• Calendar

February 2, Tuesday
12:00 – 13:30

A democratic election is a classic example of a task in which multiple adversarial parties must collaborate and agree on an outcome. Traditional election systems (such as the one used in Israel) employ various means to ensure that the result will be accurate even if some of the people involved are corrupt or dishonest. However, the final tally is only as trustworthy as the people who count the votes. Even in the most secure systems these are usually fairly small committees. If an entire committee colludes, they can manufacture their own results. Even worse, depending on the exact setup, it may be feasible to stuff ballot boxes, destroy votes or perform other manipulations.

Using cryptographic techniques, it is possible to design a fair voting system whose correct operation can be verified by anyone, while still retaining ballot secrecy. This can be done even if the computers used to run the election are untrustworthy.

In the talk, I will briefly survey the techniques used to accomplish this and present in more detail examples with some unique properties, such as a practical solution for securely tallying Single Transferable Vote elections (a ranked voting system that is used in Australia, Ireland and Malta, among others). The talk will contain any necessary cryptographic background.

If time permits, I will also give a brief introduction to the Qilin project, a Java SDK for rapid prototyping of cryptographic protocols. The purpose of the Qilin project is to make it easier to build practical implementations of new cryptographic protocols, such as those for cryptographic voting. To this end, the API attempts to use the concepts and language from the theory of cryptography. The SDK is open-sourced and available on the web.

Based on joint works with Moni Naor and with Josh Benaloh, Lee Naish, Kim Ramchen and Vanessa Teague.