Automatic Verification of Security Properties in Remote Internet Voting Protocol with Applied Pi Calculus

Abstract

Soundness and coercion resistance are the important and intricate security requirements for remote voting protocols. Several formal models of soundness and coercion-resistance have been proposed in the literatures, but these formal models are not supported by automatic tools. Recently Backes et al. propose a new formal automated model of security properties including soundness and coercionresistance in applied pi calculus. Meng protocol is one of the leading remote internet voting protocols that claims to satisfy formal definitions of key properties, such as soundness, individual verifiability, as well as receipt-freeness and coercion resistance with weak physical constrains. But in his paper the analysis of its claimed security properties is finished in manual way which depends on experts’ knowledge and skill and is prone to make mistakes. Owning to the contribution of Backes et al., Meng protocol can be analyzed with automatic tool.In this study firstly the review of the formal method of security protocols are introduced then applied pi calculus and the automatic tool ProVerif are examined. Thirdly Meng protocol is modeled in applied pi calculus. Finally security properties, including soundness and coercion resistance, are verified with ProVerif, a resolution-based theorem prover for security protocols. The result we obtain is that Meng protocol has coercion resistance. But it has not soundness because ProVerif found an attack on soundness. Finally the improvement of Meng protocol is proposed, and also modeled in applied pi calculus and automatically analyzed in ProVerif. The result we get is that the improvement of Meng protocol has soundness. To our best knowledge, the first automated analysis of Meng protocol for an unbounded number of honest and corrupted voters is finished