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
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]
Because we care about
a meaningful result,
we’ve made auditing
very difficult.
21
We are left chasing
evidence of correctness.
Meanwhile we destroy
evidence on purpose.
22
Obtaining Evidence
Polling
Location
3 - Multiple poll watchers
competing affiliations
- No personal
4
Alice
electronic devices
at the polling station
- Logging all events
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.
The Effect of DREs
- More to audit
- Errors can have disproportionate effects
- Software is not just for speed/efficiency,
it becomes central for integrity.
Software
Independence
an undetected mistake in the
system does not cause an
undetectable error in the tally.
Secret Ballot vs.
Verifiability
Voting System
convince
Alice
Carl the Coercer
31
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
Public Ballots
Bulletin Board
Bob:
McCain
Carol:
Obama
Alice
32
Public Ballots
Bulletin Board
Alice: Bob:
Obama McCain
Carol:
Obama
Alice
32
Public Ballots
Bulletin Board
Alice: Bob:
Obama McCain
Carol:
Obama
Tally
Obama....2
McCain....1
Alice
32
Encrypted Public Ballots
Bulletin Board
Alice: Bob:
Rice Clinton
Carol:
Rice
Tally
Obama....2
McCain....1
Alice
33
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
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