Efficient Representation of the Attacker's Knowledge in Cryptographic Protocols Analysis

This paper addresses the problem of representing the intruder's knowledge in the formal verification of cryptographic protocols, whose main challenges are to represent the intruder's knowledge efficiently and without artificial limitations on the structure and size of messages. The new knowledge representation strategy proposed in this paper achieves both goals and leads to practical implementation because it is incrementally computable and is easily amenable to work with various term representation languages. In addition, it handles associative and commutative term composition operators, thus going beyond the free term algebra framework. An extensive computational complexity analysis of the proposed representation strategy is included in the paper.