diff --git a/.github/workflows/android.yml b/.github/workflows/android.yml
new file mode 100644
index 0000000..6ea8d73
--- /dev/null
+++ b/.github/workflows/android.yml
@@ -0,0 +1,30 @@
+name: Android
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Set up Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 17
+
+      - name: Set up Gradle
+        uses: gradle/actions/setup-gradle@v4
+
+      - name: Run unit tests
+        run: bash ./gradlew test
diff --git a/.github/workflows/deno.yml b/.github/workflows/deno.yml
deleted file mode 100644
index 782af35..0000000
--- a/.github/workflows/deno.yml
+++ /dev/null
@@ -1,42 +0,0 @@
-# This workflow uses actions that are not certified by GitHub.
-# They are provided by a third-party and are governed by
-# separate terms of service, privacy policy, and support
-# documentation.
-
-# This workflow will install Deno then run `deno lint` and `deno test`.
-# For more information see: https://github.com/denoland/setup-deno
-
-name: Deno
-
-on:
-  push:
-    branches: ["main"]
-  pull_request:
-    branches: ["main"]
-
-permissions:
-  contents: read
-
-jobs:
-  test:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Setup repo
-        uses: actions/checkout@v4
-
-      - name: Setup Deno
-        # uses: denoland/setup-deno@v1
-        uses: denoland/setup-deno@61fe2df320078202e33d7d5ad347e7dcfa0e8f31  # v1.1.2
-        with:
-          deno-version: v1.x
-
-      # Uncomment this step to verify the use of 'deno fmt' on each commit.
-      # - name: Verify formatting
-      #   run: deno fmt --check
-
-      - name: Run linter
-        run: deno lint
-
-      - name: Run tests
-        run: deno test -A
diff --git a/app/src/main/java/hu/regelo/app/data/EncryptedLocalDatabase.kt b/app/src/main/java/hu/regelo/app/data/EncryptedLocalDatabase.kt
index 22b133a..3673d19 100644
--- a/app/src/main/java/hu/regelo/app/data/EncryptedLocalDatabase.kt
+++ b/app/src/main/java/hu/regelo/app/data/EncryptedLocalDatabase.kt
@@ -95,6 +95,9 @@ internal object EncryptedLocalDatabase {
         } finally {
             plainDb.close()
         }
+        check(temporary.createNewFile()) {
+            "A titkosított adatbázis ideiglenes fájlja nem hozható létre."
+        }
         listOf("-wal", "-shm").forEach { suffix ->
             val sidecar = File(database.absolutePath + suffix)
             check(!sidecar.exists() || sidecar.delete()) {
@@ -103,22 +106,38 @@ internal object EncryptedLocalDatabase {
         }
 
         try {
-            database.copyTo(temporary, overwrite = true)
             val migrationDb = SQLiteDatabase.openDatabase(
-                temporary.absolutePath,
+                database.absolutePath,
                 null,
                 SQLiteDatabase.OPEN_READWRITE,
             )
             try {
                 verifyReadable(migrationDb)
-                migrationDb.changePassword(passphrase)
-                verifyReadable(migrationDb)
+                val schemaVersion = migrationDb.version
+                migrationDb.execSQL(
+                    "ATTACH DATABASE ? AS encrypted KEY ?",
+                    arrayOf(temporary.absolutePath, passphrase),
+                )
+                try {
+                    migrationDb.rawQuery("SELECT sqlcipher_export('encrypted')", null).use { cursor ->
+                        check(cursor.moveToFirst() && cursor.getInt(0) == 0) {
+                            "Az SQLite-adatbázis titkosított exportja sikertelen."
+                        }
+                    }
+                    migrationDb.execSQL("PRAGMA encrypted.user_version = $schemaVersion")
+                    migrationDb.rawQuery("PRAGMA encrypted.user_version", null).use { cursor ->
+                        check(cursor.moveToFirst() && cursor.getInt(0) == schemaVersion) {
+                            "Az adatbázis sémaverziójának exportja sikertelen."
+                        }
+                    }
+                } finally {
+                    migrationDb.execSQL("DETACH DATABASE encrypted")
+                }
             } finally {
                 migrationDb.close()
             }
             verifyEncryptedDatabase(temporary, passphrase)
             Os.rename(temporary.absolutePath, database.absolutePath)
-            verifyEncryptedDatabase(database, passphrase)
         } catch (e: Exception) {
             temporary.delete()
             throw IllegalStateException(