Upload
whitney-stevenson
View
215
Download
0
Tags:
Embed Size (px)
Citation preview
Implementation Requirements for
UK General Elections
Chris Culnane
James Heather
Steve Schneider
Sriramkrishnan Srinivasan
Zhe Xia (Joson)
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
1. First-Past-The-Post (FPTP)
or
Alternative Vote (AV)
UK General Election 2010
First-Past-The-Post (FPTP)Conservative
Labour
Lib Dem X
Others
Labour
102 101
Lib Dem Conservative
99 98
Others
UK Election Reform
Alternative Vote (AV)
Conservative 1
Labour 3
Lib Dem 2
Others 4
Labour
102 101
Lib Dem
Conservative
99
200
Alternative Vote is also called Instance Runoff Voting (IRV) sometimes
Others
98
120
179
230
170
2. A single constituency
80,000 voters
3. Multiple channel for vote casting
• Paper based surface
• Hybrid touch surface
4. Off-the-shelf hardware
5. Threshold trust• Threshold key generation
without a trusted dealer
• Threshold decryption
6. 128-bit security level
Key Length ---- ECRYPT II
Key Length ---- NIST
7. Time consideration• Ballot generation in 72 hours (1.2s /
ballot)
• Ballot tallying in 8 hours (0.3s / vote)
• Verification in 72 hours
8. Data size consideration• All vote information in a single DVD
(4.7GB)
• All the audit information in a single blue-ray disk (25GB)
9. Accessibility• 5-10 candidates
• No special knowledge needed
• Accessibility for disabled voter
10.Law and patent issues
• Candidate list in the alphabetic order
• Some building blocks may be patented
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)
Implementation Design
Election Manager
Candidate Names
Printers
Ballot SerialCandidate Names
Bulletin Board
Ballot Data
Tellers & Mix Servers
Polling Station Legal Guardian
Ballot Papers Sealed ID List
Booth
Signed Receipt
Ballot LookupVote Submission
Ballot Data, Vote
Thank you!