Even the printing of paper records — widely seen as a countermeasure to hacking and other attacks on ATM-like touchscreen machines — does little good if audits aren't routinely and automatically performed, researchers said.
While California and 11 other states require audits in addition to paper trails, more than half of the 26 states requiring paper records don't do so.
The report, based on interviews with elections officials and analyses of voting systems, came from the Task Force on Voting System Security convened by New York University's Brennan Center for Justice. Task force members were from government, universities, security companies and nonprofit advocacy groups.
For systems that spit out paper records for voters to check before leaving, the task force said audits should be routinely performed to randomly check a machine's tally against that machine's paper trail.
Otherwise, paper records do little to improve security, said Larry Norden, the task force's chairman and Brennan's associate counsel.
Researchers acknowledged that audits won't uncover attacks that change both the electronic and paper records, something possible because many voters don't bother to check the paper trail before leaving the voting booth.
Voters, researchers say, should be encouraged to check the paper.
Recommendations for all types of e-voting machines include banning wireless components, which can create openings for attack, and testing randomly selected machines on Election Day as close to actual conditions as possible to uncover malicious software and other problems triggered only that day.
"We're not talking about dramatic restructuring of the architecture," Norden said. "We're talking about straightforward things, most of which could be in place for the 2006 elections."
Ken Fields, a spokesman for e-voting manufacturer Election Systems & Software Inc., said company officials were still reviewing the report. "We certainly take all factual explanations of security issues seriously," he said.
The company also issued a statement saying that it routinely helps officials implement proper procedures for smoother elections.
The Information Technology Association of America, whose members include voting-machine vendors, denounced the study as one "based on speculation rather than an examination of the record," adding that voting systems have yet to be successfully attacked in a live election.
The machines studied by the task force — ATM-like machines and optical-scan systems that ask voters to fill in the blanks — will be used by at least four out of five registered voters this year, up from just over half the voters in 2000, according to Election Data Services, a political consulting firm that tracks election equipment.
Task force member Howard Schmidt, President Bush's former cybersecurity adviser, said no computer system can be made 100 percent risk-free, but the recommendations help by "minimizing the risk of something uncontrollable occurring and if something should occur, you would know about it."
Doug Chapin of Electionline.org, a nonpartisan research group that tracks efforts to revamp election systems, said states and counties typically have been focusing on trying to assure Americans that their vote was being recorded. Chapin, who was not involved with the Brennan study, said he expects more election officials to begin considering systematically how they can use the records more broadly, such as through audits.
According to the report, the 14 states requiring paper trails but not audits are Idaho, Maine, Michigan, Missouri, Montana, New Hampshire, New Jersey, Nevada, Ohio, Oregon, South Dakota, Utah, Vermont and Wisconsin. The 12 that require audits are Alaska, California, Colorado, Connecticut, Hawaii, Illinois, Minnesota, New Mexico, New York, North Carolina, Washington and West Virginia.
Rep. Rush Holt, D-N.J., has introduced legislation requiring paper records and random audits for federal elections in at least 2 percent of precincts in each state.