On Sat, 2006-11-25 at 21:40 -0500, Ryan Lortie wrote: > Hello. > > This falls under the category of "concerns about the election process". > It's a bit of a nit-pick. > > I'm writing about two concerns. The two concerns are secrecy of the > vote (nobody can discover who I voted for) and security of the vote > (nobody can tamper with the results without being discovered). > > --- > > I will first discuss security. This issue is easy to fix and should be > fixed for the next elections. > > It is clear that an attempt has been made toward security. The use of > anonymous tokens are provided to allow each concerned voter to be sure > that their vote has been counted properly. > > - step 4 is a confirmation that your vote has been accepted and gives > you the anonymous token that will enable you to verify your vote. > > This is insecure. > > As a voter, how do I know that my "token" isn't just a deterministic > hash of my choices? The people running the election could then easily > just publish my choices along with this token once for every person who > chose the same way that I did. Essentially, I don't know if my vote is > really my vote at all, so I have no reason to believe that my vote has > been counted. Hashes are not created with your choices. It's a random hash which is used for voter to check his/her vote after results are announced. It's only the voter who knows that the hash depends on him or her. Apart from that even memberhip-committee members has no way to know that ie. Ryan has this hash. > > The only way of discovering this would be to talk with others about my > choices and even then it's only a single collision which could easily be > put off as voter error. Discovering the corruption of those holding the > voting process would require a massive public disclosure of who everyone > voted for. After results are announced, there will be a page listing all votes counted with hashes and votes used with that hash. Since you had already noted your hash somewhere, you will be able to check if your vote is counted and has correct votes. If not you can challenge elections. > > All reasonably secret voting systems must dismiss single users claiming > errors (since otherwise someone could change their mind and cause the > election to be held again). It should take a large number of people > claiming inconsistencies in order for real doubt to be cast on the > process. Once you have voted you can't change your vote. And your vote token is not valid anymore. If you believe that you did not vote and your token is invalid, you can contact elections gnome org to report this issue. > Now of course, I trust those running the elections. It's just that if > you are going to go to the effort of attempting to prove that the > process is secure against tampering then you should actually prove it. > A secure process would be to allow the voter to provide their own > anonymous token. This token could be any string or could be limited to > a hexadecimal number of an exact (reasonable) size. To make the process > easier, a Javascript "Generate" button could be used to generate this > random number. The source of the Javascript could be inspected, and for > the truly paranoid there would still be the possibility of entering your > own token. The thing is, process of creating voting tokens are similar, that token is created by automatic script on server elections run. But there's no connection b/w this token and your vote. That token just enables system to let a specific email to be able to vote and its use ends there. By making voters to create their own token to vote, we have to store e-mail addresses which has voted, which is less secure I guess. If you can elaborate more on it, I think I can respond better. > > The voter could then be sure that with a vanishingly low chance of a > collision, that their vote is in fact their vote. Hashes are randomly generated md5 hashes, and collisions are really less likely. > > --- > > The second problem is secrecy. This problem is a lot more difficult to > fix in a reasonable manner and maybe should not be fixed at all. The > problem stems from the fact that the voting web application could > trivially be augmented to create a log of each voter and their choices. It does not log voters, it just logs hashes as I stated above. It has to keep votes somehow to count it, though. > > A possible workaround for this limitation is the idea of a > blinded-signature scheme. Under this scheme, it is possible to have an > entity sign a document without being able to view it. The voting > process then proceeds something like this: > > A voter generates a random voting token of a specific format (in this > case, it would likely be the same random token as used in the vote > security process outlined above). They "blind" this token and send it > along with traditional credentials (like email address and voting key, > or possibly PGP signature from their email address) to a ballot signing > authority. The ballot signing authority ensures that this is the only > signing request that the user has made, signs their ballot and returns > it to them. Agreed, however this puts more technical barrier to vote, which might cause some not being able to vote at all. I'm totally into using PGP keys to authorize members, e-mail is insecure for that, but we currently just "trust". Sometime in future we should lower this barrier with some tools and switch to PGP keys, as cvs accounts switched. > > The token is of a specific format to prevent certain types of attacks in > which it might be possible (depending on the blinding scheme used) to > obtain a signature that is valid for multiple messages. > > The signing authority can log all of the ballets that it has signed (and > in fact it probably should, to allow recovery of lost ballots). > The voter then "unblinds" their ballot, receiving their original voting > token. They vote with this token. The election is held by possibly the > same person who did the blind signature. > > Because of the blinding process, it is possible for the people holding > the elections to ensure that the ballot is legitimate but absolutely > impossible to link it with a specific person. The people holding the > election record each unique token used to vote in order to ensure that > multiple voting does not occur. > > I've been intentionally vague about the specific algorithms used to do > blind signatures because there are a lot of them. The entire process is > also explained in much more detail here: > http://en.wikipedia.org/wiki/Blind_signature > > --- > > These are my two concerns. Please take the first half of this email > very seriously and the second half as a pie-in-the-sky idea that might > be nice eventually if somebody has a lot of time. It's only recently > that GNOME has had anonymous voting at all, so voter secrecy is a > somewhat less important issue than the security of the vote. > > I'd like to take a moment here to acknowledge Baris and everyone else > who has been involved in the election process this year. Thanks guys. > Without you, there wouldn't even be a vote to speak of. Thanks you very much for your feedback, be sure that it will be taken into consideration. > > Cheers > _______________________________________________ > membership-committee mailing list > membership-committee gnome org > http://mail.gnome.org/mailman/listinfo/membership-committee
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