Verificatum

Verificatum is part of an ongoing research project at the Theory group of the School of Computer Science and Communication of the Royal Institute of Technology. The project is partly funded by the Swedish Foundation for Strategic Research and the goal of the project is to implement an easy-to-use, full-featured, free, open source, complete, fast, and provably secure mix-net.

The main author of the software is Douglas Wikström, but we are cooperating with other research groups and developers. If you are interested in contributing to the project or simply plan to use it, then email us!

Read the detailed description for more information about the library and the news for recent developments.

Download and Install Verificatum

Download the most recent distributions and/or read the detailed installation instructions.

Download is disabled and the repository is private while we are reworking things.

Documentation

• User Manual for the Verificatum Mix-Net. This targets operators of the mix-net and assumes that Verificatum has already been installed.
• How to Implement a Stand-alone Verifier for the Verificatum Mix-Net. The Verificatum Mix-Net can optionally use the Fiat-Shamir heuristic to produce non-interactive zero-knowledge proofs of correctness. This document targets implementers of stand-alone verifiers of such proofs.
• Description and analysis of abstract protocol. This document is still in preparation and targets cryptographers and other interested with some mathematical background. It will contain a complete self-contained description of the abstract protocol and an exact proof of security. A short bullet-list of the protocols we use can be found here

Stand-alone Verifiers

• Built-in verifier. Verificatum has its own verifier vmnv. This is based on the same libraries as the mix-net itself, it is fast, and it can perform both the core verification and the overall verification for any mix-net interface and any set of parameters. But, it is also quite complex.
• Python reference implementation of verifier. This is a true stand-alone verifier implemented from scratch in Python without any external dependencies. The goal of the implementation is to be a simple as possible. Currently, it only handles modular groups, it is slow, and it only verifies the core of the universally verifiable proof.
• More verifiers are currently implemented by other people and links will appear here when they are done.

Cooperation

• University of Surrey

  We are pleased to announce that the University of Surrey's team on the Trustworthy Voting Systems project, led by Dr James Heather and Prof. Steve Schneider, will be working with us to complete the Verificatum implementation. The aim of the Trustworthy Voting Systems project is to produce a practical and scalable implementation of the Prêt à Voter voting system, along with proofs that the system meets its security goals.

• Tel Aviv University and IDC Herzliya

  We are pleased to announce that the team behind the Wombat voting system led by Alon Rosen (IDC), Amnon Ta-shma (TAU), Ben Riva (TAU), and Jonathan (Yoni) Ben-Nun, have used Verificatum to implement the underlying mix-net.

• Ágora Ciudadana

  The team behind the Ágora Ciudadana project is working towards making Verificatum scale to massive and frequent elections by allowing Verificatum authorities to distribute the vote processing among multiple machines using Hadoop. Eduardo Robles Elvira founder of Wadobo SL is leading this effort. Ágora Ciudadana is a project (started by Partido de Internet, PDI) whose aim is to create a secure and scalable voting system with vote delegation support that can be used in a liquid democracy setup, where representatives act as mere proxy voters, voting in the representative chambers accordingly to what citizens previously voted over Internet.

Contributors

• Christopher Culnane. Pure Java sorting of large files and recursive copy code.
• Niko Farhi. Pure java elliptic curve code.
• Tim Lenneryd. Pure Java simultaneous exponentiation (first version).
• Freyr Sævarsson. Implementation of the provably secure Cramer-Shoup signature scheme.
• Eduardo Robles Elvira. Numerous bug reports and suggestions for improving the code.