Spooked by reports that new, sophisticated voting machines may be vulnerable to tampering, North Dakota election officials have changed plans to install them within three years.

A state blueprint for complying with a new federal voting access law no longer includes references to county use of "touch screen" machines for casting ballots.

The machines, called DREs - short for "direct recording electronic" - allow voters to make their ballot choices without marking a piece of paper. Votes are recorded electronically when a voter touches a screen, or pushes a button.

DRE systems are already used in a handful of states, including California, Georgia and Kansas. Maryland recently signed a contract to put machines in each of its voting precincts by March 2004.

North Dakota's plan for complying with the federal law has included equipping each polling place with at least one electronic voting machine in time for the 2006 elections.

But a committee of election officials and interested observers, which is drafting state plans to meet the federal law's requirements, agreed last week to eliminate its references to voting machines.

The change will give officials more leeway to monitor the machines' development, and more time to pick the best solution, said Cory Fong, North Dakota's deputy secretary of state.

"It does provide us with a pause before moving forward with any kind of specific technology," Fong said.

The decision was in response to a report published last month by computer security experts at Johns Hopkins University in Baltimore.

They examined the computer code used in a DRE made by Diebold Election Systems, a unit of Diebold Inc. of North Canton, Ohio. Diebold is one of the nation's largest makers of cash-dispensing automatic bank teller machines.

The study concluded that Diebold's machine could be easily manipulated by someone with little computer savvy.

"Common voters, without any insider privileges, can cast unlimited votes without being detected by any mechanisms within the voting terminal," it said. "As a society, we must carefully consider the risks inherent in electronic voting, as it places our very democracy at risk."

Diebold said the Johns Hopkins report was flawed, and ignored safeguards that election officials already have in place to detect and combat vote tampering.

Under the North Dakota plan, DRE machines would be available at each precinct as a way to allow people with disabilities to vote without any assistance. However, the machines' use would not be reserved only for the disabled.

County election officials say that optically scanned ballots, which are filled in with a pencil and read by a machine, are likely to be the primary way of voting statewide.

Cass County already uses optical readers that can detect voting mistakes, such as voting for too many candidates for county commissioner or the state Legislature, along with providing a quick vote tally.

"That's the nice thing about having a physical ballot. You can count them," said Mike Montplaisir, the Cass County auditor. "People have problems with DREs because they can't see anything."

Some computer experts and election observers say the touch-screen machines should also print a paper slip, which the voter would then check. The slip would then be kept for auditing purposes, or in case a re-count was necessary.

"Paperless DRE systems tell voters to just trust us that the system will work," said Stanford professor David Dill, a critic of touch-screen machines. "That diminishes voter confidence."

Fong said state and county officials will be looking at their technology options. "There's going to be a lot more information about this, and we're going to monitor it very closely," he said.

Montplaisir said he would prefer a paper record of votes cast on touch-screen machines.

"I think the DREs are very reliable, but people have to be able to trust the system," he said. "If you're not comfortable with the electronics, you're not going to be able to trust them."