diff --git a/build.gradle b/build.gradle
index 625ed348be..370006d1c9 100644
--- a/build.gradle
+++ b/build.gradle
@@ -70,6 +70,7 @@ allprojects {
         // Warnings are potential errors, so stop ignoring them
         // You can override by passing `-PallWarningsAsErrors=false` in the command line
         kotlinOptions.allWarningsAsErrors = project.getProperties().getOrDefault("allWarningsAsErrors", "true").toBoolean()
+        kotlinOptions.freeCompilerArgs += "-Xopt-in=kotlin.ExperimentalUnsignedTypes"
     }
 }
 
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/DefaultCryptoService.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/DefaultCryptoService.kt
index d230008b71..257f1c9a05 100755
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/DefaultCryptoService.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/DefaultCryptoService.kt
@@ -84,6 +84,7 @@ import org.matrix.android.sdk.internal.crypto.tasks.UploadKeysTask
 import org.matrix.android.sdk.internal.crypto.verification.DefaultVerificationService
 import org.matrix.android.sdk.internal.di.DeviceId
 import org.matrix.android.sdk.internal.di.MoshiProvider
+import org.matrix.android.sdk.internal.di.SessionFilesDirectory
 import org.matrix.android.sdk.internal.di.UserId
 import org.matrix.android.sdk.internal.extensions.foldToCallback
 import org.matrix.android.sdk.internal.session.SessionScope
@@ -97,6 +98,7 @@ import org.matrix.android.sdk.internal.util.JsonCanonicalizer
 import org.matrix.android.sdk.internal.util.MatrixCoroutineDispatchers
 import org.matrix.olm.OlmManager
 import timber.log.Timber
+import java.io.File
 import java.util.concurrent.atomic.AtomicBoolean
 import javax.inject.Inject
 import kotlin.jvm.Throws
@@ -120,6 +122,8 @@ internal class DefaultCryptoService @Inject constructor(
         private val userId: String,
         @DeviceId
         private val deviceId: String?,
+        @SessionFilesDirectory
+        private val dataDir: File,
         private val myDeviceInfoHolder: Lazy<MyDeviceInfoHolder>,
         // the crypto store
         private val cryptoStore: IMXCryptoStore,
@@ -171,6 +175,7 @@ internal class DefaultCryptoService @Inject constructor(
 
     private val isStarting = AtomicBoolean(false)
     private val isStarted = AtomicBoolean(false)
+    private var olmMachine: OlmMachine? = null
 
     fun onStateEvent(roomId: String, event: Event) {
         when (event.getClearType()) {
@@ -310,7 +315,7 @@ internal class DefaultCryptoService @Inject constructor(
      * devices.
      *
      */
-    fun start() {
+    suspend fun start() {
         cryptoCoroutineScope.launch(coroutineDispatchers.crypto) {
             internalStart()
         }
@@ -363,14 +368,14 @@ internal class DefaultCryptoService @Inject constructor(
             return
         }
         isStarting.set(true)
+        Timber.v("HELLLO WORLD STARTING CRYPTO")
+
         try {
-            val dataDir = "/data/data/im.vector.app.debug/files"
-            val olmMachine = OlmMachine("@example:localhost", "DEVICEID", dataDir)
-            Timber.v("HELLLO WORLD STARTING CRYPTO ${olmMachine.identityKeys()}")
+            olmMachine = OlmMachine(userId, deviceId!!, dataDir)
+            Timber.v("HELLLO WORLD STARTING CRYPTO ${olmMachine?.identityKeys()}")
         } catch (throwable: Throwable) {
             Timber.v("HELLLO WORLD FAILED CRYPTO $throwable")
         }
-        Timber.v("HELLLO WORLD STARTING CRYPTO")
 
         // Open the store
         cryptoStore.open()
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/newCrypto.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/newCrypto.kt
index e48bc0f1f7..2e1308f4b6 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/newCrypto.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/newCrypto.kt
@@ -16,11 +16,11 @@
 
 package org.matrix.android.sdk.internal
 
-import kotlinx.coroutines.withContext
+import java.io.File
 import kotlinx.coroutines.Dispatchers
-
-import uniffi.olm.OlmMachine as InnerMachine
+import kotlinx.coroutines.withContext
 import uniffi.olm.Device as InnerDevice
+import uniffi.olm.OlmMachine as InnerMachine
 import uniffi.olm.Sas as InnerSas
 
 class Device(inner: InnerDevice, machine: InnerMachine) {
@@ -44,8 +44,8 @@ class Device(inner: InnerDevice, machine: InnerMachine) {
     }
 }
 
-class OlmMachine(user_id: String, device_id: String, path: String) {
-    private val inner: InnerMachine = InnerMachine(user_id, device_id, path)
+class OlmMachine(user_id: String, device_id: String, path: File) {
+    private val inner: InnerMachine = InnerMachine(user_id, device_id, path.toString())
 
     fun userId(): String {
         return this.inner.userId()
@@ -59,10 +59,6 @@ class OlmMachine(user_id: String, device_id: String, path: String) {
         return this.inner.identityKeys()
     }
 
-    suspend fun slowUserId(): String = withContext(Dispatchers.Default) {
-        inner.slowUserId()
-    }
-
     suspend fun getDevice(user_id: String, device_id: String): Device? = withContext(Dispatchers.IO) {
         when (val device: InnerDevice? = inner.getDevice(user_id, device_id)) {
             null -> null