}
    }

    /**
     * Get an HMACT64 message authentication code instance.
     * @param key the key for the HMACT64 MAC
     * @return HMACT64 MAC instance
     */
    public static MessageDigest getHMACT64(final byte[] key) {
        return new HMACT64(key);
    }

    /**
     * Get an RC4 cipher instance initialized with the specified key.
     * @param key the encryption key

    void testHMACT64() {
        // Given
        byte[] key = "secret".getBytes();
        byte[] data = "Hello World".getBytes();

        // When
        MessageDigest hmac = Crypto.getHMACT64(key);
        byte[] result = hmac.digest(data);

        // Then
        assertNotNull(result);
        assertTrue(result.length > 0, "HMAC-T64 should produce non-empty result");
    }

    @Test