Symbolic Methods in Computational Cryptography Proofs

Gilles Barthe, Benjamin Gregoire, Charlie Jacomme, Steve Kremer, Pierre-Yves Strub
2019 2019 IEEE 32nd Computer Security Foundations Symposium (CSF)  
Code-based game-playing is a popular methodology for proving security of cryptographic constructions and sidechannel countermeasures. This methodology relies on treating cryptographic proofs as an instance of relational program verification (between probabilistic programs), and decomposing the latter into a series of elementary relational program verification steps. In this paper, we develop principled methods for proving such elementary steps for probabilistic programs that operate over finite
more » ... fields and related algebraic structures. We focus on three essential properties: program equivalence, information flow, and uniformity. We give characterizations of these properties based on deducibility and other notions from symbolic cryptography. We use (sometimes improve) tools from symbolic cryptography to obtain decision procedures or sound proof methods for program equivalence, information flow, and uniformity. Finally, we evaluate our approach using examples drawn from provable security and from sidechannel analysis-for the latter, we focus on the masking countermeasure against differential power analysis. A partial implementation of our approach is integrated in EASYCRYPT, a proof assistant for provable security, and in MASKVERIF, a fully automated prover for masked implementations.
doi:10.1109/csf.2019.00017 dblp:conf/csfw/BartheGJKS19 fatcat:bdp72veonjdvbksf32gbqwqmxu