From one Session to many: Dynamic Tags for Security Protocols

Myrto Arapinis :: Thursday 16th October 2008

Abstract. The design and verification of cryptographic protocols is a notoriously difficult task, even in abstract Dolev-Yao models. This is mainly due to several sources of unboundedness (size of messages, number of sessions, ... ). In this work, we characterize a class of protocols for which secrecy for an unbounded number of sessions is decidable. More precisely, we present a simple transformation which maps a protocol that is secure for a single protocol session (a decidable problem) to a protocol that is secure for an unbounded number of sessions. Our result provides an effective strategy to design secure protocols: (i) design a protocol intended to be secure for one protocol session (this can be verified with existing automated tools); (ii) apply our transformation and obtain a protocol which is secure for an unbounded number of sessions.

Materials: slides (.pdf)