}

        return null;
    }

    /**
     * Remove and securely wipe a session key
     *
     * @param sessionId unique session identifier
     */
    public void removeSessionKey(String sessionId) {
        checkNotClosed();

        // Remove from memory maps
        SecretKey secretKey = sessionKeys.remove(sessionId);
        byte[] rawKey = rawKeys.remove(sessionId);

            String encKeyId = sessionId + "-enc";
            String decKeyId = sessionId + "-dec";

            // Remove old keys
            keyManager.removeSessionKey(encKeyId);
            keyManager.removeSessionKey(decKeyId);

            // Store new keys
            keyManager.storeSessionKey(encKeyId, newEncryptionKey, "AES");
            keyManager.storeSessionKey(decKeyId, newDecryptionKey, "AES");

        String sessionId = "test-session-3";
        keyManager.storeSessionKey(sessionId, testKey, "AES");

        assertTrue(keyManager.hasSessionKey(sessionId), "Key should exist");

        keyManager.removeSessionKey(sessionId);

        assertFalse(keyManager.hasSessionKey(sessionId), "Key should be removed");
        assertNull(keyManager.getSessionKey(sessionId), "Should not retrieve removed key");
    }

    @Test

            this.password = null;
        }
        // Also remove from secure key manager if we have a session
        if (this.sessionId != null) {
            keyManager.removeSessionKey(this.sessionId);
            this.sessionId = null;
        }
    }

    /**
     * Check if the authentication has expired based on TTL
     *
     * @return true if expired, false otherwise