Council of Europe Recommendation CM/Rec(2017)5 and e-Voting Protocol Design

The Corona pandemic has created a push towards digitization in a number of fields, not least in the public sector including democratic processes. This of course includes an increased interest in e-voting via the Internet. The Council of Europe has a long-standing history of work in the field including two Recommendations – (2004)11 and (2017)5 – which have become the de facto yardstick against which every e-voting system is measured. Rec(2017)5 builds on a decade of experience with e-voting and particularly strengthens two concepts important in any electronic voting system: Voting secrecy and auditability/verifiability. This has distinct implications for the design of e-voting protocols. The aim of this paper is to analyse the impact on what arguably are the most popular voting protocol families, envelope and token protocols. How does the modified Recommendation impact on the viability of protocols and protocol design? The paper first presents the Council of Europe Recommendation and the technical issues it addresses. Then a model is introduced to assess a voting protocol against the Recommendation; a typical envelope and a token protocol are assessed in view of the model and finally the two assessments are compared including policy recommendations for a path to e-voting implementation.