Cipher Block Chaining (CBC) MAC

One of the algorithms (CALG_MAC) implemented by Microsoft providers is of the most common sort. That is, it is a block cipher MAC. This method encrypts the base data with a block cipher and then uses the last encrypted block as the hash value. The encryption algorithm used to build the MAC is the one that was specified when the session key was created. (For more information on block ciphers, see Block Ciphers.)