| > Because "scanning a QR code in an app" would lead to ... > 1) integrity loss, ie reduction of peers in the secret sharing concept. > 2) privacy loss, ie vote coercion, "show me you voted for our dear leader or something bad happens". Following your instincts instead of doing the work required to understand Prêt à Voter will lead you to that conclusion. Your instincts are wrong in this case. Neither of your claims are true. The first paragraph of the Wikipedia page makes that plain. It says in part: > In particular, Prêt à Voter enables voters to confirm that their vote is accurately included in the count whilst avoiding dangers of coercion or vote buying. In case you haven't thought about it, vote buying is the hardest problem to solve for secret ballots. It is hardest because both the voter and a malicious third party are working cooperatively to corrupt the system. If you come up with a system that prevents that, you've pretty much solved all retail voting attacks. Prêt à Voter makes a vote verifiable, while ensuring votes can't be sold. While you can't sell your vote with the typical implementation of Prêt à Voter, you can do it with your favoured paper ballot system: 1. Mallory obtains an authentic, blank ballot, and fills it in way he wants. Perhaps he does that by voting, pocketing the ballot paper, and putting the dummy in the ballot box. 2. Mallory gives the pre-filled ballot to a voter willing to sell his vote for an agreed sum outside the voting booth, where the transaction can't be detected. The voter isn't given his payment yet. 3. The voter goes into the secure voting place and is given a blank ballot. In the privacy afforded to him to cast a secret ballot he pockets the blank ballot, replacing it with the pre-filled ballot given to him by Mallory. 4. The voter casts the paid for vote. 5. The voter meets with Mallory in their secret spot, hands over the blank ballot and gets paid. Rinse, lather and repeat all the way to winning the election. If you haven't seen that little caper described before you will find it surprising. I did. But it is nowhere near the surprise you will get from spending the time to learn how Prêt à Voter achieves what appears to be impossible. |
This is from the actual paper, not wikipedia:
> C. Audit of ballot forms Voters may wish to check that the order of candidates claimed to be encrypted on the right-hand side does indeed correspond to the list printed on the left-hand side. If this were not the case then a vote cast for one candidate may be considered after decryption as a vote for a different candidate. To provide such reassurance, voters may elect to ‘audit’ a ballot form. This involves removing the left-hand side of the ballot form, and asking the system to decrypt the candidate list from the onion on the right-hand side. The voter can then check that the decrypted list matches the list of candidates printed on the left-hand side. In principle, this audit can be carried out as often as the voter wishes. This gives the voter confidence that the ballot forms have been correctly constructed.
> However, the voter is not allowed to cast a vote on a decrypted ballot form. Once the candidate list associated with a onion is known, vote privacy, and hence resistance to coercion and vote-selling, is lost. The audit process gives an individual voter confidence that the ballot forms are correctly constructed, but does not allow her to check the ballot form that she is using to cast the vote.
What I said in GP is that you can't verify WHAT you voted for AFTER the fact, because the concept of coercion hinges on being able to threaten or pay for something the victim can provide. It's a logical proof, you can't design that away. I'm not saying it's not a valid trade-off.