Yes, Ka-Ping Yee is right my new attack on Rivest scheme can be argued not "really" to be an attack because (a) it is a 3-way collusion (voters, vote-buyers, and govt) and my Rivest description only claimed it to be secure against ONE of these players, not all 3 in collusion, and (b) those voters gave up their receipts, like driving without seatbelt on, so why should it work anymore?
However, I feel that (1) THIS collusion happens to be pretty likely-sounding, whereas the usual point with large collusions is they are supposed to be unlikely. (2) It doesn't actually feel like a large collusion since while millions could be involved, only a few need to be in on the secret and the rest could be entirely innocent, or at least could justifiably claim they were. I mean, it is like you give a bank robber driving directions to a bank that you dislike, whie having little or no certainty it was a bank robber. Is that a "collusion"? (3) When you leave off your seatbelt, you know you are taking a risk. When you give up your receipt to an organization on your side, you know you are being protected, and indeed (with the fraud scheme) in fact over-protected (you will be miraculously granted 3 votes instead of just 1). So that analogy doesn't make me happy. (4) Sure this would be out-and-out fraud, but the whole damn point of Rivestism, was it was supposed to PROTECT us against fraud (assure it would be detected, anyhow). If it does not, as here, then it failed. ------ Next, Juho Laatu's idea sounds a lot more promising: >The voting machine could make some additional copies of the receipts >and distribute them to other voters. Then voters could not be sure >that they have the only copy of the receipt. Aahh. This, I like. Let us say, 1% of all voters, randomly selected, are "lucky voters" who get an extra receipt handed to them from somebody else's vote. That is big protection against the attack I outlined. However, if the machine can do that, then it is risky the machine can remember stuff, or risky the machine could permit the govt to see what got copied, both of which would be bad and would enable cheating. Still, this sounds like a least the beginning of an excellent idea for saving Rivest's skin... OK (variant): the machine (let us say) is dumping all the ballots random-order into a big bin. Each voter rolls 2 dice, and if gets 6&6 is selected to be a lucky voter who gets to pull a ballot out of the bin randomly and get a copy of it. That way, no memory goes on, and randomness is self-evident. Hey, *that* really does seem to fix it. ---------- You know, this whole development is just the weirdest experience. Alice in Wonderland goes voting. Lewis Carroll, you know, was a prominent voting researcher. -- Warren D. Smith http://RangeVoting.org <-- add your endorsement and math.temple.edu/~wds/homepage/works.html ---- election-methods mailing list - see http://electorama.com/em for list info
