Abstracting cryptographic protocols with tree automata

Cryptographic protocols have so far been analyzed for the most part by means of testing (which does not yield proofs of secrecy) and theorem proving (costly). We propose a new approach, based on abstract interpretation and using regular tree languages. The abstraction we use seems fine-grained enough to be able to certify some protocols. Both the concrete and abstract semantics of the protocol description language and implementation issues are discussed in the paper.