Anonymity and everlasting privacy in electronic voting

Everlasting privacy protects cryptographic voting systems against the weakening of intractability assumptions on which they may be based. We find that everlasting privacy can be obtained from protocols that do not require trust in the election talliers for privacy, as long as they are accompanied by anonymous casting. To this end, we define a novel model, , to analyze such schemes. We draw inspiration from the de facto standard framework for ballot privacy, BPRIV. We then extend to account for everlasting privacy. Our work differs from related attempts, which only consider everlasting privacy in the context of publicly available data. Our model is fine-grained, since it also considers the level of data leakage from the various components of an election system. We evaluate our definitions by applying our models to two protocols, each representing an important paradigm for building e-voting schemes.