1. Implementation Requirements for UK General Elections TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A Chris Culnane James Heather Steve Schneider Sriramkrishnan Srinivasan Zhe Xia (Joson)

2. Implementation Requirements First-Past-The-Post (FPTP) & Alternative Vote (AV) Focus a single constituency (around 80,000 votes) Multiple channel for vote casting (paper ballot & touch surface) No special equipment needed (off-the-shelf hardware) Threshold trust (distributed trust at least) 128-bit security level Ballot generation phase in 72 hours Ballot tallying phase in 8 hours (10pm – 6am, 0.3s/vote) Auditing of the ballot tallying phase in 72 hours All votes information in a single DVD (4.7GB) All the audit information in a single blue-ray disk (25GB) Accessibility Law issues

3. 1. First-Past-The-Post (FPTP) or Alternative Vote (AV) TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

4. UK General Election 2010

5. First-Past-The-Post (FPTP) Conservative Labour Lib DemX Others Labour 102101 Lib DemConservative 99 98 Others

6. UK Election Reform

7. Alternative Vote (AV) Conservative1 Labour3 Lib Dem2 Others4 Labour 102101 Lib DemConservative 99 200 Alternative Vote is also called Instance Runoff Voting (IRV) sometimes Others 98 120 179 230 170

8. 2. A single constituency 80,000 voters TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

9. 3.Multiple channel for vote casting Paper based surface Hybrid touch surface TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

10. 4. Off-the-shelf hardware TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

11. 5.Threshold trust Threshold key generation without a trusted dealer Threshold decryption TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

12. 6. 128-bit security level TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

13. Key Length ---- ECRYPT II

14. Key Length ---- NIST

15. 7.Time consideration Ballot generation in 72 hours (1.2s / ballot) Ballot tallying in 8 hours (0.3s / vote) Verification in 72 hours TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

16. 8. Data size consideration All vote information in a single DVD (4.7GB) All the audit information in a single blue-ray disk (25GB) TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

17. 9.Accessibility 5-10 candidates No special knowledge needed Accessibility for disabled voter TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

18. 10.Law and patent issues Candidate list in the alphabetic order Some building blocks may be patented TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A A A A

19. Building Blocks Prêt à Voter ballot form (uniform ballot for both FPTP and AV) ElGamal with re-encryption mixes (no homomorphic tally) Verifiable shuffle (Randomised Partial Checking) Threshold key generation without a trusted dealer Verifiable decryption (Chaum-Pedersen proof)

20. Implementation Design

21. Thank you!