Peter Ryan gave a talk at MIT on December 1, on “Advances in Verifiable Voting Schemes.” MIT has made a webcast of Ryan’s talk available (though the current video has a long introduction, be patient!).

Here’s the abstract of Ryan’s talk:

For centuries, the democratic process has largely been taken for granted and implicit trust has been placed in the paper ballot approach to casting and counting votes. In reality, the democratic process is one of considerable fragility, as the recent US presidential elections demonstrate.

For over a century, the US has been using technological approaches to recording and counting votes: level machines, punch cards, optical readers, touch screen machines, prompted largely by widespread corruption with paper ballots. All have been prey to various scams and forms of corruption or just plain malfunctions. Reports from Johns Hopkins and Princeton have demonstrated that many of the touch screen devices currently deployed in the US are wide open to virtually undetectable corruption.

In this talk I will discuss recent advances in cryptographically based, voter-verifiable schemes. These strive to provide high
assurance of accuracy whilst preserving ballot secrecy whilst requiring minimal trust in hardware, software, officials etc. Voters are able to confirm that their vote is included in the tally whilst having no way to prove to a third party how they voted, thus ensuring coercion-resistance.

In particular, I will outline the Prêt à Voter scheme and describe a number of vulnerabilities identified with the 2005 version. I will then describe enhancements designed to counter these vulnerabilities. These include the distributed generation of Prêt à
Voter ballot forms in encrypted form, on demand decryption and printing of forms, re-encryption mixes for tabulation, and a variant of Adida/Rivest off-line auditing.