public function register($username, $email, $password)
    {
        $password_hash = password_hash($password, PASSWORD_DEFAULT);

        $user = User::create(['username' => $username, 'password' => $password_hash, 'email' => $email]);

        //Random and secure master key used for encryption / decryption of data.
        $master_key = Key::createNewRandomKey();
        $master_key_ascii = $master_key->saveToAsciiSafeString(); //Save to encrypt.

        //Password protected key.
        $keyProtectedbyPassword = KeyProtectedByPassword::createRandomPasswordProtectedKey($password);
        $user->locked_key = $keyProtectedbyPassword->saveToAsciiSafeString();

        //Unlock to use for encryption.
        $unlocked_key = $keyProtectedbyPassword->unlockKey($password);
        $user->encrypted_master_key = Crypto::encrypt($master_key_ascii, $unlocked_key);

        //keypair
        $keyPair = KeyPair::generateKeyPair(2048);
        $privateKey = $keyPair->getPrivateKey();
        $publicKey = $keyPair->getPublicKey();

        $user->public_key = $publicKey;
        $user->encrypted_private_key = Crypto::encrypt($privateKey, $master_key);
    }

    public function addPassword($password)
    {
        //get the current logged in user object/model
        $user = $this->getCurrentUser();

        $locked_key = KeyProtectedByPassword::loadFromAsciiSafeString($user->locked_key);
        $unlocked_key = $locked_key->unlockKey($user->plaintextPassword); //Important! Don't use the hashed password. Use the Password Input (Maybe from login?)

        $decrypted_master_key = Crypto::decrypt($user->encrypted_master_key, $unlocked_key);
        $master_key = Key::loadFromAsciiSafeString($decrypted_master_key);

        $user_private_key = Crypto::decrypt($user->encrypted_private_key, $master_key);

        $encrypted_password_to_add = Crypto::encrypt($password, $master_key);
    }