Encrypted Message Check Bits as Intelligent ID Card Signature
Original Publication Date: 1980-Jun-01
Included in the Prior Art Database: 2005-Feb-13
Message check bits appended to each message for error detection can be encrypted with an encryption key which is only available to the parties to a secured communication. When the recipient receives the message, regenerates the check bits from the received message, and encrypts the regenerated check bits with the encryption key, the encrypted regenerated check bits should be identical to the encrypted original check bits appended to the message by the sender. If not identical, either there has been an error in the message or the sender is an intruder into the secured communication who does not possess the encryption key. This method is particularly useful when communicating between an intelligent ID card and a host computer of the bank or other institution which owns the ID card.