基于安全多方求和的多候选人电子选举方案

多候选人电子选举方案在许多实际环境下具有重要的应用价值，但现有绝大多数方案由于技术限制只能进行“两选一”投票.设计了一种新型的选票结构，在一个多精度数中隐藏“m选k”形式的选票，对m个候选人至多可以投k个赞成票；将多精度计算及安全多方求和协议应用于投票和计票，选举过程中不需要可信任第3方，任何投票人都可以计票.与一般方案相比，该方案具有更强的安全性，包括选票的完全保密性和无收据性、计票的公平性和无争议性、系统的健壮性等；无需使用传统的加密技术.对n个投票人，计算的位复杂性为O(nm(log_2 n))，其效率优于现有方案且容易实现.

A Multi-Candidate Electronic Voting Scheme Based on Secure Sum Protocol

Multi-candidate electronic voting is very useful in numerous practical situations. Most of the previous schemes discuss Boolean vote in which voters can only cast “yes/no” vote. A novel multi-candidates election scheme is presented which is appropriate for k-out-of-m election. The main idea is to express a ballot by a multi-precision number that allows voting for up to k out of the m candidates in one ballot. The purpose of the vote is to elect more than one winner among m candidates. The self-tallying protocol in the solution is based on the multi-precision arithmetic and the secure sum protocol without any trusted third party. In comparison with general methods, the results of this paper don't rely on any traditional cryptography or computation intractability assumption that is information-theoretically secure. This scheme achieves security including perfect ballot secrecy, receipt-free and dispute-freeness tally that extend the previous general security. Each participant takes only O(nm(log_2 n)) bit operations, which is more efficient than previous schemes. The scheme is very practical and can be efficiently implemented.