David Chaum and his team have just released Punchscan v1, the first open-source implementation of a truly verifiable voting system. Like other voting systems in its class (there aren’t that many), it allows for truly open auditing and voter verification. And it’s extremely misunderstood. The Slashdot thread is way off the mark, so I thought I’d revisit the Punchscan FAQ to help clear things up.
Q: So, I can sell my vote?
A: No, the votes are encrypted.
Q: But the voting system knows how I voted?
A: No, the votes are encrypted.
Q: So, if my vote is encrypted, how can I trust the machine to encrypt it correctly?
A: You don’t trust the machine. You mathematically verify the proof it gives you that it prepared the ballots correctly.
Q: Well, then it only verifies the ballot casting, but the counting machine could still produce any result it feels like!
A: Actually, no, because the counting machine also provides a proof of how it counted the votes. Anyone can check this proof. The check is end-to-end: all the way to the final tally.
Q: Listen, I was a comp sci major, and if the computer is compromised, then it can lie to you about what it’s doing, including these so-called proofs.
A: Not in this case, because the machines cannot cheat when providing the proof: the result is guaranteed by mathematics, not by trust.
Q: But that doesn’t make sense. If I’m convinced of how I voted, then I can obviously sell my vote.
A: No, not with this kind of system. It sounds impossible, but it’s not. It has to do with zero-knowledge proofs.
Q: That’s crazy talk.
A: Read the FAQ, and the detailed papers.
This isn’t your average voting system. Read the papers. Chances are, you’ll find out that what seemed impossible in fact isn’t.
Benlog 
Comments
2 responses to “The Punchscan FAQ Revisited”
Excellent write-up!
You might want to play up the fact that Punchscan is an open system that has been reviewed by secuity experts worldwide. Perhaps all the experts in the world are wrong, but anyone who believes that ought to explain where they all went wrong.
&ers
Excellent write-up!
You might want to play up the fact that Punchscan is an open system that has been reviewed by secuity experts worldwide. Perhaps all the experts in the world are wrong, but anyone who believes that ought to explain where they all went wrong.
&ers