Maryland Town Tests New Cryptographic Voting System

ceswiedler writes "In Tuesday's election voters in Takoma Park, MD used a new cryptographic voting system designed by David Chaum with researchers from several universities including MIT and the University of Maryland. Voters use a special ink to mark their ballots, which reveals three-digit codes which they can later check against a website to verify their vote was tallied. Additionally, anyone can download election data from a Subversion repository and verify the overall accuracy of the results without seeing the actual choices of any individual voter."

Comments

Chaum's system is very cool

[swillden]

It does what many people would have said is impossible: It allows voters to verify that their votes were cast and counted correctly, but does not provide them with any way to prove to anyone who they voted for. An audit trail, without opening the door to coercion. This is a major improvement over traditional voting technologies.

Re:Chaum's system is very cool

[zn0k]

"But voters can't be sure just by looking at their ballot image that the system interpreted the codes accurately to apply the vote to the correct candidate. That's where independent auditors come in."

TFA to the rescue.

Re:Chaum's system is very cool

[nacturation]

but does not provide them with any way to prove to anyone who they voted for.

But can I check to make sure not just that my vote "was counted" but that my vote was for the right person?

Yes:

Voters make their selections on a paper ballot using special pens with ink designed by Chaum. When a voter fills in an oval on the ballot, the ink in the pen, which is similar to the yellow ink in highlighter pens, reacts with invisible ink in the oval and turns most of the oval black. At the same time, a unique three-letter code pre-printed on the ballot inside each oval is revealed to the voter.

After making their choices, voters use a form to write down the serial number that is printed on their ballot as well as the three-digit codes inside the ovals they’ve chosen. The codes are generated cryptographically and are different on every ballot to prevent someone from deciphering the voter’s choices and engaging in vote-buying.

So that's the "verify that it was recorded correctly" part. For the "verify it went to the right candidate part":

Voters can also see, based on the three-letter codes, that the system seems to have recorded their selections accurately. But voters can’t be sure just by looking at their ballot image that the system interpreted the codes accurately to apply the vote to the correct candidate. That’s where independent auditors come in.

Scantegrity uses a process called “zero knowledge” that allows skilled, independent auditors to verify that the codes result in votes going to the right candidates, without actually revealing an individual voter’s selections.

I don't know how it works exactly, but I assume it's similar to a public/private keypair given that they describe it as a cryptographic mechanism. The interesting thing is that anyone can audit the election results to demonstrate that votes were counted accurately: https://scantegrity.org/svn/data/takoma-nov3-2009/PUBLIC/PUBLIC/

Re:Interesting, but...

[noundi]

but are we that concerned about votes not being counted?

I was about to write a long reply about how democracy depends on the fact that bla bla bla... and how you cannot trust people, especially what in politics and bla bla bla... but you asked a simple question so I'll give you a simple answer:
 
  Yes.

The Real question...

[gd2shoe]

Ok, so this system proves that your vote reached the tally server, but how does it prove that your vote is actually in the total?

I'm serious. Just because your vote wasn't lost, doesn't mean it was counted. This helps guard against grievous mistakes, not against wholesale fraud.

Re:The Real question...

[WaywardGeek]

Ok, so this system proves that your vote reached the tally server, but how does it prove that your vote is actually in the total?

Good question. They use "zero knowledge" proofs:

"Scantegrity uses a process called “zero knowledge” that allows skilled, independent auditors to verify that the codes result in votes going to the right candidates, without actually revealing an individual voter’s selections."

It's super-cool stuff every slashdot geek needs to know. So, this allows us to insure our vote was counted without enabling us to sell our votes. Very cool! However, it still not fool-proof. A friend of a friend of mine has gotten so worked up over an election that she went to the polls early, and often, and voted for her whole extended family. Without requiring photo-IDs, it's really easy to do. Every show up to a poll and see your name has already been crossed off?

Web Logs?

[icebike]

Quoting TFA

"When polls close, voters can go to the election office website, type in their ballot serial number and see a rendition of a ballot, showing the three-digit codes for their votes. This way voters can be assured that their ballot was included in the final tally."

One would hope there are no web logs kept, because simply checking your ballot would reveal your identity, and someone is sure to wrangle a subpoena for that.

Re:Web Logs?

[BasilBrush]

Even simpler. Have the system display ranges of ballot numbers and codes, not just single ones. If I have serial number 12345 and I click on a link to examine papers 12300-12399, the eavesdropper doesn't know which of the 100 ballots displayed I checked.

Great on paper - but in real life?

[fremen]

This system assumes three things:

• Everyone participates - voters have to validate their vote afterward to make sure it's still correct.
• Everyone is perfect - people who incorrectly cast their vote will always suspect fraud, calling the entire election into question.
• Everyone is sane - individual voters do not lie about about their vote to game the system, cast doubt on the election, etc.

Re:Great on paper - but in real life?

[CannonballHead]

With perfect, sane, always-participating people, who needs a government? ;)

Re:Great on paper - but in real life?

[swillden]

This system assumes three things:

• Everyone participates - voters have to validate their vote afterward to make sure it's still correct.

Per TFA, only about 5% of participants have to validate their vote afterward to assure the election's integrity to within normal margins. Also, exit polls in the Maryland town showed that about 30% of voters copied down their validation info. If a third of them bother to go online to check their ballots, that will be double the required participation.

Everyone is perfect - people who incorrectly cast their vote will always suspect fraud, calling the entire election into question.

Individuals will always have suspicions, but unless there is a widespread pattern of "errors", rational voters will be able to have greater confidence than they do in any other system. Unlike any other system, this one actually provide a way where lost or altered ballots have a chance of being discovered.

Everyone is sane - individual voters do not lie about about their vote to game the system, cast doubt on the election, etc.

Again, isolated cases will occur, but that happens regardless. In the absence of significant numbers of reports from generally honest and reliable people, then we'll have more confidence in the accuracy of the vote than any other system can provide.

Basically, your objections boil down to "Nothing is perfect". Well, duh. But it doesn't have to be perfect, it just has to be better. And it is.

Re:Cost of printing?

[Areyoukiddingme]

The printing of ballots in most jurisdictions already falls under the category of "custom" printing. Ballots are unique every election (despite an enormous preponderance of re-elected incumbents). Ballots can vary from precinct to precinct to the extent that, in theory, no two precincts are alike, because of differing jurisdictions (different counties, different cities, different municipalities of various flavors). That combined with the relatively low number of copies made for any particular precinct means that the cost of printing each one uniquely isn't different. The printing won't be done by high-speed high-volume expensive-setup full-color color-separated presses anyway. It'll be done by laser printer or thermal printer or such.

Re:Interesting, but...

[NoYob]

but are we that concerned about votes not being counted?

I was about to write a long reply about how democracy depends on the fact that bla bla bla... and how you cannot trust people, especially what in politics and bla bla bla... but you asked a simple question so I'll give you a simple answer: Yes.

To most people it's only "Yes" if the election doesn't go their way.

Re:Interesting, but...

[swillden]

I'm far more concerned about phantom votes being counted than real votes not being counted.

Both are real issues. There are plenty of examples of ballot boxes getting "lost", so those are real problems. Dead people voting, multiple votes, systematic exclusion of voters (not losing their ballots, but preventing them from voting), all of these things are problems.

This system doesn't solve all of those other problems, but it does solve the problem of votes getting lost, altered or counted incorrectly. And it does it in a mathematically-provable fashion.

See the paper.

Re:Interesting, but...

[vilhuber]

Not sure I'm reading you properly, but this system allows you to verify your vote was COUNTED, nothing more. You can't show or prove to anyone HOW you voted, just that you did and that your vote is in the tally AS CAST.

This is huge. I've been waiting for chaum's election stuff to actually be used for quite some time now. I'm hugely excited.

It's Takoma Park, folks

[R2.0]

This is the place they like to call the "Berkeley of the East". It's so liberal it's almost a parody. I think the MD Democratic Party keeps it around as a pure strain in a petri dish so that they can pretend they are also liberal.

It also means that if Takoma Park thinks it's a good idea, everyone else in MD will think it's a joke and ignore it.

Re:Interesting, but...

[Mr2001]

Not sure I'm reading you properly, but this system allows you to verify your vote was COUNTED, nothing more. You can't show or prove to anyone HOW you voted, just that you did and that your vote is in the tally AS CAST.

Er, unless I'm missing something, it's still possible to prove to someone how you voted. You just need to take a picture of your ballot, showing that the code "JX" is in the bubble next to "John Smith" -- this is pretty easy if you're voting absentee, or if you aren't frisked and metal-detected on your way into the voting booth. When the local thug comes around to verify your vote, you show him the picture and your ballot ID, and then he goes online to make sure that your ballot ID and your "JX" vote are in the system.

Re:This allows vote buying!

[dch24]

There is no way to connect your codes on your receipt (two letters each) with the name of the candidate. Every ballot uses different codes.

The website only shows you: serial number 1234567 voted for these codes: two-letters two-letters two-letters, etc.

Re:Interesting, but...

[Mr2001]

But it doesn't scale, imho. Everybody voting absentee in a district? Red flag.

In the state where I live, 37 of the 39 counties have nothing but absentee voting. You can go to the election office to drop off your ballot, but everyone gets a ballot weeks in advance.

On the other hand, that means we've already conceded the battle against this sort of voter intimidation/bribery. The thug can just watch you fill out the ballot. Hasn't been a problem in practice, though... yet.

Digital camera in the booth too often? (Some people are savvy enough to turn off the sounds, and some people are savvy enough to hide their camera. But most people are not.) Red flag. Game over.

I don't know about your camera, but mine is cleverly hidden inside my cell phone. Doesn't take much savvy to get one of those, and before long, almost everyone will have a 3+ megapixel camera in their pocket -- if we're not there already.