Implementation Requirements for UK General Elections

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

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.: AAAAAA

4. UK General Election 2010

5. First-Past-The-Post (FPTP) 102 101 99 98 Labour Lib Dem Conservative Others

6. UK Election Reform

7. Alternative Vote (AV) 230 200 179 170 120 102 101 99 98 Alternative Vote is also called Instance Runoff Voting (IRV) sometimes Labour Lib Dem Conservative Others

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

9. 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.: AAAAAA

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

11. 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.: AAAAAA

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

13. Key Length ---- ECRYPT II

14. Key Length ---- NIST

15. 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.: AAAAAA

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.: AAAAAA

17. 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.: AAAAAA

18. 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.: AAAAAA

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!