A Framework for Analyzing Probabilistic Protocols and Its Application to the Partial Secrets Exchange

Abstract

Abstract. We propose a probabilistic variant of the pi-calculus as a framework to specify randomized security protocols and their intended properties. In order to express an verify the correctness of the protocols, we develop a probabilistic version of the testing semantics. We then illustrate these concepts on an extended example: the Partial Secret Exchange, a protocol which uses a randomized primitive, the Oblivious Transfer, to achieve fairness of information exchange between two parties.

A quantitative doxastic logic for probabilistic processes and applications to information-hiding

“…Here we are able to make such distinction, and we express strong anonymity in terms of belief (see Section 4). A similar consideration holds for the properties of the Oblivious Transfer analysed in (Chatzikokolakis et al, 2007a), which are represented here by using both belief and probabilistic truth (see Section 5).…”

“…The formulas of DµCEC are interpreted in terms of the processes of a small protocol specification formalism, namely CCS with probabilistic internal choice (CCS p ), which is a variant of the language proposed in (Chatzikokolakis et al, 2007a;Chatzikokolakis et al, 2007b). We show some application examples of our logic to the archetypical dining cryptographers (Chaum, 1988), and to oblivious transfer (Rabin, 1981) for single bits and entire strings.…”

“…In (Chatzikokolakis et al, 2009) we have refined that framework by using an information-theoretic approach, and in (Beauxis et al, 2008) we have presented an overview of the various frameworks in literature for formalizing the notion of (absence of) leakage in information-hiding protocol. In (Chatzikokolakis et al, 2007b;Chatzikokolakis et al, 2007a) we have developed a probabilistic version of CCS and of the π-calculus respectively. In (Chatzikokolakis et al, 2007a) we have used the latter to model the oblivious transfer, and we have proved its correctness by extending standard process-theoretic techniques.…”

“…In (Chatzikokolakis et al, 2007b;Chatzikokolakis et al, 2007a) we have developed a probabilistic version of CCS and of the π-calculus respectively. In (Chatzikokolakis et al, 2007a) we have used the latter to model the oblivious transfer, and we have proved its correctness by extending standard process-theoretic techniques.…”

“…In this section, we give a brief introduction to probability spaces, probabilistic automata (Segala, 1995;Segala et al, 1995), and probabilistic CCS (Chatzikokolakis et al, 2007b;Chatzikokolakis et al, 2007a).…”