diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MXEncryptedAttachments.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MXEncryptedAttachments.kt
index 5672d195cc..d159bcd512 100755
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MXEncryptedAttachments.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MXEncryptedAttachments.kt
@@ -20,6 +20,9 @@ package org.matrix.android.sdk.internal.crypto.attachments
 import android.util.Base64
 import org.matrix.android.sdk.internal.crypto.model.rest.EncryptedFileInfo
 import org.matrix.android.sdk.internal.crypto.model.rest.EncryptedFileKey
+import org.matrix.android.sdk.internal.util.base64ToBase64Url
+import org.matrix.android.sdk.internal.util.base64ToUnpaddedBase64
+import org.matrix.android.sdk.internal.util.base64UrlToBase64
 import timber.log.Timber
 import java.io.ByteArrayOutputStream
 import java.io.File
@@ -310,25 +313,4 @@ internal object MXEncryptedAttachments {
 
         return false
     }
-
-    /**
-     * Base64 URL conversion methods
-     */
-
-    private fun base64UrlToBase64(base64Url: String): String {
-        return base64Url.replace('-', '+')
-                .replace('_', '/')
-    }
-
-    internal fun base64ToBase64Url(base64: String): String {
-        return base64.replace("\n".toRegex(), "")
-                .replace("\\+".toRegex(), "-")
-                .replace('/', '_')
-                .replace("=", "")
-    }
-
-    internal fun base64ToUnpaddedBase64(base64: String): String {
-        return base64.replace("\n".toRegex(), "")
-                .replace("=", "")
-    }
 }
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MatrixDigestCheckInputStream.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MatrixDigestCheckInputStream.kt
index 9ae4703e05..7ca5158f64 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MatrixDigestCheckInputStream.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/attachments/MatrixDigestCheckInputStream.kt
@@ -17,6 +17,7 @@
 package org.matrix.android.sdk.internal.crypto.attachments
 
 import android.util.Base64
+import org.matrix.android.sdk.internal.util.base64ToUnpaddedBase64
 import java.io.FilterInputStream
 import java.io.IOException
 import java.io.InputStream
@@ -60,7 +61,7 @@ class MatrixDigestCheckInputStream(
 
     @Throws(IOException::class)
     private fun ensureDigest() {
-        val currentDigestValue = MXEncryptedAttachments.base64ToUnpaddedBase64(Base64.encodeToString(digest.digest(), Base64.DEFAULT))
+        val currentDigestValue = base64ToUnpaddedBase64(Base64.encodeToString(digest.digest(), Base64.DEFAULT))
         if (currentDigestValue != expectedDigest) {
             throw IOException("Bad digest")
         }
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/identity/IdentityBulkLookupTask.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/identity/IdentityBulkLookupTask.kt
index ac33c2666f..45d7d48a18 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/identity/IdentityBulkLookupTask.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/identity/IdentityBulkLookupTask.kt
@@ -23,7 +23,6 @@ import org.matrix.android.sdk.api.session.identity.FoundThreePid
 import org.matrix.android.sdk.api.session.identity.IdentityServiceError
 import org.matrix.android.sdk.api.session.identity.ThreePid
 import org.matrix.android.sdk.api.session.identity.toMedium
-import org.matrix.android.sdk.internal.crypto.attachments.MXEncryptedAttachments.base64ToBase64Url
 import org.matrix.android.sdk.internal.crypto.tools.withOlmUtility
 import org.matrix.android.sdk.internal.di.UserId
 import org.matrix.android.sdk.internal.network.executeRequest
@@ -32,6 +31,7 @@ import org.matrix.android.sdk.internal.session.identity.model.IdentityHashDetail
 import org.matrix.android.sdk.internal.session.identity.model.IdentityLookUpParams
 import org.matrix.android.sdk.internal.session.identity.model.IdentityLookUpResponse
 import org.matrix.android.sdk.internal.task.Task
+import org.matrix.android.sdk.internal.util.base64ToBase64Url
 import java.util.Locale
 import javax.inject.Inject
 
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/Base64.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/Base64.kt
new file mode 100644
index 0000000000..76e24c4e31
--- /dev/null
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/Base64.kt
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2020 New Vector Ltd
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * 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 org.matrix.android.sdk.internal.util
+
+/**
+ * Base64 URL conversion methods
+ */
+
+internal fun base64UrlToBase64(base64Url: String): String {
+    return base64Url.replace('-', '+')
+            .replace('_', '/')
+}
+
+internal fun base64ToBase64Url(base64: String): String {
+    return base64.replace("\n".toRegex(), "")
+            .replace("\\+".toRegex(), "-")
+            .replace('/', '_')
+            .replace("=", "")
+}
+
+internal fun base64ToUnpaddedBase64(base64: String): String {
+    return base64.replace("\n".toRegex(), "")
+            .replace("=", "")
+}