The CL-Atse Protocol Analyser

This paper presents an overview of the CL-Atse tool, an efficient and versatile automatic analyser for the security of cryptographic protocols. CL-Atse takes as input a protocol specified as a set of rewriting rules (IF format, produced by the AVISPA compiler), and uses rewriting and constraint solving techniques to model all reachable states of the participants and decide if an attack exists w.r.t. the Dolev-Yao intruder. Any state-based security property can be modelled (like secrecy, authentication, fairness, etc...), and the algebraic properties of operators like xor or exponentiation are taken into account with much less limitations than other tools, thanks to a complete modular unification algorithm. Also, useful constraints like typing, inequalities, or shared sets of knowledge (with set operations like removes, negative tests, etc...) can also be analysed.