The UMAC-32 algorithm requires, in addition to the key, a nonce byte
array. The byte array must be 1–16 bytes of random data, which is
passed to the init method of IMac in the attributes map.
UMac32 defined an additional key for this map:
— Variable: java.lang.String NONCE_MATERIAL
The key for the nonce material for the attributes map. The value
mapped must be a byte array of size 1–16 bytes.