Implementing broadcast channels with memory for electronic voting systems

To provide universal verifiability, cryptographic voting protocols often require a broadcast channel to spread the election data to the public. The basic requirements on such a broadcast channel are similar for most protocols, for example that the channel maintains a memory of all broadcast messages and that nothing can be deleted from the channel’s memory. In this paper, we provide a formal definition for such broadcast channels with memory and describe their properties. We also analyze the significance of a broadcast channel with memory in cryptographic voting protocols and propose that such a channel is provided in form of a service that we call bulletin board. Based on this service, we analyze some real-world problems that cryptographic voting protocols might have and provide possible solutions. For this we define a generic interface for the main board functionalities, which offers a flexible way of extending the basic properties of a bulletin board to comply with all sorts of additional requirements

Coercion-Resistant Hybrid Voting Systems

Abstract: This paper proposes hybrid voting systems as a solution for the vote buying and voter coercion problem of electronic voting systems. The key idea is to allow voters to revoke and overrule their electronic votes at the polling station. We analyze the potential and pitfalls of such revocation procedures and give concrete recommendations on how to build a hybrid system offering coercion-resistance based on this feature. Our solution may be of interest to governments, which aim at integrating paper-based and electronic voting systems rather than replacing the former by the latter.

Pseudo-Code Algorithms for Verifiable Re-Encryption Mix-Nets

Implementing the shuffle proof of a verifiable mix-net is one of the most challenging tasks in the implementation of an electronic voting system. For non-specialists, even if they are experienced software developers, this task is nearly impossible to fulfill without spending an enormous amount of resources into studying the necessary cryptographic theory. In this paper, we present one of the existing shuffle proofs in a condensed form and explain all the necessary technical details in corresponding pseudo-code algorithms. The goal of presenting the shuffle proof in this form is to make it accessible to a broader audience and to facilitate its implementation by non-specialists