Secure message authentication for binary additive stream cipher systems.

摘要

The method of verifying the authenticity of a message involves secretly exchanging an encryption key and an irreducible polynomial. For each message to be transmitted by the sender, a leading non-zero string and n tail bits are appended to the message to generate an augmented message that corresponds to a polynomial having coefficients corresp. to bits of the message. A polynomial residue resulting from the division of the polynomial corresp. to the augmented message is computed. The residue is encrypted using the encryption key. The message and the encrypted residue are transmitted. The receiver decrypts the transmitted encrypted residue at the time of reception using the encryption key. The decrypted residue is concatenated with a received message and a non-zero leading string is appended to generate an augmented received message. A residue of a division between a polynomial represented by the augmented message and the polynomial is computed. The received message is accepted as authentic only if the residue is a predetermined value.