26. Wooten got the news from his wife, Roxanne,
who went to City Hall on Wednesday
to see the election results.
quot;She saw my name with zero votes by it.
She came home and asked me if
I had voted for myself or not.quot;
10
55. But Secrecy is Important.
Secret Ballot implemented in Chile in 1958.
“the secrecy of the ballot [...] has
first-order implications for resource
allocation, political outcomes, and social efficiency.”
[BalandRobinson 2004]
56. Because we care about
a meaningful result,
we’ve made auditing
very difficult.
21
57. We are left chasing
evidence of correctness.
Meanwhile we destroy
evidence on purpose.
22
60. Obtaining Evidence
Polling
Location
3 - Multiple poll watchers
competing affiliations
- No personal
4
Alice
electronic devices
at the polling station
- Logging all events
62. Fragmented, Adversarial
and Indirect
- each piece of evidence covers
a small segment of the chain.
- attacker knows the checks, and can try to
sneak in where the chain is not covered.
- to maintain security and for practical
purposes, the evidence is very indirect.
63. The Effect of DREs
- More to audit
- Errors can have disproportionate effects
- Software is not just for speed/efficiency,
it becomes central for integrity.
64. Software
Independence
an undetected mistake in the
system does not cause an
undetectable error in the tally.
65. Can we get
more direct,
more end-to-end
evidence?
66. Secret Ballot vs.
Verifiability
Voting System
convince
Alice
Carl the Coercer
31
67. Secret Ballot vs.
Verifiability
Voting System
convince
Alice
Carl the Coercer
[Chaum81], [Benaloh85], [PIK93], [BenalohTuinstra92], [SK94], [Neff2001], [FS2001],
[Chaum2004], [Neff2004], [Ryan2004], [Chaum2005]
Punchscan, Scantegrity I & II, Civitas, ThreeBallot, Prêt-à-Voter, Scratch & Vote, ...
31
68. Public Ballots
Bulletin Board
Bob:
McCain
Carol:
Obama
32
69. Public Ballots
Bulletin Board
Bob:
McCain
Carol:
Obama
Alice
32
70. Public Ballots
Bulletin Board
Alice: Bob:
Obama McCain
Carol:
Obama
Alice
32
71. Public Ballots
Bulletin Board
Alice: Bob:
Obama McCain
Carol:
Obama
Tally
Obama....2
McCain....1
Alice
32
72. Encrypted Public Ballots
Bulletin Board
Alice: Bob:
Rice Clinton
Carol:
Rice
Tally
Obama....2
McCain....1
Alice
33
73. Encrypted Public Ballots
Bulletin Board
Alice: Bob:
Rice Clinton
Carol:
Ali Rice
ce
ver Tally
ifies
he
rv Obama....2
ote
McCain....1
Alice
33
74. Encrypted Public Ballots
Bulletin Board
Alice: Bob:
Rice Clinton
Carol:
Ali
ce Rice ta lly
ver e
thTally
ifies rifies
ve
he
rv eryone
ote E v Obama....2
McCain....1
Alice
33
