1. Demonstration of the Version 1 Prototype of Prêt à Voter Steve Schneider, Chris Culnane University of Surrey SecVote, Bertinoro 3rd September 2010 TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A AAAA A A

2. Prêt à Voter Prototype Version 1 Entry in VoComp 2007 Starting point system for the Trustworthy Voting Systems (TVS) project (Surrey, Birmingham, Luxembourg) 2009-2013 Used for focus groups Original versions for STV (USSU, VoComp) More recent version for FPTP Hardware: off the shelf (laptop; printer/scanners) Version 2 to be produced during the TVS project…

3. A brief guide to voting with Prêt à Voter TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A AAAA A A

4. 1. Alice 2. Bob 3. Crystal 4. Diane 5. Elaine Casting a vote Place X against desired candidate. Separate left hand side. Destroy left hand side. Cast (scan) vote and get signed. Take receipt home. 6QakL5sR signed

5. Bulletin Board publishes the ballots cast. Public bulletin board of votes cast. x x x x ifde w8u jt1e 6Qak Voter’s receipt Voter receipts prevent election officials from discarding or altering votes. 6QakL5sR

6. Auditing ballot forms A voter might have the following concern: –Suspect ballot forms. –What if the encrypted order doesn’t match the printed order? This should not happen if the ballot forms are correctly constructed. But how can the voter be satisfied of this? 1. Alice 2. Bob 3. Crystal 4. Diane 5. Elaine 42513 6QakL5sR A vote for Crystal would be counted for Alice

7. Auditing the ballot forms To audit a ballot form – a voter can have it decrypted without voting, and check that the result matches the printed candidate order. In principle the crypto can be checked (randomness exposed) We introduce the option to audit as part of the voting process. Voters can do this with as many forms as they like (in principle!) This gives them confidence that the ballot forms are correctly constructed. 1. Alice 2. Bob 3. Crystal 4. Diane 5. Elaine 42531 6QakL5sR

8. A Ballot Form

9. System Demo To Vote –Mark X against your chosen candidate –Remove and destroy the left-hand side –Scan the right hand side –Obtain your (newly printed) receipt. [Also enables check of scan.] To Audit –Do not mark any X –Remove the left-hand side but do not discard it –Scan the right hand side - the blank ballot triggers an audit –Check that the order produced matches the order left-hand side To Check the receipt (and eventually the result) with your laptop –Log into the bulletin board. For this demo it is at: SSID: clone (no password, no encryption) Go to http://192.168.2.99/pav/receiptlookup.phphttp://192.168.2.99/pav/receiptlookup.php –Submit your serial number and compare against your receipt