 From a security standpoint, what distinguishes computerized voting systems from traditional systems is not that computers are easier to compromise, but that the consequences of compromise can be so much more severe. Tampering with an old-fashioned ballot box can affect a few hundred votes at most, but injecting a virus into a single computerized voting machine can potentially affect an entire election. Two weeks ago, my colleagues Ari Feldman and Alex Halderman and I released a detailed security analysis of this machine, the Debald AccuVote TS, which is used in Maryland, Georgia and elsewhere. My written testimony summarizes the findings of our study. One main finding is that the machines are susceptible to computer viruses that spread from machine to machine and silently transfer votes from one candidate to another. Such a virus requires moderate computer programming skills to construct. Computing it requires access to a single voting machine for as little as one minute. I will now demonstrate this using a virus we constructed in our laboratory. We've set up here a simulated election for president between George Washington and Benedict Arnold. It's election day morning and we just opened the polls. No votes have been cast yet. I'll start by casting the first vote. When I checked in at the polling place at the front desk, the poll workers gave me this voter card, which I now insert into the machine. I press the start button and I choose to cast my vote for George Washington. The machine asks me to confirm my choice and I confirm my choice and cast my ballot. The second vote is similar. I insert another voter card. I choose George Washington again and again I confirm and cast my ballot. The third voter inserts another voter card and votes again for George Washington. The correct vote counted this election obviously is George Washington 3, Benedict Arnold 0. Now it's the close of election day. A poll worker inserts a special supervisor card into the machine, enters a PIN code and tells the machine to end the election and tally the votes. The machine will now print out a paper tape summarizing the ballot count. When I cast my votes earlier, my choice of candidate was recorded in the machine's electronic memory. This record of my vote was invisible to me. I had no way of verifying whether it was recorded correctly or whether it was changed after it was recorded. In this machine, the records were modified by our virus. This paper tape printed out by the machine reports the election's result and it shows George Washington with one vote and Benedict Arnold with two.