In addition to the key, the TMMH/16 requires three more parameters
passed to its init method, using the following three keys:
java.lang.Integer.
This value must be an even integer between 2 and 64.
gnu.crypto.prng.IRandom, which is to serve as the
source of random bytes for this instance.
TAG_LENGTH bytes. If this parameter is omitted an
all-zero byte array will be used. This value is XORed with the digest
just before it is returned.