.roomId,
+                        content = event.content,
+                        eventType = event.type // message or room.encrypted
+                )
+            }
+            localEchoUpdater.updateSendState(localID, SendState.SENT)
+            return executeRequest
+        } catch (e: Throwable) {
+            localEchoUpdater.updateSendState(localID, SendState.UNDELIVERED)
+            throw e
+        }
+    }
+
+    private suspend fun createRequestEvent(params: RequestVerificationDMTask.Params): Event {
+        val event = localEchoEventFactory.createVerificationRequest(params.roomId, params.from, params.to, params.methods).also {
+            localEchoEventFactory.saveLocalEcho(monarchy, it)
+        }
+        if (params.cryptoService.isRoomEncrypted(params.roomId)) {
+            try {
+                return encryptEventTask.execute(EncryptEventTask.Params(
+                        params.roomId,
+                        event,
+                        listOf("m.relates_to"),
+                        params.cryptoService
+                ))
+            } catch (throwable: Throwable) {
+                // We said it's ok to send verification request in clear
+            }
+        }
+        return event
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/SendVerificationMessageTask.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/SendVerificationMessageTask.kt
new file mode 100644
index 0000000000..b850a1a1e6
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/SendVerificationMessageTask.kt
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.tasks
+
+import com.zhuinden.monarchy.Monarchy
+import im.vector.matrix.android.api.session.crypto.CryptoService
+import im.vector.matrix.android.api.session.events.model.Content
+import im.vector.matrix.android.api.session.events.model.Event
+import im.vector.matrix.android.api.session.events.model.LocalEcho
+import im.vector.matrix.android.api.session.events.model.UnsignedData
+import im.vector.matrix.android.api.session.room.send.SendState
+import im.vector.matrix.android.internal.di.UserId
+import im.vector.matrix.android.internal.network.executeRequest
+import im.vector.matrix.android.internal.session.room.RoomAPI
+import im.vector.matrix.android.internal.session.room.send.LocalEchoEventFactory
+import im.vector.matrix.android.internal.session.room.send.LocalEchoUpdater
+import im.vector.matrix.android.internal.session.room.send.SendResponse
+import im.vector.matrix.android.internal.task.Task
+import javax.inject.Inject
+
+internal interface SendVerificationMessageTask : Task<SendVerificationMessageTask.Params, SendResponse> {
+    data class Params(
+            val type: String,
+            val roomId: String,
+            val content: Content,
+            val cryptoService: CryptoService?
+    )
+}
+
+internal class DefaultSendVerificationMessageTask @Inject constructor(
+        private val localEchoUpdater: LocalEchoUpdater,
+        private val localEchoEventFactory: LocalEchoEventFactory,
+        private val encryptEventTask: DefaultEncryptEventTask,
+        private val monarchy: Monarchy,
+        @UserId private val userId: String,
+        private val roomAPI: RoomAPI) : SendVerificationMessageTask {
+
+    override suspend fun execute(params: SendVerificationMessageTask.Params): SendResponse {
+        val event = createRequestEvent(params)
+        val localID = event.eventId!!
+
+        try {
+            localEchoUpdater.updateSendState(localID, SendState.SENDING)
+            val executeRequest = executeRequest<SendResponse> {
+                apiCall = roomAPI.send(
+                        localID,
+                        roomId = params.roomId,
+                        content = event.content,
+                        eventType = event.type
+                )
+            }
+            localEchoUpdater.updateSendState(localID, SendState.SENT)
+            return executeRequest
+        } catch (e: Throwable) {
+            localEchoUpdater.updateSendState(localID, SendState.UNDELIVERED)
+            throw e
+        }
+    }
+
+    private suspend fun createRequestEvent(params: SendVerificationMessageTask.Params): Event {
+        val localID = LocalEcho.createLocalEchoId()
+        val event = Event(
+                roomId = params.roomId,
+                originServerTs = System.currentTimeMillis(),
+                senderId = userId,
+                eventId = localID,
+                type = params.type,
+                content = params.content,
+                unsignedData = UnsignedData(age = null, transactionId = localID)
+        ).also {
+            localEchoEventFactory.saveLocalEcho(monarchy, it)
+        }
+
+        if (params.cryptoService?.isRoomEncrypted(params.roomId) == true) {
+            try {
+                return encryptEventTask.execute(EncryptEventTask.Params(
+                        params.roomId,
+                        event,
+                        listOf("m.relates_to"),
+                        params.cryptoService
+                ))
+            } catch (throwable: Throwable) {
+                // We said it's ok to send verification request in clear
+            }
+        }
+        return event
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/IncomingSASVerificationTransaction.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultIncomingSASVerificationTransaction.kt
similarity index 79%
rename from matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/IncomingSASVerificationTransaction.kt
rename to matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultIncomingSASVerificationTransaction.kt
index 6ed5be4881..aac2b49f57 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/IncomingSASVerificationTransaction.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultIncomingSASVerificationTransaction.kt
@@ -16,6 +16,7 @@
 package im.vector.matrix.android.internal.crypto.verification
 
 import android.util.Base64
+import im.vector.matrix.android.BuildConfig
 import im.vector.matrix.android.api.auth.data.Credentials
 import im.vector.matrix.android.api.session.crypto.sas.CancelCode
 import im.vector.matrix.android.api.session.crypto.sas.IncomingSasVerificationTransaction
@@ -23,33 +24,20 @@ import im.vector.matrix.android.api.session.crypto.sas.SasMode
 import im.vector.matrix.android.api.session.crypto.sas.SasVerificationTxState
 import im.vector.matrix.android.api.session.events.model.EventType
 import im.vector.matrix.android.internal.crypto.actions.SetDeviceVerificationAction
-import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationAccept
-import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationKey
-import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationMac
-import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationStart
 import im.vector.matrix.android.internal.crypto.store.IMXCryptoStore
-import im.vector.matrix.android.internal.crypto.tasks.SendToDeviceTask
-import im.vector.matrix.android.internal.task.TaskExecutor
-import im.vector.matrix.android.internal.util.JsonCanonicalizer
 import timber.log.Timber
 
-internal class IncomingSASVerificationTransaction(
-        private val sasVerificationService: DefaultSasVerificationService,
-        private val setDeviceVerificationAction: SetDeviceVerificationAction,
-        private val credentials: Credentials,
+internal class DefaultIncomingSASVerificationTransaction(
+        setDeviceVerificationAction: SetDeviceVerificationAction,
+        override val credentials: Credentials,
         private val cryptoStore: IMXCryptoStore,
-        private val sendToDeviceTask: SendToDeviceTask,
-        private val taskExecutor: TaskExecutor,
         deviceFingerprint: String,
         transactionId: String,
-        otherUserID: String)
-    : SASVerificationTransaction(
-        sasVerificationService,
+        otherUserID: String
+) : SASVerificationTransaction(
         setDeviceVerificationAction,
         credentials,
         cryptoStore,
-        sendToDeviceTask,
-        taskExecutor,
         deviceFingerprint,
         transactionId,
         otherUserID,
@@ -78,10 +66,10 @@ internal class IncomingSASVerificationTransaction(
             }
         }
 
-    override fun onVerificationStart(startReq: KeyVerificationStart) {
-        Timber.v("## SAS received verification request from state $state")
+    override fun onVerificationStart(startReq: VerifInfoStart) {
+        Timber.v("## SAS I: received verification request from state $state")
         if (state != SasVerificationTxState.None) {
-            Timber.e("## received verification request from invalid state")
+            Timber.e("## SAS I: received verification request from invalid state")
             // should I cancel??
             throw IllegalStateException("Interactive Key verification already started")
         }
@@ -92,7 +80,7 @@ internal class IncomingSASVerificationTransaction(
 
     override fun performAccept() {
         if (state != SasVerificationTxState.OnStarted) {
-            Timber.e("## Cannot perform accept from state $state")
+            Timber.e("## SAS Cannot perform accept from state $state")
             return
         }
 
@@ -109,7 +97,7 @@ internal class IncomingSASVerificationTransaction(
         if (listOf(agreedProtocol, agreedHash, agreedMac).any { it.isNullOrBlank() }
                 || agreedShortCode.isNullOrEmpty()) {
             // Failed to find agreement
-            Timber.e("## Failed to find agreement ")
+            Timber.e("## SAS Failed to find agreement ")
             cancel(CancelCode.UnknownMethod)
             return
         }
@@ -118,15 +106,15 @@ internal class IncomingSASVerificationTransaction(
         val mxDeviceInfo = cryptoStore.getUserDevice(deviceId = otherDeviceId!!, userId = otherUserId)
 
         if (mxDeviceInfo?.fingerprint() == null) {
-            Timber.e("## Failed to find device key ")
+            Timber.e("## SAS Failed to find device key ")
             // TODO force download keys!!
             // would be probably better to download the keys
             // for now I cancel
             cancel(CancelCode.User)
         } else {
-            //                    val otherKey = info.identityKey()
+            // val otherKey = info.identityKey()
             // need to jump back to correct thread
-            val accept = KeyVerificationAccept.create(
+            val accept = transport.createAccept(
                     tid = transactionId,
                     keyAgreementProtocol = agreedProtocol!!,
                     hash = agreedHash!!,
@@ -138,13 +126,13 @@ internal class IncomingSASVerificationTransaction(
         }
     }
 
-    private fun doAccept(accept: KeyVerificationAccept) {
+    private fun doAccept(accept: VerifInfoAccept) {
         this.accepted = accept
-        Timber.v("## SAS accept request id:$transactionId")
+        Timber.v("## SAS incoming accept request id:$transactionId")
 
         // The hash commitment is the hash (using the selected hash algorithm) of the unpadded base64 representation of QB,
         // concatenated with the canonical JSON representation of the content of the m.key.verification.start message
-        val concat = getSAS().publicKey + JsonCanonicalizer.getCanonicalJson(KeyVerificationStart::class.java, startReq!!)
+        val concat = getSAS().publicKey + startReq!!.toCanonicalJson()
         accept.commitment = hashUsingAgreedHashMethod(concat) ?: ""
         // we need to send this to other device now
         state = SasVerificationTxState.SendingAccept
@@ -156,15 +144,15 @@ internal class IncomingSASVerificationTransaction(
         }
     }
 
-    override fun onVerificationAccept(accept: KeyVerificationAccept) {
+    override fun onVerificationAccept(accept: VerifInfoAccept) {
         Timber.v("## SAS invalid message for incoming request id:$transactionId")
         cancel(CancelCode.UnexpectedMessage)
     }
 
-    override fun onKeyVerificationKey(userId: String, vKey: KeyVerificationKey) {
+    override fun onKeyVerificationKey(userId: String, vKey: VerifInfoKey) {
         Timber.v("## SAS received key for request id:$transactionId")
         if (state != SasVerificationTxState.SendingAccept && state != SasVerificationTxState.Accepted) {
-            Timber.e("## received key from invalid state $state")
+            Timber.e("## SAS received key from invalid state $state")
             cancel(CancelCode.UnexpectedMessage)
             return
         }
@@ -175,7 +163,7 @@ internal class IncomingSASVerificationTransaction(
         // sending Bob’s public key QB
         val pubKey = getSAS().publicKey
 
-        val keyToDevice = KeyVerificationKey.create(transactionId, pubKey)
+        val keyToDevice = transport.createKey(transactionId, pubKey)
         // we need to send this to other device now
         state = SasVerificationTxState.SendingKey
         this.sendToOther(EventType.KEY_VERIFICATION_KEY, keyToDevice, SasVerificationTxState.KeySent, CancelCode.User) {
@@ -206,14 +194,16 @@ internal class IncomingSASVerificationTransaction(
         // emoji: generate six bytes by using HKDF.
         shortCodeBytes = getSAS().generateShortCode(sasInfo, 6)
 
-        Timber.e("************  BOB CODE ${getDecimalCodeRepresentation(shortCodeBytes!!)}")
-        Timber.e("************  BOB EMOJI CODE ${getShortCodeRepresentation(SasMode.EMOJI)}")
+        if (BuildConfig.LOG_PRIVATE_DATA) {
+            Timber.v("************  BOB CODE ${getDecimalCodeRepresentation(shortCodeBytes!!)}")
+            Timber.v("************  BOB EMOJI CODE ${getShortCodeRepresentation(SasMode.EMOJI)}")
+        }
 
         state = SasVerificationTxState.ShortCodeReady
     }
 
-    override fun onKeyVerificationMac(vKey: KeyVerificationMac) {
-        Timber.v("## SAS received mac for request id:$transactionId")
+    override fun onKeyVerificationMac(vKey: VerifInfoMac) {
+        Timber.v("## SAS I: received mac for request id:$transactionId")
         // Check for state?
         if (state != SasVerificationTxState.SendingKey
                 && state != SasVerificationTxState.KeySent
@@ -221,7 +211,7 @@ internal class IncomingSASVerificationTransaction(
                 && state != SasVerificationTxState.ShortCodeAccepted
                 && state != SasVerificationTxState.SendingMac
                 && state != SasVerificationTxState.MacSent) {
-            Timber.e("## received key from invalid state $state")
+            Timber.e("## SAS I: received key from invalid state $state")
             cancel(CancelCode.UnexpectedMessage)
             return
         }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/OutgoingSASVerificationRequest.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultOutgoingSASVerificationRequest.kt
similarity index 79%
rename from matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/OutgoingSASVerificationRequest.kt
rename to matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultOutgoingSASVerificationRequest.kt
index cade637cce..4362e897c8 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/OutgoingSASVerificationRequest.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultOutgoingSASVerificationRequest.kt
@@ -21,34 +21,22 @@ import im.vector.matrix.android.api.session.crypto.sas.OutgoingSasVerificationRe
 import im.vector.matrix.android.api.session.crypto.sas.SasVerificationTxState
 import im.vector.matrix.android.api.session.events.model.EventType
 import im.vector.matrix.android.internal.crypto.actions.SetDeviceVerificationAction
-import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationAccept
-import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationKey
-import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationMac
 import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationStart
 import im.vector.matrix.android.internal.crypto.store.IMXCryptoStore
-import im.vector.matrix.android.internal.crypto.tasks.SendToDeviceTask
-import im.vector.matrix.android.internal.task.TaskExecutor
-import im.vector.matrix.android.internal.util.JsonCanonicalizer
 import timber.log.Timber
 
-internal class OutgoingSASVerificationRequest(
-        private val sasVerificationService: DefaultSasVerificationService,
-        private val setDeviceVerificationAction: SetDeviceVerificationAction,
-        private val credentials: Credentials,
-        private val cryptoStore: IMXCryptoStore,
-        private val sendToDeviceTask: SendToDeviceTask,
-        private val taskExecutor: TaskExecutor,
+internal class DefaultOutgoingSASVerificationRequest(
+        setDeviceVerificationAction: SetDeviceVerificationAction,
+        credentials: Credentials,
+        cryptoStore: IMXCryptoStore,
         deviceFingerprint: String,
         transactionId: String,
         otherUserId: String,
-        otherDeviceId: String)
-    : SASVerificationTransaction(
-        sasVerificationService,
+        otherDeviceId: String
+) : SASVerificationTransaction(
         setDeviceVerificationAction,
         credentials,
         cryptoStore,
-        sendToDeviceTask,
-        taskExecutor,
         deviceFingerprint,
         transactionId,
         otherUserId,
@@ -78,14 +66,14 @@ internal class OutgoingSASVerificationRequest(
             }
         }
 
-    override fun onVerificationStart(startReq: KeyVerificationStart) {
-        Timber.e("## onVerificationStart - unexpected id:$transactionId")
+    override fun onVerificationStart(startReq: VerifInfoStart) {
+        Timber.e("## SAS O: onVerificationStart - unexpected id:$transactionId")
         cancel(CancelCode.UnexpectedMessage)
     }
 
     fun start() {
         if (state != SasVerificationTxState.None) {
-            Timber.e("## start verification from invalid state")
+            Timber.e("## SAS O: start verification from invalid state")
             // should I cancel??
             throw IllegalStateException("Interactive Key verification already started")
         }
@@ -111,10 +99,33 @@ internal class OutgoingSASVerificationRequest(
         )
     }
 
-    override fun onVerificationAccept(accept: KeyVerificationAccept) {
-        Timber.v("## onVerificationAccept id:$transactionId")
+//    fun request() {
+//        if (state != SasVerificationTxState.None) {
+//            Timber.e("## start verification from invalid state")
+//            // should I cancel??
+//            throw IllegalStateException("Interactive Key verification already started")
+//        }
+//
+//        val requestMessage = KeyVerificationRequest(
+//                fromDevice = session.sessionParams.credentials.deviceId ?: "",
+//                methods = listOf(KeyVerificationStart.VERIF_METHOD_SAS),
+//                timestamp = System.currentTimeMillis().toInt(),
+//                transactionID = transactionId
+//        )
+//
+//        sendToOther(
+//                EventType.KEY_VERIFICATION_REQUEST,
+//                requestMessage,
+//                SasVerificationTxState.None,
+//                CancelCode.User,
+//                null
+//        )
+//    }
+
+    override fun onVerificationAccept(accept: VerifInfoAccept) {
+        Timber.v("## SAS O: onVerificationAccept id:$transactionId")
         if (state != SasVerificationTxState.Started) {
-            Timber.e("## received accept request from invalid state $state")
+            Timber.e("## SAS O: received accept request from invalid state $state")
             cancel(CancelCode.UnexpectedMessage)
             return
         }
@@ -123,7 +134,7 @@ internal class OutgoingSASVerificationRequest(
                 || !KNOWN_HASHES.contains(accept.hash)
                 || !KNOWN_MACS.contains(accept.messageAuthenticationCode)
                 || accept.shortAuthenticationStrings!!.intersect(KNOWN_SHORT_CODES).isEmpty()) {
-            Timber.e("## received accept request from invalid state")
+            Timber.e("## SAS O: received accept request from invalid state")
             cancel(CancelCode.UnknownMethod)
             return
         }
@@ -137,7 +148,7 @@ internal class OutgoingSASVerificationRequest(
         // and replies with a to_device message with type set to “m.key.verification.key”, sending Alice’s public key QA
         val pubKey = getSAS().publicKey
 
-        val keyToDevice = KeyVerificationKey.create(transactionId, pubKey)
+        val keyToDevice = transport.createKey(transactionId, pubKey)
         // we need to send this to other device now
         state = SasVerificationTxState.SendingKey
         sendToOther(EventType.KEY_VERIFICATION_KEY, keyToDevice, SasVerificationTxState.KeySent, CancelCode.User) {
@@ -148,8 +159,8 @@ internal class OutgoingSASVerificationRequest(
         }
     }
 
-    override fun onKeyVerificationKey(userId: String, vKey: KeyVerificationKey) {
-        Timber.v("## onKeyVerificationKey id:$transactionId")
+    override fun onKeyVerificationKey(userId: String, vKey: VerifInfoKey) {
+        Timber.v("## SAS O: onKeyVerificationKey id:$transactionId")
         if (state != SasVerificationTxState.SendingKey && state != SasVerificationTxState.KeySent) {
             Timber.e("## received key from invalid state $state")
             cancel(CancelCode.UnexpectedMessage)
@@ -163,7 +174,7 @@ internal class OutgoingSASVerificationRequest(
         // in Bob’s m.key.verification.key and the content of Alice’s m.key.verification.start message.
 
         // check commitment
-        val concat = vKey.key + JsonCanonicalizer.getCanonicalJson(KeyVerificationStart::class.java, startReq!!)
+        val concat = vKey.key + startReq!!.toCanonicalJson()
         val otherCommitment = hashUsingAgreedHashMethod(concat) ?: ""
 
         if (accepted!!.commitment.equals(otherCommitment)) {
@@ -190,14 +201,14 @@ internal class OutgoingSASVerificationRequest(
         }
     }
 
-    override fun onKeyVerificationMac(vKey: KeyVerificationMac) {
-        Timber.v("## onKeyVerificationMac id:$transactionId")
+    override fun onKeyVerificationMac(vKey: VerifInfoMac) {
+        Timber.v("## SAS O: onKeyVerificationMac id:$transactionId")
         if (state != SasVerificationTxState.OnKeyReceived
                 && state != SasVerificationTxState.ShortCodeReady
                 && state != SasVerificationTxState.ShortCodeAccepted
                 && state != SasVerificationTxState.SendingMac
                 && state != SasVerificationTxState.MacSent) {
-            Timber.e("## received key from invalid state $state")
+            Timber.e("## SAS O: received key from invalid state $state")
             cancel(CancelCode.UnexpectedMessage)
             return
         }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt
index e0cd47e0e0..6552dca7ab 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt
@@ -21,6 +21,7 @@ import android.os.Looper
 import dagger.Lazy
 import im.vector.matrix.android.api.MatrixCallback
 import im.vector.matrix.android.api.auth.data.Credentials
+import im.vector.matrix.android.api.session.crypto.CryptoService
 import im.vector.matrix.android.api.session.crypto.sas.CancelCode
 import im.vector.matrix.android.api.session.crypto.sas.SasVerificationService
 import im.vector.matrix.android.api.session.crypto.sas.SasVerificationTxState
@@ -28,6 +29,7 @@ import im.vector.matrix.android.api.session.crypto.sas.safeValueOf
 import im.vector.matrix.android.api.session.events.model.Event
 import im.vector.matrix.android.api.session.events.model.EventType
 import im.vector.matrix.android.api.session.events.model.toModel
+import im.vector.matrix.android.api.session.room.model.message.*
 import im.vector.matrix.android.internal.crypto.DeviceListManager
 import im.vector.matrix.android.internal.crypto.MyDeviceInfoHolder
 import im.vector.matrix.android.internal.crypto.actions.SetDeviceVerificationAction
@@ -35,24 +37,23 @@ import im.vector.matrix.android.internal.crypto.model.MXDeviceInfo
 import im.vector.matrix.android.internal.crypto.model.MXUsersDevicesMap
 import im.vector.matrix.android.internal.crypto.model.rest.*
 import im.vector.matrix.android.internal.crypto.store.IMXCryptoStore
+import im.vector.matrix.android.internal.crypto.tasks.DefaultRequestVerificationDMTask
+import im.vector.matrix.android.internal.crypto.tasks.RequestVerificationDMTask
 import im.vector.matrix.android.internal.crypto.tasks.SendToDeviceTask
 import im.vector.matrix.android.internal.session.SessionScope
+import im.vector.matrix.android.internal.session.room.send.SendResponse
+import im.vector.matrix.android.internal.task.TaskConstraints
 import im.vector.matrix.android.internal.task.TaskExecutor
 import im.vector.matrix.android.internal.task.configureWith
 import im.vector.matrix.android.internal.util.MatrixCoroutineDispatchers
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import timber.log.Timber
-import java.lang.Exception
-import java.util.UUID
+import java.util.*
 import javax.inject.Inject
+import kotlin.collections.ArrayList
 import kotlin.collections.HashMap
-
-/**
- * Manages all current verifications transactions with short codes.
- * Short codes interactive verification is a more user friendly way of verifying devices
- * that is still maintaining a good level of security (alternative to the 43-character strings compare method).
- */
+import kotlin.collections.set
 
 @SessionScope
 internal class DefaultSasVerificationService @Inject constructor(private val credentials: Credentials,
@@ -61,12 +62,18 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
                                                                  private val deviceListManager: DeviceListManager,
                                                                  private val setDeviceVerificationAction: SetDeviceVerificationAction,
                                                                  private val sendToDeviceTask: SendToDeviceTask,
+                                                                 private val requestVerificationDMTask: DefaultRequestVerificationDMTask,
                                                                  private val coroutineDispatchers: MatrixCoroutineDispatchers,
+                                                                 private val sasTransportRoomMessageFactory: SasTransportRoomMessageFactory,
+                                                                 private val sasToDeviceTransportFactory: SasToDeviceTransportFactory,
                                                                  private val taskExecutor: TaskExecutor)
     : VerificationTransaction.Listener, SasVerificationService {
 
     private val uiHandler = Handler(Looper.getMainLooper())
 
+    // Cannot be injected in constructor as it creates a dependency cycle
+    lateinit var cryptoService: CryptoService
+
     // map [sender : [transaction]]
     private val txMap = HashMap<String, HashMap<String, VerificationTransaction>>()
 
@@ -96,6 +103,39 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
         }
     }
 
+    fun onRoomEvent(event: Event) {
+        GlobalScope.launch(coroutineDispatchers.crypto) {
+            when (event.getClearType()) {
+                EventType.KEY_VERIFICATION_START  -> {
+                    onRoomStartRequestReceived(event)
+                }
+                EventType.KEY_VERIFICATION_CANCEL -> {
+                    onRoomCancelReceived(event)
+                }
+                EventType.KEY_VERIFICATION_ACCEPT -> {
+                    onRoomAcceptReceived(event)
+                }
+                EventType.KEY_VERIFICATION_KEY    -> {
+                    onRoomKeyRequestReceived(event)
+                }
+                EventType.KEY_VERIFICATION_MAC    -> {
+                    onRoomMacReceived(event)
+                }
+                EventType.KEY_VERIFICATION_DONE   -> {
+                    // TODO?
+                }
+                EventType.MESSAGE                 -> {
+                    if (MessageType.MSGTYPE_VERIFICATION_REQUEST == event.getClearContent().toModel<MessageContent>()?.type) {
+                        onRoomRequestReceived(event)
+                    }
+                }
+                else                              -> {
+                    // ignore
+                }
+            }
+        }
+    }
+
     private var listeners = ArrayList<SasVerificationService.SasVerificationListener>()
 
     override fun addListener(listener: SasVerificationService.SasVerificationListener) {
@@ -150,15 +190,64 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
         }
     }
 
+    fun onRoomRequestReceived(event: Event) {
+        // TODO
+        Timber.v("## SAS Verification request from ${event.senderId} in room ${event.roomId}")
+    }
+
+    private suspend fun onRoomStartRequestReceived(event: Event) {
+        val startReq = event.getClearContent().toModel<MessageVerificationStartContent>()
+                ?.copy(
+                        // relates_to is in clear in encrypted payload
+                        relatesTo = event.content.toModel<MessageRelationContent>()?.relatesTo
+                )
+
+        val otherUserId = event.senderId
+        if (startReq?.isValid()?.not() == true) {
+            Timber.e("## received invalid verification request")
+            if (startReq.transactionID != null) {
+                sasTransportRoomMessageFactory.createTransport(event.roomId
+                        ?: "", cryptoService).cancelTransaction(
+                        startReq.transactionID ?: "",
+                        otherUserId!!,
+                        startReq.fromDevice ?: event.getSenderKey()!!,
+                        CancelCode.UnknownMethod
+                )
+            }
+            return
+        }
+
+        handleStart(otherUserId, startReq as VerifInfoStart) {
+            it.transport = sasTransportRoomMessageFactory.createTransport(event.roomId
+                    ?: "", cryptoService)
+        }?.let {
+            sasTransportRoomMessageFactory.createTransport(event.roomId
+                    ?: "", cryptoService).cancelTransaction(
+                    startReq.transactionID ?: "",
+                    otherUserId!!,
+                    startReq.fromDevice ?: event.getSenderKey()!!,
+                    it
+            )
+        }
+    }
+
     private suspend fun onStartRequestReceived(event: Event) {
+        Timber.e("## SAS received Start request ${event.eventId}")
         val startReq = event.getClearContent().toModel<KeyVerificationStart>()!!
+        Timber.v("## SAS received Start request $startReq")
 
         val otherUserId = event.senderId
         if (!startReq.isValid()) {
-            Timber.e("## received invalid verification request")
+            Timber.e("## SAS received invalid verification request")
             if (startReq.transactionID != null) {
-                cancelTransaction(
-                        startReq.transactionID!!,
+//                cancelTransaction(
+//                        startReq.transactionID!!,
+//                        otherUserId!!,
+//                        startReq.fromDevice ?: event.getSenderKey()!!,
+//                        CancelCode.UnknownMethod
+//                )
+                sasToDeviceTransportFactory.createTransport(null).cancelTransaction(
+                        startReq.transactionID ?: "",
                         otherUserId!!,
                         startReq.fromDevice ?: event.getSenderKey()!!,
                         CancelCode.UnknownMethod
@@ -167,8 +256,22 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
             return
         }
         // Download device keys prior to everything
+        handleStart(otherUserId, startReq) {
+            it.transport = sasToDeviceTransportFactory.createTransport(it)
+        }?.let {
+            sasToDeviceTransportFactory.createTransport(null).cancelTransaction(
+                    startReq.transactionID ?: "",
+                    otherUserId!!,
+                    startReq.fromDevice ?: event.getSenderKey()!!,
+                    it
+            )
+        }
+    }
+
+    private suspend fun handleStart(otherUserId: String?, startReq: VerifInfoStart, txConfigure: (SASVerificationTransaction) -> Unit): CancelCode? {
+        Timber.d("## SAS onStartRequestReceived ${startReq.transactionID!!}")
         if (checkKeysAreDownloaded(otherUserId!!, startReq) != null) {
-            Timber.v("## SAS onStartRequestReceived ${startReq.transactionID!!}")
+            Timber.v("## SAS onStartRequestReceived $startReq")
             val tid = startReq.transactionID!!
             val existing = getExistingTransaction(otherUserId, tid)
             val existingTxs = getExistingTransactionsForUser(otherUserId)
@@ -176,43 +279,46 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
                 // should cancel both!
                 Timber.v("## SAS onStartRequestReceived - Request exist with same if ${startReq.transactionID!!}")
                 existing.cancel(CancelCode.UnexpectedMessage)
-                cancelTransaction(tid, otherUserId, startReq.fromDevice!!, CancelCode.UnexpectedMessage)
+                return CancelCode.UnexpectedMessage
+                // cancelTransaction(tid, otherUserId, startReq.fromDevice!!, CancelCode.UnexpectedMessage)
             } else if (existingTxs?.isEmpty() == false) {
                 Timber.v("## SAS onStartRequestReceived - There is already a transaction with this user ${startReq.transactionID!!}")
                 // Multiple keyshares between two devices: any two devices may only have at most one key verification in flight at a time.
                 existingTxs.forEach {
                     it.cancel(CancelCode.UnexpectedMessage)
                 }
-                cancelTransaction(tid, otherUserId, startReq.fromDevice!!, CancelCode.UnexpectedMessage)
+                return CancelCode.UnexpectedMessage
+                // cancelTransaction(tid, otherUserId, startReq.fromDevice!!, CancelCode.UnexpectedMessage)
             } else {
                 // Ok we can create
                 if (KeyVerificationStart.VERIF_METHOD_SAS == startReq.method) {
                     Timber.v("## SAS onStartRequestReceived - request accepted ${startReq.transactionID!!}")
-                    val tx = IncomingSASVerificationTransaction(
-                            this,
+                    val tx = DefaultIncomingSASVerificationTransaction(
+//                            this,
                             setDeviceVerificationAction,
                             credentials,
                             cryptoStore,
-                            sendToDeviceTask,
-                            taskExecutor,
                             myDeviceInfoHolder.get().myDevice.fingerprint()!!,
                             startReq.transactionID!!,
-                            otherUserId)
+                            otherUserId).also { txConfigure(it) }
                     addTransaction(tx)
-                    tx.acceptToDeviceEvent(otherUserId, startReq)
+                    tx.acceptVerificationEvent(otherUserId, startReq)
                 } else {
                     Timber.e("## SAS onStartRequestReceived - unknown method ${startReq.method}")
-                    cancelTransaction(tid, otherUserId, startReq.fromDevice
-                            ?: event.getSenderKey()!!, CancelCode.UnknownMethod)
+                    return CancelCode.UnknownMethod
+                    // cancelTransaction(tid, otherUserId, startReq.fromDevice
+//                            ?: event.getSenderKey()!!, CancelCode.UnknownMethod)
                 }
             }
         } else {
-            cancelTransaction(startReq.transactionID!!, otherUserId, startReq.fromDevice!!, CancelCode.UnexpectedMessage)
+            return CancelCode.UnexpectedMessage
+//            cancelTransaction(startReq.transactionID!!, otherUserId, startReq.fromDevice!!, CancelCode.UnexpectedMessage)
         }
+        return null
     }
 
     private suspend fun checkKeysAreDownloaded(otherUserId: String,
-                                               startReq: KeyVerificationStart): MXUsersDevicesMap<MXDeviceInfo>? {
+                                               startReq: VerifInfoStart): MXUsersDevicesMap<MXDeviceInfo>? {
         return try {
             val keys = deviceListManager.downloadKeys(listOf(otherUserId), true)
             val deviceIds = keys.getUserDeviceIds(otherUserId) ?: return null
@@ -222,17 +328,36 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
         }
     }
 
-    private suspend fun onCancelReceived(event: Event) {
+    private fun onRoomCancelReceived(event: Event) {
+        val cancelReq = event.getClearContent().toModel<MessageVerificationCancelContent>()
+                ?.copy(
+                        // relates_to is in clear in encrypted payload
+                        relatesTo = event.content.toModel<MessageRelationContent>()?.relatesTo
+                )
+        if (cancelReq == null || cancelReq.isValid().not()) {
+            // ignore
+            Timber.e("## SAS Received invalid key request")
+            // TODO should we cancel?
+            return
+        }
+        handleOnCancel(event.senderId!!, cancelReq)
+    }
+
+    private fun onCancelReceived(event: Event) {
         Timber.v("## SAS onCancelReceived")
         val cancelReq = event.getClearContent().toModel<KeyVerificationCancel>()!!
 
         if (!cancelReq.isValid()) {
             // ignore
-            Timber.e("## Received invalid accept request")
+            Timber.e("## SAS Received invalid accept request")
             return
         }
         val otherUserId = event.senderId!!
 
+        handleOnCancel(otherUserId, cancelReq)
+    }
+
+    private fun handleOnCancel(otherUserId: String, cancelReq: VerifInfoCancel) {
         Timber.v("## SAS onCancelReceived otherUser:$otherUserId reason:${cancelReq.reason}")
         val existing = getExistingTransaction(otherUserId, cancelReq.transactionID!!)
         if (existing == null) {
@@ -245,65 +370,119 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
         }
     }
 
-    private suspend fun onAcceptReceived(event: Event) {
-        val acceptReq = event.getClearContent().toModel<KeyVerificationAccept>()!!
+    private fun onRoomAcceptReceived(event: Event) {
+        Timber.d("##  SAS Received Accept via DM $event")
+        val accept = event.getClearContent().toModel<MessageVerificationAcceptContent>()
+                ?.copy(
+                        // relates_to is in clear in encrypted payload
+                        relatesTo = event.content.toModel<MessageRelationContent>()?.relatesTo
+                )
+                ?: return
+        handleAccept(accept, event.senderId!!)
+    }
 
+    private fun onAcceptReceived(event: Event) {
+        Timber.d("##  SAS Received Accept $event")
+        val acceptReq = event.getClearContent().toModel<KeyVerificationAccept>() ?: return
+        handleAccept(acceptReq, event.senderId!!)
+    }
+
+    private fun handleAccept(acceptReq: VerifInfoAccept, senderId: String) {
         if (!acceptReq.isValid()) {
             // ignore
-            Timber.e("## Received invalid accept request")
+            Timber.e("## SAS Received invalid accept request")
             return
         }
-        val otherUserId = event.senderId!!
+        val otherUserId = senderId
         val existing = getExistingTransaction(otherUserId, acceptReq.transactionID!!)
         if (existing == null) {
-            Timber.e("## Received invalid accept request")
+            Timber.e("## SAS Received invalid accept request")
             return
         }
 
         if (existing is SASVerificationTransaction) {
-            existing.acceptToDeviceEvent(otherUserId, acceptReq)
+            existing.acceptVerificationEvent(otherUserId, acceptReq)
         } else {
             // not other types now
         }
     }
 
-    private suspend fun onKeyReceived(event: Event) {
+    private fun onRoomKeyRequestReceived(event: Event) {
+        val keyReq = event.getClearContent().toModel<MessageVerificationKeyContent>()
+                ?.copy(
+                        // relates_to is in clear in encrypted payload
+                        relatesTo = event.content.toModel<MessageRelationContent>()?.relatesTo
+                )
+        if (keyReq == null || keyReq.isValid().not()) {
+            // ignore
+            Timber.e("## SAS Received invalid key request")
+            // TODO should we cancel?
+            return
+        }
+        handleKeyReceived(event, keyReq)
+    }
+
+    private fun onKeyReceived(event: Event) {
         val keyReq = event.getClearContent().toModel<KeyVerificationKey>()!!
 
         if (!keyReq.isValid()) {
             // ignore
-            Timber.e("## Received invalid key request")
+            Timber.e("## SAS Received invalid key request")
             return
         }
+        handleKeyReceived(event, keyReq)
+    }
+
+    private fun handleKeyReceived(event: Event, keyReq: VerifInfoKey) {
+        Timber.d("##  SAS Received Key from ${event.senderId} with info $keyReq")
         val otherUserId = event.senderId!!
         val existing = getExistingTransaction(otherUserId, keyReq.transactionID!!)
         if (existing == null) {
-            Timber.e("## Received invalid accept request")
+            Timber.e("##  SAS Received invalid accept request")
             return
         }
         if (existing is SASVerificationTransaction) {
-            existing.acceptToDeviceEvent(otherUserId, keyReq)
+            existing.acceptVerificationEvent(otherUserId, keyReq)
         } else {
             // not other types now
         }
     }
 
-    private suspend fun onMacReceived(event: Event) {
-        val macReq = event.getClearContent().toModel<KeyVerificationMac>()!!
-
-        if (!macReq.isValid()) {
+    private fun onRoomMacReceived(event: Event) {
+        val macReq = event.getClearContent().toModel<MessageVerificationMacContent>()
+                ?.copy(
+                        // relates_to is in clear in encrypted payload
+                        relatesTo = event.content.toModel<MessageRelationContent>()?.relatesTo
+                )
+        if (macReq == null || macReq.isValid().not() || event.senderId == null) {
             // ignore
-            Timber.e("## Received invalid key request")
+            Timber.e("## SAS Received invalid mac request")
+            // TODO should we cancel?
             return
         }
-        val otherUserId = event.senderId!!
-        val existing = getExistingTransaction(otherUserId, macReq.transactionID!!)
+        handleMacReceived(event.senderId, macReq)
+    }
+
+    private fun onMacReceived(event: Event) {
+        val macReq = event.getClearContent().toModel<KeyVerificationMac>()!!
+
+        if (!macReq.isValid() || event.senderId == null) {
+            // ignore
+            Timber.e("## SAS Received invalid mac request")
+            return
+        }
+        handleMacReceived(event.senderId, macReq)
+    }
+
+    private fun handleMacReceived(senderId: String, macReq: VerifInfoMac) {
+        Timber.v("## SAS Received $macReq")
+        val existing = getExistingTransaction(senderId, macReq.transactionID!!)
         if (existing == null) {
-            Timber.e("## Received invalid accept request")
+            Timber.e("## SAS Received invalid accept request")
             return
         }
         if (existing is SASVerificationTransaction) {
-            existing.acceptToDeviceEvent(otherUserId, macReq)
+            existing.acceptVerificationEvent(senderId, macReq)
         } else {
             // not other types known for now
         }
@@ -346,13 +525,10 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
         val txID = createUniqueIDForTransaction(userId, deviceID)
         // should check if already one (and cancel it)
         if (KeyVerificationStart.VERIF_METHOD_SAS == method) {
-            val tx = OutgoingSASVerificationRequest(
-                    this,
+            val tx = DefaultOutgoingSASVerificationRequest(
                     setDeviceVerificationAction,
                     credentials,
                     cryptoStore,
-                    sendToDeviceTask,
-                    taskExecutor,
                     myDeviceInfoHolder.get().myDevice.fingerprint()!!,
                     txID,
                     userId,
@@ -366,6 +542,30 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
         }
     }
 
+    override fun requestKeyVerificationInDMs(userId: String, roomId: String, callback: MatrixCallback<String>?) {
+        requestVerificationDMTask.configureWith(
+                RequestVerificationDMTask.Params(
+                        roomId = roomId,
+                        from = credentials.deviceId ?: "",
+                        methods = listOf(KeyVerificationStart.VERIF_METHOD_SAS),
+                        to = userId,
+                        cryptoService = cryptoService
+                )
+        ) {
+            this.callback = object : MatrixCallback<SendResponse> {
+                override fun onSuccess(data: SendResponse) {
+                    callback?.onSuccess(data.eventId)
+                }
+
+                override fun onFailure(failure: Throwable) {
+                    callback?.onFailure(failure)
+                }
+            }
+            constraints = TaskConstraints(true)
+            retryCount = 3
+        }.executeBy(taskExecutor)
+    }
+
     /**
      * This string must be unique for the pair of users performing verification for the duration that the transaction is valid
      */
@@ -390,24 +590,28 @@ internal class DefaultSasVerificationService @Inject constructor(private val cre
             this.removeTransaction(tx.otherUserId, tx.transactionId)
         }
     }
-
-    fun cancelTransaction(transactionId: String, userId: String, userDevice: String, code: CancelCode) {
-        val cancelMessage = KeyVerificationCancel.create(transactionId, code)
-        val contentMap = MXUsersDevicesMap<Any>()
-        contentMap.setObject(userId, userDevice, cancelMessage)
-
-        sendToDeviceTask
-                .configureWith(SendToDeviceTask.Params(EventType.KEY_VERIFICATION_CANCEL, contentMap, transactionId)) {
-                    this.callback = object : MatrixCallback<Unit> {
-                        override fun onSuccess(data: Unit) {
-                            Timber.v("## SAS verification [$transactionId] canceled for reason ${code.value}")
-                        }
-
-                        override fun onFailure(failure: Throwable) {
-                            Timber.e(failure, "## SAS verification [$transactionId] failed to cancel.")
-                        }
-                    }
-                }
-                .executeBy(taskExecutor)
-    }
+//
+//    fun cancelTransaction(transactionId: String, userId: String, userDevice: String, code: CancelCode, roomId: String? = null) {
+//        val cancelMessage = KeyVerificationCancel.create(transactionId, code)
+//        val contentMap = MXUsersDevicesMap<Any>()
+//        contentMap.setObject(userId, userDevice, cancelMessage)
+//
+//        if (roomId != null) {
+//
+//        } else {
+//            sendToDeviceTask
+//                    .configureWith(SendToDeviceTask.Params(EventType.KEY_VERIFICATION_CANCEL, contentMap, transactionId)) {
+//                        this.callback = object : MatrixCallback<Unit> {
+//                            override fun onSuccess(data: Unit) {
+//                                Timber.v("## SAS verification [$transactionId] canceled for reason ${code.value}")
+//                            }
+//
+//                            override fun onFailure(failure: Throwable) {
+//                                Timber.e(failure, "## SAS verification [$transactionId] failed to cancel.")
+//                            }
+//                        }
+//                    }
+//                    .executeBy(taskExecutor)
+//        }
+//    }
 }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt
index 589103d38a..443443afad 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SASVerificationTransaction.kt
@@ -16,7 +16,6 @@
 package im.vector.matrix.android.internal.crypto.verification
 
 import android.os.Build
-import im.vector.matrix.android.api.MatrixCallback
 import im.vector.matrix.android.api.auth.data.Credentials
 import im.vector.matrix.android.api.session.crypto.sas.CancelCode
 import im.vector.matrix.android.api.session.crypto.sas.EmojiRepresentation
@@ -26,13 +25,8 @@ import im.vector.matrix.android.api.session.events.model.EventType
 import im.vector.matrix.android.internal.crypto.actions.SetDeviceVerificationAction
 import im.vector.matrix.android.internal.crypto.model.MXDeviceInfo
 import im.vector.matrix.android.internal.crypto.model.MXKey
-import im.vector.matrix.android.internal.crypto.model.MXUsersDevicesMap
-import im.vector.matrix.android.internal.crypto.model.rest.*
 import im.vector.matrix.android.internal.crypto.store.IMXCryptoStore
-import im.vector.matrix.android.internal.crypto.tasks.SendToDeviceTask
 import im.vector.matrix.android.internal.extensions.toUnsignedInt
-import im.vector.matrix.android.internal.task.TaskExecutor
-import im.vector.matrix.android.internal.task.configureWith
 import org.matrix.olm.OlmSAS
 import org.matrix.olm.OlmUtility
 import timber.log.Timber
@@ -42,12 +36,9 @@ import kotlin.properties.Delegates
  * Represents an ongoing short code interactive key verification between two devices.
  */
 internal abstract class SASVerificationTransaction(
-        private val sasVerificationService: DefaultSasVerificationService,
         private val setDeviceVerificationAction: SetDeviceVerificationAction,
-        private val credentials: Credentials,
+        open val credentials: Credentials,
         private val cryptoStore: IMXCryptoStore,
-        private val sendToDeviceTask: SendToDeviceTask,
-        private val taskExecutor: TaskExecutor,
         private val deviceFingerprint: String,
         transactionId: String,
         otherUserId: String,
@@ -55,6 +46,8 @@ internal abstract class SASVerificationTransaction(
         isIncoming: Boolean) :
         VerificationTransaction(transactionId, otherUserId, otherDevice, isIncoming) {
 
+    lateinit var transport: SasTransport
+
     companion object {
         const val SAS_MAC_SHA256_LONGKDF = "hmac-sha256"
         const val SAS_MAC_SHA256 = "hkdf-hmac-sha256"
@@ -95,13 +88,13 @@ internal abstract class SASVerificationTransaction(
 
     private var olmSas: OlmSAS? = null
 
-    var startReq: KeyVerificationStart? = null
-    var accepted: KeyVerificationAccept? = null
+    var startReq: VerifInfoStart? = null
+    var accepted: VerifInfoAccept? = null
     var otherKey: String? = null
     var shortCodeBytes: ByteArray? = null
 
-    var myMac: KeyVerificationMac? = null
-    var theirMac: KeyVerificationMac? = null
+    var myMac: VerifInfoMac? = null
+    var theirMac: VerifInfoMac? = null
 
     fun getSAS(): OlmSAS {
         if (olmSas == null) olmSas = OlmSAS()
@@ -160,7 +153,7 @@ internal abstract class SASVerificationTransaction(
             return
         }
 
-        val macMsg = KeyVerificationMac.create(transactionId, mapOf(keyId to macString), keyStrings)
+        val macMsg = transport.createMac(transactionId, mapOf(keyId to macString), keyStrings)
         myMac = macMsg
         state = SasVerificationTxState.SendingMac
         sendToOther(EventType.KEY_VERIFICATION_MAC, macMsg, SasVerificationTxState.MacSent, CancelCode.User) {
@@ -176,25 +169,25 @@ internal abstract class SASVerificationTransaction(
         } // if not wait for it
     }
 
-    override fun acceptToDeviceEvent(senderId: String, event: SendToDeviceObject) {
-        when (event) {
-            is KeyVerificationStart  -> onVerificationStart(event)
-            is KeyVerificationAccept -> onVerificationAccept(event)
-            is KeyVerificationKey    -> onKeyVerificationKey(senderId, event)
-            is KeyVerificationMac    -> onKeyVerificationMac(event)
-            else                     -> {
+    override fun acceptVerificationEvent(senderId: String, info: VerificationInfo) {
+        when (info) {
+            is VerifInfoStart  -> onVerificationStart(info)
+            is VerifInfoAccept -> onVerificationAccept(info)
+            is VerifInfoKey    -> onKeyVerificationKey(senderId, info)
+            is VerifInfoMac    -> onKeyVerificationMac(info)
+            else               -> {
                 // nop
             }
         }
     }
 
-    abstract fun onVerificationStart(startReq: KeyVerificationStart)
+    abstract fun onVerificationStart(startReq: VerifInfoStart)
 
-    abstract fun onVerificationAccept(accept: KeyVerificationAccept)
+    abstract fun onVerificationAccept(accept: VerifInfoAccept)
 
-    abstract fun onKeyVerificationKey(userId: String, vKey: KeyVerificationKey)
+    abstract fun onKeyVerificationKey(userId: String, vKey: VerifInfoKey)
 
-    abstract fun onKeyVerificationMac(vKey: KeyVerificationMac)
+    abstract fun onKeyVerificationMac(vKey: VerifInfoMac)
 
     protected fun verifyMacs() {
         Timber.v("## SAS verifying macs for id:$transactionId")
@@ -245,7 +238,7 @@ internal abstract class SASVerificationTransaction(
         // if none of the keys could be verified, then error because the app
         // should be informed about that
         if (verifiedDevices.isEmpty()) {
-            Timber.e("Verification: No devices verified")
+            Timber.e("## SAS Verification: No devices verified")
             cancel(CancelCode.MismatchedKeys)
             return
         }
@@ -254,6 +247,7 @@ internal abstract class SASVerificationTransaction(
         verifiedDevices.forEach {
             setDeviceVerified(it, otherUserId)
         }
+        transport.done(transactionId)
         state = SasVerificationTxState.Verified
     }
 
@@ -270,41 +264,15 @@ internal abstract class SASVerificationTransaction(
     override fun cancel(code: CancelCode) {
         cancelledReason = code
         state = SasVerificationTxState.Cancelled
-        sasVerificationService.cancelTransaction(
-                transactionId,
-                otherUserId,
-                otherDeviceId ?: "",
-                code)
+        transport.cancelTransaction(transactionId, otherUserId, otherDeviceId ?: "", code)
     }
 
     protected fun sendToOther(type: String,
-                              keyToDevice: Any,
+                              keyToDevice: VerificationInfo,
                               nextState: SasVerificationTxState,
                               onErrorReason: CancelCode,
                               onDone: (() -> Unit)?) {
-        val contentMap = MXUsersDevicesMap<Any>()
-        contentMap.setObject(otherUserId, otherDeviceId, keyToDevice)
-
-        sendToDeviceTask
-                .configureWith(SendToDeviceTask.Params(type, contentMap, transactionId)) {
-                    this.callback = object : MatrixCallback<Unit> {
-                        override fun onSuccess(data: Unit) {
-                            Timber.v("## SAS verification [$transactionId] toDevice type '$type' success.")
-                            if (onDone != null) {
-                                onDone()
-                            } else {
-                                state = nextState
-                            }
-                        }
-
-                        override fun onFailure(failure: Throwable) {
-                            Timber.e("## SAS verification [$transactionId] failed to send toDevice in state : $state")
-
-                            cancel(onErrorReason)
-                        }
-                    }
-                }
-                .executeBy(taskExecutor)
+        transport.sendToOther(type, keyToDevice, nextState, onErrorReason, onDone)
     }
 
     fun getShortCodeRepresentation(shortAuthenticationStringMode: String): String? {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransport.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransport.kt
new file mode 100644
index 0000000000..23ebd89f7a
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransport.kt
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+import im.vector.matrix.android.api.session.crypto.sas.CancelCode
+import im.vector.matrix.android.api.session.crypto.sas.SasVerificationTxState
+
+/**
+ * SAS verification can be performed using toDevice events or via DM.
+ * This class abstracts the concept of transport for SAS
+ */
+internal interface SasTransport {
+
+    /**
+     * Sends a message
+     */
+    fun sendToOther(type: String,
+                    verificationInfo: VerificationInfo,
+                    nextState: SasVerificationTxState,
+                    onErrorReason: CancelCode,
+                    onDone: (() -> Unit)?)
+
+    fun cancelTransaction(transactionId: String, userId: String, userDevice: String, code: CancelCode)
+
+    fun done(transactionId: String)
+    /**
+     * Creates an accept message suitable for this transport
+     */
+    fun createAccept(tid: String,
+                     keyAgreementProtocol: String,
+                     hash: String,
+                     commitment: String,
+                     messageAuthenticationCode: String,
+                     shortAuthenticationStrings: List<String>): VerifInfoAccept
+
+    fun createKey(tid: String,
+                     pubKey: String): VerifInfoKey
+
+    fun createMac(tid: String, mac: Map<String, String>, keys: String): VerifInfoMac
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransportRoomMessage.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransportRoomMessage.kt
new file mode 100644
index 0000000000..1173914ba1
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransportRoomMessage.kt
@@ -0,0 +1,129 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+import im.vector.matrix.android.api.MatrixCallback
+import im.vector.matrix.android.api.session.crypto.CryptoService
+import im.vector.matrix.android.api.session.crypto.sas.CancelCode
+import im.vector.matrix.android.api.session.crypto.sas.SasVerificationTxState
+import im.vector.matrix.android.api.session.events.model.EventType
+import im.vector.matrix.android.api.session.events.model.RelationType
+import im.vector.matrix.android.api.session.events.model.toContent
+import im.vector.matrix.android.api.session.room.model.message.*
+import im.vector.matrix.android.api.session.room.model.relation.RelationDefaultContent
+import im.vector.matrix.android.internal.crypto.tasks.DefaultSendVerificationMessageTask
+import im.vector.matrix.android.internal.crypto.tasks.SendVerificationMessageTask
+import im.vector.matrix.android.internal.session.room.send.SendResponse
+import im.vector.matrix.android.internal.task.TaskConstraints
+import im.vector.matrix.android.internal.task.TaskExecutor
+import im.vector.matrix.android.internal.task.configureWith
+import timber.log.Timber
+import javax.inject.Inject
+
+internal class SasTransportRoomMessage constructor(
+        private val roomId: String,
+        private val cryptoService: CryptoService,
+//        private val tx: SASVerificationTransaction?,
+        private val sendVerificationMessageTask: SendVerificationMessageTask,
+        private val taskExecutor: TaskExecutor
+) : SasTransport {
+
+    override fun sendToOther(type: String, verificationInfo: VerificationInfo, nextState: SasVerificationTxState, onErrorReason: CancelCode, onDone: (() -> Unit)?) {
+        Timber.d("## SAS sending msg type $type")
+        Timber.v("## SAS sending msg info $verificationInfo")
+        sendVerificationMessageTask.configureWith(
+                SendVerificationMessageTask.Params(
+                        type,
+                        roomId,
+                        verificationInfo.toEventContent()!!,
+                        cryptoService
+                )
+        ) {
+            constraints = TaskConstraints(true)
+            retryCount = 3
+        }
+                .executeBy(taskExecutor)
+    }
+
+    override fun cancelTransaction(transactionId: String, userId: String, userDevice: String, code: CancelCode) {
+        Timber.d("## SAS canceling transaction $transactionId for reason $code")
+        sendVerificationMessageTask.configureWith(
+                SendVerificationMessageTask.Params(
+                        EventType.KEY_VERIFICATION_CANCEL,
+                        roomId,
+                        MessageVerificationCancelContent.create(transactionId, code).toContent(),
+                        cryptoService
+                )
+        ) {
+            constraints = TaskConstraints(true)
+            retryCount = 3
+            callback = object : MatrixCallback<SendResponse> {
+                override fun onSuccess(data: SendResponse) {
+                    Timber.v("## SAS verification [$transactionId] canceled for reason ${code.value}")
+                }
+
+                override fun onFailure(failure: Throwable) {
+                    Timber.e(failure, "## SAS verification [$transactionId] failed to cancel.")
+                }
+            }
+        }
+                .executeBy(taskExecutor)
+    }
+
+    override fun done(transactionId: String) {
+        sendVerificationMessageTask.configureWith(
+                SendVerificationMessageTask.Params(
+                        EventType.KEY_VERIFICATION_DONE,
+                        roomId,
+                        MessageVerificationDoneContent(
+                                relatesTo = RelationDefaultContent(
+                                        RelationType.REFERENCE,
+                                        transactionId
+                                )
+                        ).toContent(),
+                        cryptoService
+                )
+        ) {
+            constraints = TaskConstraints(true)
+            retryCount = 3
+        }
+                .executeBy(taskExecutor)
+    }
+
+    override fun createAccept(tid: String,
+                              keyAgreementProtocol: String,
+                              hash: String,
+                              commitment: String,
+                              messageAuthenticationCode: String,
+                              shortAuthenticationStrings: List<String>)
+            : VerifInfoAccept = MessageVerificationAcceptContent.create(tid, keyAgreementProtocol, hash, commitment, messageAuthenticationCode, shortAuthenticationStrings)
+
+    override fun createKey(tid: String, pubKey: String): VerifInfoKey = MessageVerificationKeyContent.create(tid, pubKey)
+
+    override fun createMac(tid: String, mac: Map<String, String>, keys: String) = MessageVerificationMacContent.create(tid, mac, keys)
+}
+
+internal class SasTransportRoomMessageFactory @Inject constructor(
+        private val sendVerificationMessageTask: DefaultSendVerificationMessageTask,
+        private val taskExecutor: TaskExecutor) {
+
+    fun createTransport(roomId: String,
+                        cryptoService: CryptoService
+//                        tx: SASVerificationTransaction?
+    ): SasTransportRoomMessage {
+        return SasTransportRoomMessage(roomId, cryptoService, /*tx,*/ sendVerificationMessageTask, taskExecutor)
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransportToDevice.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransportToDevice.kt
new file mode 100644
index 0000000000..4f36a5218e
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/SasTransportToDevice.kt
@@ -0,0 +1,115 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+import im.vector.matrix.android.api.MatrixCallback
+import im.vector.matrix.android.api.session.crypto.sas.CancelCode
+import im.vector.matrix.android.api.session.crypto.sas.SasVerificationTxState
+import im.vector.matrix.android.api.session.events.model.EventType
+import im.vector.matrix.android.internal.crypto.model.MXUsersDevicesMap
+import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationAccept
+import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationCancel
+import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationKey
+import im.vector.matrix.android.internal.crypto.model.rest.KeyVerificationMac
+import im.vector.matrix.android.internal.crypto.tasks.SendToDeviceTask
+import im.vector.matrix.android.internal.task.TaskExecutor
+import im.vector.matrix.android.internal.task.configureWith
+import timber.log.Timber
+import javax.inject.Inject
+
+internal class SasTransportToDevice(
+        private var tx: SASVerificationTransaction?,
+        private var sendToDeviceTask: SendToDeviceTask,
+        private var taskExecutor: TaskExecutor
+) : SasTransport {
+
+    override fun sendToOther(type: String, verificationInfo: VerificationInfo, nextState: SasVerificationTxState, onErrorReason: CancelCode, onDone: (() -> Unit)?) {
+        Timber.d("## SAS sending msg type $type")
+        Timber.v("## SAS sending msg info $verificationInfo")
+        val tx = tx ?: return
+        val contentMap = MXUsersDevicesMap<Any>()
+        val toSendToDeviceObject = verificationInfo.toSendToDeviceObject()
+                ?: return Unit.also { tx.cancel() }
+
+        contentMap.setObject(tx.otherUserId, tx.otherDeviceId, toSendToDeviceObject)
+
+        sendToDeviceTask
+                .configureWith(SendToDeviceTask.Params(type, contentMap, tx.transactionId)) {
+                    this.callback = object : MatrixCallback<Unit> {
+                        override fun onSuccess(data: Unit) {
+                            Timber.v("## SAS verification [$tx.transactionId] toDevice type '$type' success.")
+                            if (onDone != null) {
+                                onDone()
+                            } else {
+                                tx.state = nextState
+                            }
+                        }
+
+                        override fun onFailure(failure: Throwable) {
+                            Timber.e("## SAS verification [$tx.transactionId] failed to send toDevice in state : $tx.state")
+
+                            tx.cancel(onErrorReason)
+                        }
+                    }
+                }
+                .executeBy(taskExecutor)
+    }
+
+    override fun done(transactionId: String) {
+        // To device do not do anything here
+    }
+
+    override fun cancelTransaction(transactionId: String, userId: String, userDevice: String, code: CancelCode) {
+        Timber.d("## SAS canceling transaction $transactionId for reason $code")
+        val cancelMessage = KeyVerificationCancel.create(transactionId, code)
+        val contentMap = MXUsersDevicesMap<Any>()
+        contentMap.setObject(userId, userDevice, cancelMessage)
+        sendToDeviceTask
+                .configureWith(SendToDeviceTask.Params(EventType.KEY_VERIFICATION_CANCEL, contentMap, transactionId)) {
+                    this.callback = object : MatrixCallback<Unit> {
+                        override fun onSuccess(data: Unit) {
+                            Timber.v("## SAS verification [$transactionId] canceled for reason ${code.value}")
+                        }
+
+                        override fun onFailure(failure: Throwable) {
+                            Timber.e(failure, "## SAS verification [$transactionId] failed to cancel.")
+                        }
+                    }
+                }
+                .executeBy(taskExecutor)
+    }
+
+    override fun createAccept(tid: String,
+                              keyAgreementProtocol: String,
+                              hash: String,
+                              commitment: String,
+                              messageAuthenticationCode: String,
+                              shortAuthenticationStrings: List<String>)
+            : VerifInfoAccept = KeyVerificationAccept.create(tid, keyAgreementProtocol, hash, commitment, messageAuthenticationCode, shortAuthenticationStrings)
+
+    override fun createKey(tid: String, pubKey: String): VerifInfoKey = KeyVerificationKey.create(tid, pubKey)
+
+    override fun createMac(tid: String, mac: Map<String, String>, keys: String) = KeyVerificationMac.create(tid, mac, keys)
+}
+
+internal class SasToDeviceTransportFactory @Inject constructor(
+        private val sendToDeviceTask: SendToDeviceTask,
+        private val taskExecutor: TaskExecutor) {
+
+    fun createTransport(tx: SASVerificationTransaction?): SasTransportToDevice {
+        return SasTransportToDevice(tx, sendToDeviceTask, taskExecutor)
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoAccept.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoAccept.kt
new file mode 100644
index 0000000000..c0677439f4
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoAccept.kt
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+internal interface VerifInfoAccept : VerificationInfo {
+
+    val transactionID: String?
+
+    /**
+     * The key agreement protocol that Bob’s device has selected to use, out of the list proposed by Alice’s device
+     */
+    val keyAgreementProtocol: String?
+
+    /**
+     * The hash algorithm that Bob’s device has selected to use, out of the list proposed by Alice’s device
+     */
+    val hash: String?
+
+    /**
+     * The message authentication code that Bob’s device has selected to use, out of the list proposed by Alice’s device
+     */
+    val messageAuthenticationCode: String?
+
+    /**
+     * An array of short authentication string methods that Bob’s client (and Bob) understands.  Must be a subset of the list proposed by Alice’s device
+     */
+    val shortAuthenticationStrings: List<String>?
+
+    /**
+     * The hash (encoded as unpadded base64) of the concatenation of the device’s ephemeral public key (QB, encoded as unpadded base64)
+     *  and the canonical JSON representation of the m.key.verification.start message.
+     */
+    var commitment: String?
+}
+
+internal interface AcceptVerifInfoFactory {
+
+    fun create(tid: String,
+               keyAgreementProtocol: String,
+               hash: String,
+               commitment: String,
+               messageAuthenticationCode: String,
+               shortAuthenticationStrings: List<String>): VerifInfoAccept
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoCancel.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoCancel.kt
new file mode 100644
index 0000000000..94c52f61ea
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoCancel.kt
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+interface VerifInfoCancel : VerificationInfo {
+
+    val transactionID: String?
+    /**
+     * machine-readable reason for cancelling, see #CancelCode
+     */
+    val code: String?
+
+    /**
+     * human-readable reason for cancelling.  This should only be used if the receiving client does not understand the code given.
+     */
+    val reason: String?
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoKey.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoKey.kt
new file mode 100644
index 0000000000..69ae917938
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoKey.kt
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+/**
+ * Sent by both devices to send their ephemeral Curve25519 public key to the other device.
+ */
+internal interface VerifInfoKey : VerificationInfo {
+
+    val transactionID: String?
+    /**
+     * The device’s ephemeral public key, as an unpadded base64 string
+     */
+    val key: String?
+}
+
+internal interface KeyVerifInfoFactory {
+    fun create(tid: String, pubKey: String): VerifInfoKey
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoMac.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoMac.kt
new file mode 100644
index 0000000000..14da21a398
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoMac.kt
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+internal interface VerifInfoMac : VerificationInfo {
+
+    val transactionID: String?
+
+    /**
+     * A map of key ID to the MAC of the key, as an unpadded base64 string, calculated using the MAC key
+     */
+    val mac: Map<String, String>?
+
+    /**
+     *  The MAC of the comma-separated, sorted list of key IDs given in the mac property,
+     *  as an unpadded base64 string, calculated using the MAC key.
+     *  For example, if the mac property gives MACs for the keys ed25519:ABCDEFG and ed25519:HIJKLMN, then this property will
+     *  give the MAC of the string “ed25519:ABCDEFG,ed25519:HIJKLMN”.
+     */
+    val keys: String?
+}
+
+internal interface VerifInfoMacFactory {
+    fun create(tid: String, mac: Map<String, String>, keys: String) : VerifInfoMac
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoStart.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoStart.kt
new file mode 100644
index 0000000000..380022def7
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerifInfoStart.kt
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+interface VerifInfoStart : VerificationInfo {
+
+    val method: String?
+    val fromDevice: String?
+
+    val transactionID: String?
+
+    val keyAgreementProtocols: List<String>?
+
+    /**
+     * An array of hashes that Alice’s client understands.
+     * Must include “sha256”.  Other methods may be defined in the future.
+     */
+    val hashes: List<String>?
+
+    /**
+     * An array of message authentication codes that Alice’s client understands.
+     * Must include “hkdf-hmac-sha256”.
+     * Other methods may be defined in the future.
+     */
+    val messageAuthenticationCodes: List<String>?
+
+    /**
+     * An array of short authentication string methods that Alice’s client (and Alice) understands.
+     * Must include “decimal”.
+     * This document also describes the “emoji” method.
+     * Other methods may be defined in the future
+     */
+    val shortAuthenticationStrings: List<String>?
+
+    fun toCanonicalJson(): String?
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationInfo.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationInfo.kt
new file mode 100644
index 0000000000..5fe5c62edd
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationInfo.kt
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+import im.vector.matrix.android.api.session.events.model.Content
+import im.vector.matrix.android.internal.crypto.model.rest.SendToDeviceObject
+
+interface VerificationInfo {
+    fun toEventContent(): Content? = null
+    fun toSendToDeviceObject(): SendToDeviceObject? = null
+    fun isValid() : Boolean
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationMessageLiveObserver.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationMessageLiveObserver.kt
new file mode 100644
index 0000000000..2886d78d8c
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationMessageLiveObserver.kt
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2019 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package im.vector.matrix.android.internal.crypto.verification
+
+import com.zhuinden.monarchy.Monarchy
+import im.vector.matrix.android.api.session.crypto.CryptoService
+import im.vector.matrix.android.api.session.crypto.MXCryptoError
+import im.vector.matrix.android.api.session.events.model.EventType
+import im.vector.matrix.android.api.session.events.model.toModel
+import im.vector.matrix.android.api.session.room.model.message.MessageContent
+import im.vector.matrix.android.api.session.room.model.message.MessageType
+import im.vector.matrix.android.internal.crypto.algorithms.olm.OlmDecryptionResult
+import im.vector.matrix.android.internal.database.RealmLiveEntityObserver
+import im.vector.matrix.android.internal.database.mapper.asDomain
+import im.vector.matrix.android.internal.database.model.EventEntity
+import im.vector.matrix.android.internal.database.query.types
+import im.vector.matrix.android.internal.di.SessionDatabase
+import im.vector.matrix.android.internal.di.UserId
+import im.vector.matrix.android.internal.task.TaskExecutor
+import io.realm.OrderedCollectionChangeSet
+import io.realm.RealmConfiguration
+import io.realm.RealmResults
+import timber.log.Timber
+import java.util.*
+import javax.inject.Inject
+
+internal class VerificationMessageLiveObserver @Inject constructor(@SessionDatabase realmConfiguration: RealmConfiguration,
+                                                                   @UserId private val userId: String,
+                                                                   private val cryptoService: CryptoService,
+                                                                   private val sasVerificationService: DefaultSasVerificationService,
+                                                                   private val taskExecutor: TaskExecutor) :
+        RealmLiveEntityObserver<EventEntity>(realmConfiguration) {
+
+    override val query = Monarchy.Query<EventEntity> {
+        EventEntity.types(it, listOf(
+                EventType.KEY_VERIFICATION_START,
+                EventType.KEY_VERIFICATION_ACCEPT,
+                EventType.KEY_VERIFICATION_KEY,
+                EventType.KEY_VERIFICATION_MAC,
+                EventType.KEY_VERIFICATION_CANCEL,
+                EventType.KEY_VERIFICATION_DONE,
+                EventType.MESSAGE,
+                EventType.ENCRYPTED)
+        )
+    }
+
+    override fun onChange(results: RealmResults<EventEntity>, changeSet: OrderedCollectionChangeSet) {
+        // TODO do that in a task
+        // TODO how to ignore when it's an initial sync?
+        val events = changeSet.insertions
+                .asSequence()
+                .mapNotNull { results[it]?.asDomain() }
+                .filterNot {
+                    // ignore mines ^^
+                    it.senderId == userId
+                }
+                .toList()
+
+        events.forEach { event ->
+            Timber.d("## SAS Verification live observer: received msgId: ${event.eventId}   msgtype: ${event.type} from ${event.senderId}")
+            Timber.v("## SAS Verification live observer: received msgId: $event")
+
+            // decrypt if needed?
+
+            if (event.isEncrypted() && event.mxDecryptionResult == null) {
+                // TODO use a global event decryptor? attache to session and that listen to new sessionId?
+                // for now decrypt sync
+                try {
+                    val result = cryptoService.decryptEvent(event, event.roomId + UUID.randomUUID().toString())
+                    event.mxDecryptionResult = OlmDecryptionResult(
+                            payload = result.clearEvent,
+                            senderKey = result.senderCurve25519Key,
+                            keysClaimed = result.claimedEd25519Key?.let { mapOf("ed25519" to it) },
+                            forwardingCurve25519KeyChain = result.forwardingCurve25519KeyChain
+                    )
+                } catch (e: MXCryptoError) {
+                    Timber.e("## SAS Failed to decrypt event: ${event.eventId}")
+                }
+            }
+            Timber.v("## SAS Verification live observer: received msgId: ${event.eventId} type: ${event.getClearType()}")
+            when (event.getClearType()) {
+                EventType.KEY_VERIFICATION_START,
+                EventType.KEY_VERIFICATION_ACCEPT,
+                EventType.KEY_VERIFICATION_KEY,
+                EventType.KEY_VERIFICATION_MAC,
+                EventType.KEY_VERIFICATION_CANCEL,
+                EventType.KEY_VERIFICATION_DONE -> {
+                    sasVerificationService.onRoomEvent(event)
+                }
+                EventType.MESSAGE               -> {
+                    if (MessageType.MSGTYPE_VERIFICATION_REQUEST == event.getClearContent().toModel<MessageContent>()?.type) {
+                        // TODO  If the request is in the future by more than 5 minutes or more than 10 minutes in the past,
+                        // the message should be ignored by the receiver.
+                        sasVerificationService.onRoomRequestReceived(event)
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationTransaction.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationTransaction.kt
index be3f4c7885..d6cc5e3279 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationTransaction.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/VerificationTransaction.kt
@@ -17,7 +17,6 @@ package im.vector.matrix.android.internal.crypto.verification
 
 import im.vector.matrix.android.api.session.crypto.sas.CancelCode
 import im.vector.matrix.android.api.session.crypto.sas.SasVerificationTransaction
-import im.vector.matrix.android.internal.crypto.model.rest.SendToDeviceObject
 
 /**
  * Generic interactive key verification transaction
@@ -42,7 +41,7 @@ internal abstract class VerificationTransaction(
         listeners.remove(listener)
     }
 
-    abstract fun acceptToDeviceEvent(senderId: String, event: SendToDeviceObject)
+    abstract fun acceptVerificationEvent(senderId: String, info: VerificationInfo)
 
     abstract fun cancel(code: CancelCode)
 }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/RetrofitExtensions.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/RetrofitExtensions.kt
index fa0b9a1f1c..a89e21b04a 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/RetrofitExtensions.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/RetrofitExtensions.kt
@@ -104,7 +104,7 @@ private fun toFailure(errorBody: ResponseBody?, httpCode: Int): Failure {
 
             return Failure.ServerError(matrixError, httpCode)
         }
-    } catch (ex: JsonDataException) {
+    } catch (ex: Exception) {
         // This is not a MatrixError
         Timber.w("The error returned by the server is not a MatrixError")
     } catch (ex: JsonEncodingException) {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/SessionModule.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/SessionModule.kt
index 0e88894969..b7d121998c 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/SessionModule.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/SessionModule.kt
@@ -30,6 +30,7 @@ import im.vector.matrix.android.api.session.InitialSyncProgressService
 import im.vector.matrix.android.api.session.Session
 import im.vector.matrix.android.api.session.homeserver.HomeServerCapabilitiesService
 import im.vector.matrix.android.api.session.securestorage.SecureStorageService
+import im.vector.matrix.android.internal.crypto.verification.VerificationMessageLiveObserver
 import im.vector.matrix.android.internal.database.LiveEntityObserver
 import im.vector.matrix.android.internal.database.SessionRealmConfigurationFactory
 import im.vector.matrix.android.internal.di.*
@@ -164,6 +165,10 @@ internal abstract class SessionModule {
     @IntoSet
     abstract fun bindRoomCreateEventLiveObserver(roomCreateEventLiveObserver: RoomCreateEventLiveObserver): LiveEntityObserver
 
+    @Binds
+    @IntoSet
+    abstract fun bindVerificationEventObserver(verificationMessageLiveObserver: VerificationMessageLiveObserver): LiveEntityObserver
+
     @Binds
     abstract fun bindInitialSyncProgressService(initialSyncProgressService: DefaultInitialSyncProgressService): InitialSyncProgressService
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt
index 8fad03b588..acbe385ff6 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt
@@ -157,7 +157,8 @@ internal class DefaultSendService @AssistedInject constructor(@Assisted private
 
     override fun deleteFailedEcho(localEcho: TimelineEvent) {
         monarchy.writeAsync { realm ->
-            TimelineEventEntity.where(realm, roomId = roomId, eventId = localEcho.root.eventId ?: "").findFirst()?.let {
+            TimelineEventEntity.where(realm, roomId = roomId, eventId = localEcho.root.eventId
+                    ?: "").findFirst()?.let {
                 it.deleteFromRealm()
             }
             EventEntity.where(realm, eventId = localEcho.root.eventId ?: "").findFirst()?.let {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt
index 0fed1ca6f5..a225146d83 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt
@@ -286,6 +286,24 @@ internal class LocalEchoEventFactory @Inject constructor(
         )
     }
 
+    fun createVerificationRequest(roomId: String, fromDevice: String, to: String, methods: List<String>): Event {
+        val localID = LocalEcho.createLocalEchoId()
+        return Event(
+                roomId = roomId,
+                originServerTs = dummyOriginServerTs(),
+                senderId = userId,
+                eventId = localID,
+                type = EventType.MESSAGE,
+                content = MessageVerificationRequestContent(
+                        body = stringProvider.getString(R.string.key_verification_request_fallback_message, userId),
+                        fromDevice = fromDevice,
+                        to = to,
+                        methods = methods
+                ).toContent(),
+                unsignedData = UnsignedData(age = null, transactionId = localID)
+        )
+    }
+
     private fun dummyOriginServerTs(): Long {
         return System.currentTimeMillis()
     }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoUpdater.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoUpdater.kt
index 4c45ba0a4d..d6d924ab46 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoUpdater.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoUpdater.kt
@@ -20,7 +20,6 @@ import com.zhuinden.monarchy.Monarchy
 import im.vector.matrix.android.api.session.room.send.SendState
 import im.vector.matrix.android.internal.database.model.EventEntity
 import im.vector.matrix.android.internal.database.query.where
-import im.vector.matrix.android.internal.util.awaitTransaction
 import timber.log.Timber
 import javax.inject.Inject
 
@@ -28,7 +27,7 @@ internal class LocalEchoUpdater @Inject constructor(private val monarchy: Monarc
 
     suspend fun updateSendState(eventId: String, sendState: SendState) {
         Timber.v("Update local state of $eventId to ${sendState.name}")
-        monarchy.awaitTransaction { realm ->
+        monarchy.writeAsync { realm ->
             val sendingEventEntity = EventEntity.where(realm, eventId).findFirst()
             if (sendingEventEntity != null) {
                 if (sendState == SendState.SENT && sendingEventEntity.sendState == SendState.SYNCED) {
diff --git a/matrix-sdk-android/src/main/res/values/strings_RiotX.xml b/matrix-sdk-android/src/main/res/values/strings_RiotX.xml
index a22533c6d1..4fe6009268 100644
--- a/matrix-sdk-android/src/main/res/values/strings_RiotX.xml
+++ b/matrix-sdk-android/src/main/res/values/strings_RiotX.xml
@@ -17,4 +17,7 @@
     <string name="notice_room_withdraw_with_reason">%1$s withdrew %2$s\'s invitation. Reason: %3$s</string>
 
     <string name="no_network_indicator">There is no network connection right now</string>
+
+    <string name="key_verification_request_fallback_message">%s is requesting to verify your key, but your client does not support in-chat key verification. You will need to use legacy key verification to verify keys.</string>
+
 </resources>
\ No newline at end of file
diff --git a/vector/src/main/java/im/vector/riotx/core/di/FragmentModule.kt b/vector/src/main/java/im/vector/riotx/core/di/FragmentModule.kt
index 442c5f6f96..94d7a39379 100644
--- a/vector/src/main/java/im/vector/riotx/core/di/FragmentModule.kt
+++ b/vector/src/main/java/im/vector/riotx/core/di/FragmentModule.kt
@@ -207,6 +207,11 @@ interface FragmentModule {
     @FragmentKey(VectorSettingsNotificationPreferenceFragment::class)
     fun bindVectorSettingsNotificationPreferenceFragment(fragment: VectorSettingsNotificationPreferenceFragment): Fragment
 
+    @Binds
+    @IntoMap
+    @FragmentKey(VectorSettingsLabsFragment::class)
+    fun bindVectorSettingsLabsFragment(fragment: VectorSettingsLabsFragment): Fragment
+
     @Binds
     @IntoMap
     @FragmentKey(VectorSettingsPreferencesFragment::class)
diff --git a/vector/src/main/java/im/vector/riotx/features/command/Command.kt b/vector/src/main/java/im/vector/riotx/features/command/Command.kt
index 8b72ffa4a6..fbc3ddebe5 100644
--- a/vector/src/main/java/im/vector/riotx/features/command/Command.kt
+++ b/vector/src/main/java/im/vector/riotx/features/command/Command.kt
@@ -38,7 +38,9 @@ enum class Command(val command: String, val parameters: String, @StringRes val d
     CHANGE_DISPLAY_NAME("/nick", "<display-name>", R.string.command_description_nick),
     MARKDOWN("/markdown", "<on|off>", R.string.command_description_markdown),
     CLEAR_SCALAR_TOKEN("/clear_scalar_token", "", R.string.command_description_clear_scalar_token),
-    SPOILER("/spoiler", "<message>", R.string.command_description_spoiler);
+    SHRUG("/shrug", "<message>", R.string.command_description_shrug),
+    // TODO temporary command
+    VERIFY_USER("/verify", "<userID>", R.string.command_description_spoiler);
 
     val length
         get() = command.length + 1
diff --git a/vector/src/main/java/im/vector/riotx/features/command/CommandParser.kt b/vector/src/main/java/im/vector/riotx/features/command/CommandParser.kt
index 359f2c1f13..23e30e1d3c 100644
--- a/vector/src/main/java/im/vector/riotx/features/command/CommandParser.kt
+++ b/vector/src/main/java/im/vector/riotx/features/command/CommandParser.kt
@@ -244,6 +244,17 @@ object CommandParser {
 
                     ParsedCommand.SendSpoiler(message)
                 }
+                Command.SHRUG.command                -> {
+                    val message = textMessage.subSequence(Command.SHRUG.command.length, textMessage.length).trim()
+
+                    ParsedCommand.SendShrug(message)
+                }
+
+                Command.VERIFY_USER.command                -> {
+                    val message = textMessage.substring(Command.VERIFY_USER.command.length).trim()
+
+                    ParsedCommand.VerifyUser(message)
+                }
                 else                                   -> {
                     // Unknown command
                     ParsedCommand.ErrorUnknownSlashCommand(slashCommand)
diff --git a/vector/src/main/java/im/vector/riotx/features/command/ParsedCommand.kt b/vector/src/main/java/im/vector/riotx/features/command/ParsedCommand.kt
index dd7c0c7e86..b16f68c7b9 100644
--- a/vector/src/main/java/im/vector/riotx/features/command/ParsedCommand.kt
+++ b/vector/src/main/java/im/vector/riotx/features/command/ParsedCommand.kt
@@ -46,4 +46,6 @@ sealed class ParsedCommand {
     class SetMarkdown(val enable: Boolean) : ParsedCommand()
     object ClearScalarToken : ParsedCommand()
     class SendSpoiler(val message: String) : ParsedCommand()
+    class SendShrug(val message: CharSequence) : ParsedCommand()
+    class VerifyUser(val userId: String) : ParsedCommand()
 }
diff --git a/vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailViewModel.kt b/vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailViewModel.kt
index e7a18753cd..efdfd53234 100644
--- a/vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailViewModel.kt
+++ b/vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailViewModel.kt
@@ -50,7 +50,6 @@ import im.vector.matrix.android.internal.crypto.attachments.toElementToDecrypt
 import im.vector.matrix.android.internal.crypto.model.event.EncryptedEventContent
 import im.vector.matrix.rx.rx
 import im.vector.matrix.rx.unwrap
-import im.vector.riotx.BuildConfig
 import im.vector.riotx.R
 import im.vector.riotx.core.extensions.postLiveEvent
 import im.vector.riotx.core.platform.VectorViewModel
@@ -377,6 +376,25 @@ class RoomDetailViewModel @AssistedInject constructor(@Assisted initialState: Ro
                             _sendMessageResultLiveData.postLiveEvent(SendMessageResult.SlashCommandHandled())
                             popDraft()
                         }
+                        is ParsedCommand.SendShrug                -> {
+                            val sequence: CharSequence = buildString {
+                                append("¯\\_(ツ)_/¯")
+                                        .apply {
+                                            if (slashCommandResult.message.isNotEmpty()) {
+                                                append(" ")
+                                                append(slashCommandResult.message)
+                                            }
+                                        }
+                            }
+                            room.sendTextMessage(sequence)
+                            _sendMessageResultLiveData.postLiveEvent(SendMessageResult.SlashCommandHandled())
+                            popDraft()
+                        }
+                        is ParsedCommand.VerifyUser               -> {
+                            session.getSasVerificationService().requestKeyVerificationInDMs(slashCommandResult.userId, room.roomId, null)
+                            _sendMessageResultLiveData.postLiveEvent(SendMessageResult.SlashCommandHandled())
+                            popDraft()
+                        }
                         is ParsedCommand.ChangeTopic              -> {
                             handleChangeTopicSlashCommand(slashCommandResult)
                             popDraft()
diff --git a/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/factory/TimelineItemFactory.kt b/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/factory/TimelineItemFactory.kt
index 5b6dec9900..4c36b55fef 100644
--- a/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/factory/TimelineItemFactory.kt
+++ b/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/factory/TimelineItemFactory.kt
@@ -64,6 +64,16 @@ class TimelineItemFactory @Inject constructor(private val messageItemFactory: Me
                         encryptedItemFactory.create(event, nextEvent, highlight, callback)
                     }
                 }
+                EventType.KEY_VERIFICATION_ACCEPT,
+                EventType.KEY_VERIFICATION_START,
+                EventType.KEY_VERIFICATION_DONE,
+                EventType.KEY_VERIFICATION_CANCEL,
+                EventType.KEY_VERIFICATION_KEY,
+                EventType.KEY_VERIFICATION_MAC          -> {
+                    // These events are filtered from timeline in normal case
+                    // Only visible in developer mode
+                    defaultItemFactory.create(event, highlight, readMarkerVisible, callback)
+                }
 
                 // Unhandled event types (yet)
                 EventType.STATE_ROOM_THIRD_PARTY_INVITE -> defaultItemFactory.create(event, highlight, callback)
diff --git a/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/helper/TimelineDisplayableEvents.kt b/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/helper/TimelineDisplayableEvents.kt
index 1cd851f8c8..033ff68433 100644
--- a/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/helper/TimelineDisplayableEvents.kt
+++ b/vector/src/main/java/im/vector/riotx/features/home/room/detail/timeline/helper/TimelineDisplayableEvents.kt
@@ -42,7 +42,13 @@ object TimelineDisplayableEvents {
 
     val DEBUG_DISPLAYABLE_TYPES = DISPLAYABLE_TYPES + listOf(
             EventType.REDACTION,
-            EventType.REACTION
+            EventType.REACTION,
+            EventType.KEY_VERIFICATION_ACCEPT,
+            EventType.KEY_VERIFICATION_START,
+            EventType.KEY_VERIFICATION_DONE,
+            EventType.KEY_VERIFICATION_CANCEL,
+            EventType.KEY_VERIFICATION_MAC,
+            EventType.KEY_VERIFICATION_KEY
     )
 }
 
diff --git a/vector/src/main/java/im/vector/riotx/features/settings/VectorPreferences.kt b/vector/src/main/java/im/vector/riotx/features/settings/VectorPreferences.kt
index dd99488465..ee8c0530d9 100755
--- a/vector/src/main/java/im/vector/riotx/features/settings/VectorPreferences.kt
+++ b/vector/src/main/java/im/vector/riotx/features/settings/VectorPreferences.kt
@@ -23,6 +23,7 @@ import android.net.Uri
 import android.provider.MediaStore
 import androidx.core.content.edit
 import androidx.preference.PreferenceManager
+import im.vector.riotx.BuildConfig
 import im.vector.riotx.R
 import im.vector.riotx.features.homeserver.ServerUrlsRepository
 import im.vector.riotx.features.themes.ThemeUtils
@@ -256,7 +257,7 @@ class VectorPreferences @Inject constructor(private val context: Context) {
     }
 
     fun labAllowedExtendedLogging(): Boolean {
-        return defaultPrefs.getBoolean(SETTINGS_LABS_ALLOW_EXTENDED_LOGS, false)
+        return defaultPrefs.getBoolean(SETTINGS_LABS_ALLOW_EXTENDED_LOGS, BuildConfig.DEBUG)
     }
 
     /**
diff --git a/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsLabsFragment.kt b/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsLabsFragment.kt
index 37dfd02c43..cd201900fb 100644
--- a/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsLabsFragment.kt
+++ b/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsLabsFragment.kt
@@ -17,14 +17,21 @@
 package im.vector.riotx.features.settings
 
 import im.vector.riotx.R
+import im.vector.riotx.core.preference.VectorSwitchPreference
+import javax.inject.Inject
 
-class VectorSettingsLabsFragment : VectorSettingsBaseFragment() {
+class VectorSettingsLabsFragment @Inject constructor(val vectorPreferences: VectorPreferences) : VectorSettingsBaseFragment() {
 
     override var titleRes = R.string.room_settings_labs_pref_title
     override val preferenceXmlRes = R.xml.vector_settings_labs
 
     override fun bindPref() {
         // Lab
+
+        findPreference<VectorSwitchPreference>(VectorPreferences.SETTINGS_LABS_ALLOW_EXTENDED_LOGS)?.let {
+            it.isChecked = vectorPreferences.labAllowedExtendedLogging()
+        }
+
 //        val useCryptoPref = findPreference(VectorPreferences.SETTINGS_ROOM_SETTINGS_LABS_END_TO_END_PREFERENCE_KEY) as SwitchPreference
 //        val cryptoIsEnabledPref = findPreference(VectorPreferences.SETTINGS_ROOM_SETTINGS_LABS_END_TO_END_IS_ACTIVE_PREFERENCE_KEY)
 
diff --git a/vector/src/main/res/values/strings.xml b/vector/src/main/res/values/strings.xml
index 2e4d04354b..10ca8e728e 100644
--- a/vector/src/main/res/values/strings.xml
+++ b/vector/src/main/res/values/strings.xml
@@ -1695,6 +1695,7 @@ Not all features in Riot are implemented in RiotX yet. Main missing (and coming
     <string name="room_directory_search_hint">Name or ID (#example:matrix.org)</string>
 
     <string name="labs_swipe_to_reply_in_timeline">Enable swipe to reply in timeline</string>
+    <string name="labs_enable_verification_other_dm">Enable verification other DM</string>
 
     <string name="link_copied_to_clipboard">Link copied to clipboard</string>
 
diff --git a/vector/src/main/res/values/strings_riotX.xml b/vector/src/main/res/values/strings_riotX.xml
index f259a34e44..f8d65fab15 100644
--- a/vector/src/main/res/values/strings_riotX.xml
+++ b/vector/src/main/res/values/strings_riotX.xml
@@ -12,6 +12,8 @@
     <string name="room_list_quick_actions_leave">"Leave the room"</string>
     <string name="notice_member_no_changes">"%1$s made no changes"</string>
     <string name="command_description_spoiler">Sends the given message as a spoiler</string>
+    <string name="command_description_verify">Request to verify the given userID</string>
+    <string name="command_description_shrug">Prepends ¯\\_(ツ)_/¯ to a plain-text message</string>
     <string name="spoiler">Spoiler</string>
     <string name="reaction_search_type_hint">Type keywords to find a reaction.</string>
 
diff --git a/vector/src/main/res/xml/vector_settings_labs.xml b/vector/src/main/res/xml/vector_settings_labs.xml
index e9e5e27198..1a64f75de5 100644
--- a/vector/src/main/res/xml/vector_settings_labs.xml
+++ b/vector/src/main/res/xml/vector_settings_labs.xml
@@ -45,7 +45,6 @@
         android:key="SETTINGS_LABS_ENABLE_SWIPE_TO_REPLY"
         android:title="@string/labs_swipe_to_reply_in_timeline" />
 
-
     <im.vector.riotx.core.preference.VectorSwitchPreference
         android:defaultValue="false"
         android:key="SETTINGS_LABS_ALLOW_EXTENDED_LOGS"