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We present an efficient and provably-secure e-voting protocol, which is a variant of the JCJ e-votingprotocol (Juels et al., 2010). It decreases the total number of JCJ's operations from O(n2) to O(n), where n is the number of votes or voters (whichever is the maximum). Note that since the operations under consideration are time-consuming (e.g., public-key encryption), the improvement is quite substantial. As a rough comparison, consider a nation-wide election with around ten million voters/votes. Assuming each operation takes one microsecond, and no parallelization is used, one can see a huge difference: our protocol tallies the votes in 10 seconds, while the JCJ protocol requires over 3... 

Traffic analysis is a type of attack on secure communications systems, in which the adversary extracts useful patterns and information from the observed traffic. This paper improves and extends an efficient traffic analysis attack, called "statistical disclosure attack. " Moreover, we propose a solution to defend against the improved (and, a fortiori, the original) statistical disclosure attack. Our solution delays the attacker considerably, meaning that he should gather significantly more observations to be able to deduce meaningful information from the traffic  

Chevallier-Mames et al, proved that in a specific condition (such as the lack of untappable channels and trusted-third parties), the universal verifiability and privacy-preserving properties of e-voting protocols are incompatible (WOTE'06 and TTE'10). In this paper, we first show a flaw in their proof. Then, we prove that even with more assumptions, such as the existence of TTPs and untappable channels between the authorities, an e-voting protocol is unable to preserve privacy, regardless of verifiability. Finally, we demonstrate that preserving privacy in e-voting protocols requires the provision of at least one of the following assumptions: limited computational power of adversary,...