diff --git a/ConversationsClassic/AppData/Client/Client+MartinOMEMO.swift b/ConversationsClassic/AppData/Client/Client+MartinOMEMO.swift
index b5749f5..2cc0236 100644
--- a/ConversationsClassic/AppData/Client/Client+MartinOMEMO.swift
+++ b/ConversationsClassic/AppData/Client/Client+MartinOMEMO.swift
@@ -145,31 +145,124 @@ extension ClientMartinOMEMO: SignalSessionStoreProtocol {
 // MARK: - PreKey
 extension ClientMartinOMEMO: SignalPreKeyStoreProtocol {
     func currentPreKeyId() -> UInt32 {
-        0
+        do {
+            let data = try Database.shared.dbQueue.read { db in
+                try Row.fetchOne(
+                    db,
+                    sql: "SELECT max(id) FROM omemo_pre_keys WHERE account = :account",
+                    arguments: ["account": credentials.bareJid]
+                )
+            }
+            return data?["id"] ?? 0
+        } catch {
+            logIt(.error, "Error fetching chats: \(error.localizedDescription)")
+            return 0
+        }
     }
 
     func loadPreKey(withId: UInt32) -> Data? {
-        print(withId)
-        return nil
+        do {
+            let data = try Database.shared.dbQueue.read { db in
+                try Row.fetchOne(
+                    db,
+                    sql: "SELECT key FROM omemo_pre_keys WHERE account = :account AND id = :id",
+                    arguments: ["account": credentials.bareJid, "id": withId]
+                )
+            }
+            return data?["key"]
+        } catch {
+            logIt(.error, "Error fetching chats: \(error.localizedDescription)")
+            return nil
+        }
     }
 
     func storePreKey(_ data: Data, withId: UInt32) -> Bool {
-        print(data, withId)
-        return false
+        do {
+            try Database.shared.dbQueue.write { db in
+                try db.execute(
+                    sql: "INSERT INTO omemo_pre_keys (account, id, key) VALUES (:account, :id, :key)",
+                    arguments: ["account": credentials.bareJid, "id": withId, "key": data]
+                )
+            }
+            return true
+        } catch {
+            logIt(.error, "Error fetching chats: \(error.localizedDescription)")
+            return false
+        }
     }
 
     func containsPreKey(withId: UInt32) -> Bool {
-        print(withId)
-        return false
+        do {
+            let rec = try Database.shared.dbQueue.read { db in
+                try Row.fetchOne(
+                    db,
+                    sql: "SELECT key FROM omemo_pre_keys WHERE account = :account AND id = :id",
+                    arguments: ["account": credentials.bareJid, "id": withId]
+                )
+            }
+            return rec != nil
+        } catch {
+            logIt(.error, "Error fetching chats: \(error.localizedDescription)")
+            return false
+        }
     }
 
     func deletePreKey(withId: UInt32) -> Bool {
-        print(withId)
-        return false
+        do {
+            try Database.shared.dbQueue.write { db in
+                try db.execute(
+                    sql: "DELETE FROM omemo_pre_keys WHERE account = :account AND id = :id",
+                    arguments: ["account": credentials.bareJid, "id": withId]
+                )
+            }
+            return true
+        } catch {
+            logIt(.error, "Error fetching chats: \(error.localizedDescription)")
+            return false
+        }
     }
 
+    // TODO: Check logic of this function carefully!!!
     func flushDeletedPreKeys() -> Bool {
-        false
+        do {
+            try Database.shared.dbQueue.write { db in
+                try db.execute(
+                    sql: """
+                    DELETE FROM omemo_pre_keys 
+                    WHERE account = :account 
+                    AND id IN 
+                        (SELECT id 
+                         FROM omemo_pre_keys 
+                         WHERE account = :account 
+                         AND id NOT IN (
+                            SELECT id 
+                            FROM omemo_pre_keys 
+                            WHERE account = :account 
+                            ORDER BY id DESC 
+                            LIMIT 100)
+                         )
+                    """,
+                    arguments: ["account": credentials.bareJid]
+                )
+            }
+            return true
+        } catch {
+            logIt(.error, "Error fetching chats: \(error.localizedDescription)")
+            return false
+        }
+    }
+
+    func preKeysWipe() {
+        do {
+            try Database.shared.dbQueue.write { db in
+                try db.execute(
+                    sql: "DELETE FROM omemo_pre_keys WHERE account = :account",
+                    arguments: ["account": credentials.bareJid]
+                )
+            }
+        } catch {
+            logIt(.error, "Error fetching chats: \(error.localizedDescription)")
+        }
     }
 }