Diebold Election Systems plans to make changes to its electronic voting machines, following the disclosure of a number of serious security flaws in the systems.

On Thursday, the voting watchdog organisation Black Box Voting published a report (PDF) detailing how Diebold's TS6 and TSx touch-pad voting machines could be compromised by taking advantage of "backdoor" features designed to allow new software to be installed on the systems.

Finnish security researcher Harri Hursti, discovered backdoors in the boot loader software, in the OS, and in the Ballot Station software that it runs to tabulate votes.

Rear-access technology

"These are built-in features, all three of them," said Black Box Voting Founder Bev Harris. If a malicious person had access to a Diebold machine, the back doors could be exploited to falsify election results on the system, she said.

A Diebold spokesman did not dispute Hursti's findings, but said that Black Box Voting was making too much of the matter because the systems are intended to remain in the hands of trusted election officials.

"What they're proposing as a vulnerability is actually a functionality of the system," said spokesman David Bear. "Instead of recognising the advantages of the technology, we keep ringing up 'what if' scenarios that serve no purpose other than to confuse and in some instances frighten voters."

Key vote

Nevertheless, Diebold plans to address the issue in an upcoming version of the product, which will use cryptographic keys to ensure that only authorised software is installed on the machine, Bear said. He could not say when this feature would be added, but said that it could be available in time for the November 7 general election in the US.

After the November 2000 presidential election exposed flaws in traditional paper ballots, many states have rushed to adopt electronic voting systems. But computer experts have pointed out numerous security flaws in these machines, and some consumer groups have called for them to be dropped altogether.

Attack threat upgrade

These latest set of flaws are the most serious voting machine flaws yet reported, according to Ed Felten, a professor of computer science at Princeton University, and Avi Rubin, a Professor of Computer Science at Johns Hopkins University.

"The attacks described in Hursti's report would allow anyone who had physical access to a voting machine for a few minutes to install malicious software code on that machine, using simple, widely available tools," they wrote Thursday on the Freedom to Tinker blog. "The malicious code, once installed, would control all of the functions of the voting machine, including the counting of votes."

Diebold's machines are based on custom hardware that runs Microsoft's Windows CE operating system.

Black Box Voting's Harris called on Diebold to recall the machines and replace them with its optical scanners, which do not suffer from the same vulnerability. "The company sold a defective product," she said. "It should not be used in a Federal election."

Harris also called on Congress to find out why these backdoors were installed in the first place. "We need to find out how this got through the oversight system, and we need to question the programmer who did the programming under oath."