diff --git a/src/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java b/src/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java
index 2dc877906d..14708f9f38 100644
--- a/src/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java
+++ b/src/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java
@@ -41,6 +41,7 @@ import org.thoughtcrime.securesms.loki.database.LokiPreKeyBundleDatabase;
 import org.thoughtcrime.securesms.loki.database.LokiPreKeyRecordDatabase;
 import org.thoughtcrime.securesms.loki.database.LokiThreadDatabase;
 import org.thoughtcrime.securesms.loki.database.LokiUserDatabase;
+import org.thoughtcrime.securesms.loki.database.SharedSenderKeysDatabase;
 import org.thoughtcrime.securesms.notifications.NotificationChannels;
 import org.thoughtcrime.securesms.service.KeyCachingService;
 import org.thoughtcrime.securesms.util.GroupUtil;
@@ -85,8 +86,9 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
   private static final int lokiV9                           = 30;
   private static final int lokiV10                          = 31;
   private static final int lokiV11                          = 32;
+  private static final int lokiV12                          = 33;
 
-  private static final int    DATABASE_VERSION = lokiV11; // Loki - onUpgrade(...) must be updated to use Loki version numbers if Signal makes any database changes
+  private static final int    DATABASE_VERSION = lokiV12; // Loki - onUpgrade(...) must be updated to use Loki version numbers if Signal makes any database changes
   private static final String DATABASE_NAME    = "signal.db";
 
   private final Context        context;
@@ -157,6 +159,8 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
     db.execSQL(LokiThreadDatabase.getCreatePublicChatTableCommand());
     db.execSQL(LokiUserDatabase.getCreateDisplayNameTableCommand());
     db.execSQL(LokiUserDatabase.getCreateServerDisplayNameTableCommand());
+    db.execSQL(SharedSenderKeysDatabase.getCreateClosedGroupRatchetsTableCommand());
+    db.execSQL(SharedSenderKeysDatabase.getCreateClosedGroupPrivateKeysTableCommand());
 
     executeStatements(db, SmsDatabase.CREATE_INDEXS);
     executeStatements(db, MmsDatabase.CREATE_INDEXS);
@@ -603,6 +607,11 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
         db.execSQL(LokiAPIDatabase.getCreateOpenGroupPublicKeyDBCommand());
       }
 
+      if (oldVersion < lokiV12) {
+        db.execSQL(SharedSenderKeysDatabase.getCreateClosedGroupRatchetsTableCommand());
+        db.execSQL(SharedSenderKeysDatabase.getCreateClosedGroupPrivateKeysTableCommand());
+      }
+
       db.setTransactionSuccessful();
     } finally {
       db.endTransaction();
diff --git a/src/org/thoughtcrime/securesms/loki/database/SharedSenderKeysDatabase.kt b/src/org/thoughtcrime/securesms/loki/database/SharedSenderKeysDatabase.kt
new file mode 100644
index 0000000000..749f4ba02f
--- /dev/null
+++ b/src/org/thoughtcrime/securesms/loki/database/SharedSenderKeysDatabase.kt
@@ -0,0 +1,105 @@
+package org.thoughtcrime.securesms.loki.database
+
+import android.content.ContentValues
+import android.content.Context
+import org.thoughtcrime.securesms.database.Database
+import org.thoughtcrime.securesms.database.helpers.SQLCipherOpenHelper
+import org.thoughtcrime.securesms.loki.utilities.*
+import org.thoughtcrime.securesms.util.Hex
+import org.whispersystems.signalservice.loki.protocol.closedgroups.ClosedGroupRatchet
+import org.whispersystems.signalservice.loki.protocol.closedgroups.ClosedGroupSenderKey
+import org.whispersystems.signalservice.loki.protocol.closedgroups.SharedSenderKeysDatabaseProtocol
+
+class SharedSenderKeysDatabase(context: Context, helper: SQLCipherOpenHelper) : Database(context, helper), SharedSenderKeysDatabaseProtocol {
+
+    companion object {
+        // Shared
+        private val closedGroupPublicKey = "closed_group_public_key"
+        // Ratchets
+        private val closedGroupRatchetsTable = "closed_group_ratchets"
+        private val senderPublicKey = "sender_public_key"
+        private val chainKey = "chain_key"
+        private val keyIndex = "key_index"
+        private val messageKeys = "message_keys"
+        @JvmStatic val createClosedGroupRatchetsTableCommand
+            = "CREATE TABLE $closedGroupRatchetsTable (PRIMARY KEY ($closedGroupPublicKey, $senderPublicKey), $chainKey STRING, $keyIndex INTEGER DEFAULT 0, $messageKeys STRING);"
+        // Private keys
+        private val closedGroupPrivateKeysTable = "closed_group_private_keys"
+        private val closedGroupPrivateKey = "closed_group_private_key"
+        @JvmStatic val createClosedGroupPrivateKeysTableCommand
+            = "CREATE TABLE $closedGroupPrivateKeysTable ($closedGroupPublicKey STRING PRIMARY KEY, $closedGroupPrivateKey STRING);"
+    }
+
+    // region Ratchets & Sender Keys
+    override fun getClosedGroupRatchet(groupPublicKey: String, senderPublicKey: String): ClosedGroupRatchet? {
+        val database = databaseHelper.readableDatabase
+        val query = "${Companion.closedGroupPublicKey} = ? AND ${Companion.senderPublicKey} = ?"
+        return database.get(closedGroupRatchetsTable, query, arrayOf( groupPublicKey, senderPublicKey )) { cursor ->
+            val chainKey = cursor.getString(Companion.chainKey)
+            val keyIndex = cursor.getInt(Companion.keyIndex)
+            val messageKeys = cursor.getString(Companion.messageKeys).split("-")
+            ClosedGroupRatchet(chainKey, keyIndex, messageKeys)
+        }
+    }
+
+    override fun setClosedGroupRatchet(groupPublicKey: String, senderPublicKey: String, ratchet: ClosedGroupRatchet) {
+        val database = databaseHelper.writableDatabase
+        val values = ContentValues()
+        values.put(Companion.closedGroupPublicKey, groupPublicKey)
+        values.put(Companion.senderPublicKey, senderPublicKey)
+        values.put(Companion.chainKey, ratchet.chainKey)
+        values.put(Companion.keyIndex, ratchet.keyIndex)
+        values.put(Companion.messageKeys, ratchet.messageKeys.joinToString("-"))
+        val query = "${Companion.closedGroupPublicKey} = ? AND ${Companion.senderPublicKey} = ?"
+        database.insertOrUpdate(closedGroupRatchetsTable, values, query, arrayOf( groupPublicKey, senderPublicKey ))
+    }
+
+    override fun removeAllClosedGroupRatchets(groupPublicKey: String) {
+        val database = databaseHelper.writableDatabase
+        database.delete(closedGroupRatchetsTable, null, null)
+    }
+
+    override fun getAllClosedGroupSenderKeys(groupPublicKey: String): Set<ClosedGroupSenderKey> {
+        val database = databaseHelper.readableDatabase
+        val query = "${Companion.closedGroupPublicKey} = ? AND ${Companion.senderPublicKey} = ?"
+        return database.getAll(closedGroupRatchetsTable, query, arrayOf( groupPublicKey, senderPublicKey )) { cursor ->
+            val chainKey = cursor.getString(Companion.chainKey)
+            val keyIndex = cursor.getInt(Companion.keyIndex)
+            val senderPublicKey = cursor.getString(Companion.senderPublicKey)
+            ClosedGroupSenderKey(Hex.fromStringCondensed(chainKey), keyIndex, Hex.fromStringCondensed(senderPublicKey))
+        }.toSet()
+    }
+    // endregion
+
+    // region Public & Private Keys
+    override fun getClosedGroupPrivateKey(groupPublicKey: String): String? {
+        val database = databaseHelper.readableDatabase
+        val query = "${Companion.closedGroupPublicKey} = ?"
+        return database.get(closedGroupPrivateKeysTable, query, arrayOf( groupPublicKey )) { cursor ->
+            cursor.getString(Companion.closedGroupPrivateKey)
+        }
+    }
+
+    override fun setClosedGroupPrivateKey(groupPublicKey: String, groupPrivateKey: String) {
+        val database = databaseHelper.writableDatabase
+        val values = ContentValues()
+        values.put(Companion.closedGroupPublicKey, groupPublicKey)
+        values.put(Companion.closedGroupPrivateKey, groupPrivateKey)
+        val query = "${Companion.closedGroupPublicKey} = ?"
+        database.insertOrUpdate(closedGroupPrivateKeysTable, values, query, arrayOf( groupPublicKey ))
+    }
+
+    override fun removeClosedGroupPrivateKey(groupPublicKey: String) {
+        val database = databaseHelper.writableDatabase
+        val query = "${Companion.closedGroupPublicKey} = ?"
+        database.delete(closedGroupPrivateKeysTable, query, arrayOf( groupPublicKey ))
+    }
+
+    override fun getAllClosedGroupPublicKeys(): Set<String> {
+        val database = databaseHelper.readableDatabase
+        return database.getAll(closedGroupPrivateKeysTable, null, null) { cursor ->
+            cursor.getString(Companion.closedGroupPublicKey)
+        }.toSet()
+    }
+    // endregion
+}
diff --git a/src/org/thoughtcrime/securesms/loki/utilities/DatabaseUtilities.kt b/src/org/thoughtcrime/securesms/loki/utilities/DatabaseUtilities.kt
index 8d3112939b..33d8997f02 100644
--- a/src/org/thoughtcrime/securesms/loki/utilities/DatabaseUtilities.kt
+++ b/src/org/thoughtcrime/securesms/loki/utilities/DatabaseUtilities.kt
@@ -5,7 +5,7 @@ import net.sqlcipher.Cursor
 import net.sqlcipher.database.SQLiteDatabase
 import org.whispersystems.signalservice.internal.util.Base64
 
-fun <T> SQLiteDatabase.get(table: String, query: String, arguments: Array<String>, get: (Cursor) -> T): T? {
+fun <T> SQLiteDatabase.get(table: String, query: String?, arguments: Array<String>?, get: (Cursor) -> T): T? {
     var cursor: Cursor? = null
     try {
         cursor = query(table, null, query, arguments, null, null, null)
@@ -18,7 +18,7 @@ fun <T> SQLiteDatabase.get(table: String, query: String, arguments: Array<String
     return null
 }
 
-fun <T> SQLiteDatabase.getAll(table: String, query: String, arguments: Array<String>, get: (Cursor) -> T): List<T> {
+fun <T> SQLiteDatabase.getAll(table: String, query: String?, arguments: Array<String>?, get: (Cursor) -> T): List<T> {
     val result = mutableListOf<T>()
     var cursor: Cursor? = null
     try {