Paper Info
Title
Mechanized Proofs of Adversarial Complexity and Application to Universal Composability
Abstract
ABSTRACTIn this paper we enhance the EasyCrypt proof assistant to reason about computational complexity of adversaries. The key technical tool is a Hoare logic for reasoning about computational complexity (execution time and oracle calls) of adversarial computations. Our Hoare logic is built on top of the module system used by EasyCrypt for modeling adversaries. We prove that our logic is sound w.r.t. the semantics of EasyCrypt programs --- we also provide full semantics for the EasyCrypt module system, which was previously lacking. We showcase (for the first time in EasyCrypt and in other computer-aided cryptographic tools) how our approach can express precise relationships between the probability of adversarial success and their execution time. In particular, we can quantify existentially over adversaries in a complexity class, and express general composition statements in simulation-based frameworks. Moreover, such statements can be composed to derive standard concrete security bounds for cryptographic constructions whose security is proved in a modular way. As a main benefit of our approach, we revisit security proofs of some well-known cryptographic constructions and we present a new formalization of Universal Composability (UC).
Year
DOI
Venue
2021
10.1145/3460120.3484548
Computer and Communications Security
Keywords
DocType
Volume
Verification of Cryptographic Primitives, Formal Methods, Interactive Proof System, Complexity Analysis
Conference
2021
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Manuel Barbosa133724.91
Gilles Barthe22337152.36
Benjamin Grégoire381748.93
Adrien Koutsos4133.98
Pierre-Yves Strub554029.87