Authentication codes under impersonation attack

Abstract

Performance of authentication codes under impersonation attack is considered. We assume two classes of strategies for the enemy and give expressions for the probability of success in each case and study the relationship of the two classes. We prove a new lower bound on the probability of deception which points out the importance of the average. distance between the encoding rules of the code in the protection provided by it. Codes with perfect protection for each class are characterized and some constructions based on error correcting codes are proposed.