Formal Analysis of Non-Malleability for Commitment Schemes in EasyCrypt
Abstract
In this work, we perform a formal analysis of definitions of non-malleability for commitment
schemes in the EasyCrypt theorem prover. There are two distinct formulations
of non-malleability found in the literature: the comparison-based definition and the
simulation- based definition. In this paper, we do a formal analysis of both. We start by
formally proving that the comparison-based definition which was originally introduced
by Laur et al. is unsatisfiable. Also, we propose a novel formulation of simulation-based
non-malleability. Moreover, we validate our definition by proving that it implies hiding
and binding of commitment schemes.
Description
Keywords
Cryptography, commitments, non-malleability, formal methods, EasyCrypt