Cryptographic Choreographies
Abstract
We present CryptoChoreo, a choreography language for the specification of cryptographic protocols. Choreographies can be regarded as an extension of Alice-and-Bob notation, providing an intuitive high-level view of the protocol as a whole (rather than specifying each protocol role in isolation). The extensions over standard Alice-and-Bob notation that we consider are non-deterministic choice, conditional branching, and mutable long-term memory. We define the semantics of CryptoChoreo by translation to a process calculus. This semantics entails an understanding of the protocol: it determines how agents parse and check incoming messages and how they construct outgoing messages, in the presence of an arbitrary algebraic theory and non-deterministic choices made by other agents. While this semantics entails algebraic problems that are in general undecidable, we give an implementation for a representative theory. We connect this translation to ProVerif and show on a number of case studies that the approach is practically feasible.
Cite
@article{arxiv.2602.12967,
title = {Cryptographic Choreographies},
author = {Sebastian Mödersheim and Simon Lund and Alessandro Bruni and Marco Carbone and Rosario Giustolisi},
journal= {arXiv preprint arXiv:2602.12967},
year = {2026}
}