Research On Receipt-Free Secure Electronic Voting Protocol

Elections and voting behavior are always in our lives. As the activities increase on Internet, some elections and voting behavior would be brought on Internet. It is called"electronic voting". Electronic voting can solve the cost problem that occurs in traditional election. But electronic voting still has some problems, one of which is that it enables voting buying and coercion which are impractical in traditional election systems due to the"plausible deniability"offered by a voting booth. Therefore, for an electronic voting to be fully democratic there is a need for security mechanisms that will assure a voter neither obtains nor is able to construct a receipt proving the content of his vote, say receipt-freeness.Hirt and Sako proposed the first practicable receipt-free voting scheme based on the mix-net and the physical assumption of one-way untappable channels from the authorities to the voters. But the communication load of their mix-net to provide receipt-freeness is very high. Moreover untappable channel is hard to implement in real world and will cause inconvenience to voters although it is provided. In this paper we extend their scheme such that a tamper-resistant smart card replaces the role of mix-net and untappable channel. Compared to the receipt-free protocol of Hirt and Sako for system parameters: L(the number of all candidates), M(the number of all voters) and N(the number of talliers), the protocol described in this paper realizes an improvement of the total computation and communication complexity from O(L2MN) to O(LM). Moreover the scheme proposed in this paper is K-out-of-L and without any physical channel assumption, so it is more general and applied.