The Prêt à Voter (PAV) electronic voting system, created by Peter Ryan (Newcastle Technical Report TR864 at WITS'05) and later enhanced by Peter Ryan, Steve Schneider and David Chaum (Newcastle Technical Report TR880 at ESORICS 2005), is designed to provide secure and auditable elections using cryptographic techniques. It provides an excellent trade off among security, versatility and usability.

Security

The security of the Prêt à Voter system is not dependent on election authorities who run the election or any equipment used in the election, but depends only on hard cryptographic problems. In PAV, the voter's anonymity will be guaranteed. Not only will voter's choice information be kept secret from others, but also voters can not prove to others how they have voted, thereby preventing vote coercion, intimidation, and ballot selling.

Furthermore, the whole election processes are designed to be transparent and auditable. When using the Prêt à Voter system, each voter will be provided with a receipt, which does not allow voters to prove how they have voted, but enables them to verify that their votes have been properly recorded by the system. In addition, any interested party can verify the correctness of the final result. If the adversaries cannot break the hard cryptographic problems, any malicious behaviour during the election processes will be detected with overwhelming probability.

Although trust is necessary in all election systems, the trust in PAV system can be clearly identified and distributed in threshold fashion among several parties with different interests.

Versatility

Another advantage of the Prêt à Voter system is its versatility with respect to different electoral systems. It not only handles binary voting method, such as FPTP elections, but also can be used in ranked voting elections, such as condorcet elections, Borda Court elections and STV elections.

Usability

The Prêt à Voter system is easy to use, both for voters and for the election authorities. Although cryptographic techniques are involved in the PAV system, they are transparent to voters. The ballot form will be familiar to ordinary voters and they can use the system without special knowledge. Besides, voter's task has been reduced to the minimum to cast a vote. To run an election using the Prêt à Voter system, the election authorities can set-up everything in an acceptable timescale, no expensive or special equipment is needed.

Our Implementation of the Prêt à Voter System

Now the Prêt à Voter system has been developed from a description to an implementation. The Electronic Voting Group (EVG) of University of Surrey has made a complete implementation of the system and trialled it in the University of Surrey Students' Union (USSU) Sabbatical Elections 2007. This is the first time the full system was demostrated in public.