From One Session to Many: Dynamic Tags for Security Protocols

Abstract

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 paper, 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. The proof of our result is closely tied to a particular constraint solving procedure by Comon-Lundh et al.

Challenges in the Automated Verification of Security Protocols

“…For instance [43] assumes that any two distinct terms headed with encryption, that occur in the protocol, are not unifiable. A similar result is shown in [6] for another class of protocols. However, in both cases, only secrecy is considered and the simple intruder deduction system is the one of example 1 (for symmetric and asymmetric encryption).…”

The Open-Source Fixed-Point Model Checker for Symbolic Analysis of Security Protocols

“…First, we have message terms as we have them in AnB, with the same convention that constants start with a lower-case letter and variables with an upper-case letter. 4 On top of that, we have facts, which are built using distinguished function symbols and have message terms as arguments. For instance, iknows(m) denotes the fact that the intruder knows the message m, and state R (m 1 , .…”

“…[1,2,4,5,6,13,15,18,20,21,24,25,27,29,37,43,49,51,53,59,61,62,63]. The Open Source Fixed-point Model Checker OFMC, the successor of the On-theFly Model-Checker [12,54,58], is a freely available 1 tool that integrates the most successful techniques of this field.…”

Lightweight RFID authentication with forward and backward security

“…Some researchers have adopted a systematic approach designed to capture specific security requirements by using privacy models (e.g., [Paise and Vaudenay 2008;Juels and Weis 2009;Michahelles et al 2007;Avoine et al 2007]; computational models (e.g., [Vaudenay 2007]); or symbolic models (e.g., [Arapinis et al 2008]). In this article we propose to use a formal specifications-based framework that captures these models and addresses composability issues.…”