Towards a Framework on the Security Requirements for Electronic Voting Protocols

Electronic voting schemes are expected to meet the basic security requirements for electronic voting. However, very different opinions about these requirements exist in the e-voting community. This is due to the fact that the security requirements comprise different levels at which they can be met. For example, universal verifiability may, or may not, include verifying eligibility of the voters who participated in the election. This paper provides definitions of different levels of election secrecy and verifiability. We also investigate whether there exists an order for the different levels and provide adversary models. The resulting compilation is useful since it may not be necessary, or even possible, to achieve the maximum level for all the security requirements in parallel. Thus, appropriate levels of the requirements can be selected for different types of elections, e.g. parliamentary elections vs. elections in associations.