Bruce McPherson, the Republican incumbent, has said the state has the most rigorous standards in the country for voting machines and that the system is safe.

But Bowen said the software that runs the machines - and the tally cards that slide in and out of the machines - can be tampered with to alter results.

"We know of no software in the history of computers that doesn't have bugs in it," she said at the luncheon meeting of Women in Leadership at the Westin South Coast Plaza. "You can hack into any computer. ... We do a much better job of auditing slot machines than we do voting machines."

She would like to see the secret, proprietary "source code" of the machines made public to allow better monitoring of the software. And once an individual voting machine has failed, she would like to see it removed from service until it can be checked out - not simply repaired on Election Day and put back in service.

Bowen, of Marina del Rey, faces an uphill battle in challenging an incumbent, although she has been building credentials for the job.

As chairwoman of the Senate elections committee, she has been active in voting issues and last year sponsored a successful bill requiring an audit of 1 percent of the electronic vote, comparing the electronic tally to the parallel paper totals to ensure they match.

She would like to also see 1 percent of absentee ballots audited.

McPherson, a former state legislator appointed to the state's top elections job in March 2005, developed a 10-point requirement for certification of voting machines.