Security protocol specification and verification with AnBx

Abstract

Designing distributed protocols is complex and requires actions at very different levels: from the design of an interaction flow supporting the desired application-specific guarantees, to the selection of the most appropriate network-level protection mechanisms. To tame this complexity, we propose AnBx , a formal protocol specification language based on the popular Alice & Bob notation. AnBx offers channels as the main abstraction for communication, providing different authenticity and/or confidentiality guarantees for message transmission. AnBx extends existing proposals in the literature with a novel notion of forwarding channels, enforcing specific security guarantees from the message originator to the final recipient along a number of intermediate forwarding agents. We give a formal semantics of AnBx in terms of a state transition system expressed in the AVISPA Intermediate Format. We devise an ideal channel model and a possible cryptographic implementation, and we show that, under mild restrictions, the two representations coincide, thus making AnBx amenable to automated verification with different tools. We demonstrate the benefits of the declarative specification style distinctive of AnBx by revisiting the design of two existing e-payment protocols, iKP and SET.

AnBx: Automatic Generation and Verification of Security Protocols Implementations

“…On the formal side, the soundness of the translation from AnBx to AnB , for a specific channel implementation, has been proven in [16]. At the moment, we do not verify the concrete Java code which may be part of the future work.…”

Integrating Formal Methods for Security in Software Security Education

“…Moreover, in order to widen the adoption of these tools among practitioners, simple languages based on the Alice and Bob notation (Mödersheim, 2009) have been adopted for the specification of security protocols (Basin et al, 2015;Bugliesi, Calzavara et al, 2016;Bugliesi and Modesti 2010). This simplifies the coding, especially for beginning or intermediate computer science students, and the code itself is more succinct than its equivalent in other formal languages like the process calculi (e.g.…”

A Methodology for Protocol Verification Applied to EMV® 1

“…The AnB language [36] is a simple, abstract, and declarative language, where AnBx [11,12] is a syntactic extension including various useful patterns of use and a stronger type system for user-defined (abstract) function symbols. Its key feature is the declaration of Agents representing protocol actors, Actions representing message exchanges between agents, and Goals representing desired properties of interest for the messages exchanged to have.…”