@inproceedings{barthe2010a, author = {Barthe, Gilles and Hedin, Daniel and Zanella-Béguelin, Santiago and Grégoire, Benjamin and Heraud, Sylvain}, title = {A Machine-Checked Formalization of Sigma-Protocols}, booktitle = {23rd IEEE Computer Security Foundations Symposium, CSF 2010}, year = {2010}, month = {January}, abstract = {Zero-knowledge proofs have a vast applicability in the domain of cryptography, stemming from the fact that they can be used to force potentially malicious parties to abide by the rules of a protocol, without forcing them to reveal their secrets. Sigma-protocols are a class of zero-knowledge proofs that can be implemented efficiently and that suffice for a great variety of practical applications. This paper presents a first machine-checked formalization of a comprehensive theory of Sigma-protocols. The development includes basic definitions, relations between different security properties that appear in the literature, and general composability theorems. We show its usefulness by formalizing—and proving the security—of concrete instances of several well-known protocols. The formalization builds on CertiCrypt, a framework that provides support to reason about cryptographic systems in the Coq proof assistant, and that has been previously used to formalize security proofs of encryption and signature schemes.}, publisher = {IEEE Computer Society}, url = {http://approjects.co.za/?big=en-us/research/publication/a-machine-checked-formalization-of-sigma-protocols/}, pages = {246-260}, edition = {23rd IEEE Computer Security Foundations Symposium, CSF 2010}, }