Probabilistic Opacity for a Passive Adversary and its Application to Chaum's Voting Scheme

Yassine Lakhnech; Laurent Mazare

Paper 2005/098

Probabilistic Opacity for a Passive Adversary and its Application to Chaum's Voting Scheme

Yassine Lakhnech and Laurent Mazare

Abstract

A predicate is opaque for a given system, if an adversary will never be able to establish truth or falsehood of the predicate for any observed computation. This notion has been essentially introduced and studied in the context of transition systems whether describing the semantics of programs, security protocols or other systems. In this paper, we are interested in studying opacity in the probabilistic computational world. Indeed, in other settings, as in the Dolev-Yao model for instance, even if an adversary is sure of the truth of the predicate, it remains opaque as the adversary cannot conclude for sure. In this paper, we introduce a computational version of opacity in the case of passive adversaries called cryptographic opacity. Our main result is a composition theorem: if a system is secure in an abstract formalism and the cryptographic primitives used to implement it are secure, then this system is secure in a computational formalism. Security of the abstract system is the usual opacity and security of the cryptographic primitives is IND-CPA security. To illustrate our result, we give two applications: a short and elegant proof of the classical Abadi-Rogaway result and the first computational proof of Chaum's visual electronic voting scheme.

Metadata

Available format(s): PDF PS
Publication info: Published elsewhere. Unknown where it was published
Keywords: Opacity Non-Interference Chaum's Voting Scheme Computational Model Probabilistic Encryption
Contact author(s): laurent mazare @ imag fr
History: 2005-04-05: received
Short URL: https://ia.cr/2005/098
License: CC BY

BibTeX

@misc{cryptoeprint:2005/098,
      author = {Yassine Lakhnech and Laurent Mazare},
      title = {Probabilistic Opacity for a Passive Adversary and its Application to Chaum's Voting Scheme},
      howpublished = {Cryptology {ePrint} Archive, Paper 2005/098},
      year = {2005},
      url = {https://eprint.iacr.org/2005/098}
}