The key problem in automated voter technology is ensuring voter anonymity — by unlinking ballots from citizens' identities — while still providing them a way to check that their ballots have been cast properly.

"Scantegrity gives voters a privacy-preserving receipt," [Essex] says. "It doesn't show other people how you voted, but it does allow you to have a way to check to ensure your vote gets counted."

The concept is similar to hotels that issue confirmation numbers, he says. "You can go online and look up your confirmation number, but it doesn't display your room number."

Another key security feature Scantegrity provides is software independence, Essex says. "This means if an error is made in the software, that mistake can't go through the process undetected. There's a software tool that does a cryptographic self-audit to verify computations."

Scantegrity is designed as an add-on to existing optical scanning voting systems such as Diebold, he says. But the difference is that mathematical formulas are used to generate the randomized confirmation codes issued to voters, and cryptographic principles are used in the software to tabulate and verify the results.

Police say the clip didn't lead to any witnesses coming forward, but the extra attention paid to the case because of the use of YouTube likely encouraged the suspect to turn himself in.
Hamilton police believe it's the first time law enforcement has used YouTube as a direct investigative tool.
Staff Sgt. Jorge Lasso, who made the decision to post the clip online, says the video had registered some 34,000 hits as of Thursday.