Paper 2018/404
Enforcing ideal-world leakage bounds in real-world secret sharing MPC frameworks
José Bacelar Almeida, Manuel Barbosa, Gilles Barthe, Hugo Pacheco, Vitor Pereira, and Bernardo Portela
Abstract
We give a language-based security treatment of domain-specific languages and compilers for secure multi-party computation, a cryptographic paradigm that enables collaborative computation over encrypted data. Computations are specified in a core imperative language, as if they were intended to be executed by a trusted-third party, and formally verified against an information-flow policy modelling (an upper bound to) their leakage. This allows non-experts to assess the impact of performance-driven authorized disclosure of intermediate values. Specifications are then compiled into multi-party protocols. We formalize protocol security using (distributed) probabilistic information-flow and prove that compilation is security-preserving: protocols do not leak more than allowed by the source policy. The proof exploits a natural but previously missing correspondence between simulation-based cryptographic proofs and (composable) probabilistic non-interference. Finally, we extend our framework to justify leakage cancelling, a domain-specific optimization that allows to, first, write an efficiently computable specification that fails to meet the allowed leakage upper-bound, and then apply a probabilistic pre-processing that brings the overall leakage to within the acceptable range.
Metadata
- Available format(s)
-
PDF
- Publication info
- Published elsewhere. Major revision. 31st IEEE Computer Security Foundations Symposium
- Keywords
- Domain-specific languagesPrivacySecuritySemanticsType systemsVerificationMulti-party computationSecure compilation
- Contact author(s)
- vitor m pereira @ inesctec pt
- History
- 2018-05-10: received
- Short URL
- https://ia.cr/2018/404
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2018/404,
author = {José Bacelar Almeida and Manuel Barbosa and Gilles Barthe and Hugo Pacheco and Vitor Pereira and Bernardo Portela},
title = {Enforcing ideal-world leakage bounds in real-world secret sharing {MPC} frameworks},
howpublished = {Cryptology {ePrint} Archive, Paper 2018/404},
year = {2018},
url = {https://eprint.iacr.org/2018/404}
}