"We have grave reservations about the safeguards in place with many of the computerized voting technologies being used," Eugene Spafford, chairman of the Association for Computing Machinery's Committee on Public Policy.

"New federal standards and a certification process hold promise for addressing some of these problems, but more must be done to ensure the integrity of our elections in the face of software and hardware errors as well as the possibility of undetectable tampering," Spafford told a joint House hearing.

David Wagner, an associate professor at the University of California at Berkeley and a specialist in information security and electronic voting, went further. "We've seen security defects that allow a single person with insider access and some technical knowledge could switch votes, perhaps undetected, and potentially swing an election," he testified. "These problems should be weeded out by the independent testing process, but it is clear that this system isn't working."

The House hearing considered whether voluntary U.S. standards for voting equipment issued in 2005 are sufficient to improve voting machine security. A recent Government Accounting Office report found inconsistent application of the federal specs.

Spafford also released a list of steps to ensure accurate and secure voting. They include: