2018-05-07: The Verificatum Project 10-year Anniversary

Abstract

A mix-net is a way for a group of servers to decrypt a set of ciphertexts in such a way that it is infeasible to find any correspondencebetween the individual inputs and output plaintexts. This idea originates in theseminal work of Chaum 1982 and the main application is electronicelections and related notions.

The Verificatum Mix-Net (VMN) was the first fully distributed implementation of a provably secure mix-net. The first version was completed 2008. Today it is licensed under AGPL.

Some key cryptographic protocols were developed at KTH, but the main contribution is what can be learned from the project as a whole and its application in real electronic voting systems. VMN is completely faithful to cryptographic theory, yet adopts best practices from real-world software engineering.

This was one of the first research projects with this focus (2007) and paved the way to what today is often referred to as real-world crypto. It is the only implementation of a mix-net from the research community that has been considered fit for use by national election authorities.

We first give an overview of a class of electronic voting systems and explain the role of mix-nets in the greater whole. Then we describe the state of the project today. We also give a historical account with afocus on mistakes and what we can learn from them.

Then we take a pause. The historical account leads us in anatural way into difficult tradeoffs and the uncharted territory wheretheory and practice are supposed to meet. This may be a Q&A session or a more mutual discussion depending on what the audience prefers.