Plans for a wide-ranging review of voting machines have provoked complaints from election officials across California and delight among Southwest County activists who have criticized one variety of the machines as open to fraudulent manipulation.

Secretary of State Debra Bowen, who took over from Bruce McPherson in January, said last week that her office would examine voting machines from "top to bottom," including processes for their use. The review could lead her to bar some from use in the state, at least temporarily, she said.

The review also will include what Bowen called "red teaming" drills. In the review, a "red team" works to secure a voting system against hacking attempts by a "blue team" of rogue computer experts, Bowen said. The drills appear similar in concept to but more extensive than a public hacking attempt that Riverside County Supervisor Jeff Stone proposed for the county's touch-screen machines.

The review is scheduled to begin April 6 after Bowen finalizes a list of criteria she plans to use on the machines, according to her office. It will conclude by Aug. 3, allowing county-level elections officials six months to secure their voting systems or adopt systems that are deemed safe, Bowen said. Both major political parties in the state plan to hold their presidential nominating contests in February.

Bowen's plans sparked concerns at the California Association of Clerks and Election Officials, including worries that the six-month time frame would be short to the point of causing chaos, according to a memo the association published Monday afternoon. Numerous cities and districts in Riverside County, including Murrieta Valley Unified School District and Mt. San Jacinto College District, expect to hold elections in November of this year, Registrar of Voters Barbara Dunmore said.

Dunmore said she is optimistic that Bowen would help election officials in addressing perceived shortcomings, rather than requiring the machines to sit in storage through one or more elections. But Dunmore added that Bowen's draft criteria for the review contained few specifics. It isn't yet clear how stringent Bowen's review will be and what it will require of elections officials, Dunmore said.

"The further this goes, the tighter the time frame, the more anxious we become," Dunmore said.

A Bowen spokeswoman said her office would issue more specific criteria April 6, after hearing from local election officials, voting activists and other interested parties. In its memo, the association of election officials complained that the deadline leaves them only two weeks to comment.

As noted by Dunmore and the memo Monday, and by members of the county's governing board in the past, the county's 3,000-odd touch-screen voting machines were vetted and approved by McPherson's office early last year when they replaced a similar model. The Sequoia Edge II machines and attached printers are made by Sequoia Voting Systems, a California corporation that is based in Oakland but whose parent company traces ownership to a Venezuelan firm.

Voting-security activists have complained of that foreign ownership and of Sequoia's and other companies' refusal to open their software programming to public scrutiny, though it is kept under seal by Bowen's office. Nobody knows whether someone with access to a machine could insert a cartridge that would alter the way votes are counted, the voting activists say.

E-voting supporters counter that the touch-screen systems are secure and that even a successful hacking attempt would be rendered useless after an election, when officials compare the electronic results with paper receipts that each voting machine produces. Dunmore protested that Bowen's review appeared to focus too heavily on touch-screen machines and would not also examine flaws in other systems.

Critics have focused most heavily on the touch-screen machines used in Riverside and 20 other California counties, though a Bowen spokeswoman said the review would also include "optical scan" systems, in which voters mark their choices on paper ballots that are counted and summed by computers.

A leader of a Southwest County elections watchdog group welcomed Bowen's review, saying he expected it to address many of the group's concerns with touch-screen machines.

"This is breaking into brand new territory," said Tom Courbat, coordinator for Save R Vote, whose members have frequently criticized touch-screen machines and what they call gaps in Riverside County's procedures for using them. "No other secretary of state has tried to make the machines as bulletproof as possible.

"I don't believe that the existing machines are going to be able to pass this test," Courbat added.

Contact staff writer Chris Bagley at (951) 676-4315, Ext. 2615, or cbagley@californian.com. Comment at www.californian.com.