Threat Level has an article discussing the security of one particular style of electronic voting machine. The findings of a test:
With nothing more than a magnet and an infrared-enabled Palm Pilot or cell phone they could easily read and alter a memory device that is used to perform important functions on the ES&S iVotronic touch-screen machine—such as loading the ballot definition file and programming the machine to allow a voter to cast a ballot. They could also use a Palm Pilot to emulate the memory device and hack a voting machine through the infrared port (see the picture above right).
They found that a voter or poll worker with a Palm Pilot and no more than a minute’s access to a voting machine could surreptitiously re-calibrate the touch-screen so that it would prevent voters from voting for specific candidates or cause the machine to secretly record a voter’s vote for a different candidate than the one the voter chose. Access to the screen calibration function requires no password, and the attacker’s actions, the researchers say, would be indistinguishable from the normal behavior of a voter in front of a machine or of a pollworker starting up a machine in the morning.
The attack they describe is significant because the researchers’ description of how an intentionally miscalibrated machine would function—that is, prevent a voter from voting for a certain candidate—is precisely how some voters described the ES&S machines were acting in a controversial Florida election last year.
Maybe I’m justified in my preference that I vote by making a mark on a piece of paper, which is kept available in a box someplace?