METHOD AND APPARATUS FOR GENERATING A MESSAGE AUTHENTICATION CODE

摘要

A method for generating a message authentication code (MAC) includes the steps of distributing the bits of a message into a larger message in accordance with a pseudorandom number distribution format. The cyclic redundancy check (CRC) bits of the larger message are computed and used as the MAC for the message. The larger message need not be created. The remainder modulo the CRC polynomial of a polynomial x, where i is the intended bit position in the "larger message", is calculated. An exclusive-OR(XOR) operation is performed, bit by bit, on the CRC and the calculated remainder to derive the new CRC.