}
    }

    /**
     * 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