On the Automated Correction of Protocols with Improper Message Encoding

Abstract

Abstract. Security protocols are crucial to achieve trusted computing. However, designing security protocols is not easy and so security protocols are typically faulty and have to be repaired. Continuing previous work we present first steps to automate this repairing process, especially for protocols that are susceptible to type-flaw attacks. To this end, we extend the notion of strand spaces by introducing an implementation layer for messages and extending the capabilities of a penetrator to swap messages that share the same implementation. Based on this framework we are able to track type flaw attacks to incompatibilities between the way messages are implemented and the design of concrete security protocols. Heuristics are given to either change the implementation or the protocol to avoid these situations.