The decision to cancel the computer voting project was made by Deputy Defense Secretary Paul Wolfowitz.

Pentagon officials say he ordered the system scrapped because of an inability to ensure the legitimacy of the votes that would be cast.

The congressionally-mandated ballot project was called SERVE, which stands for Secure Electronic Registration and Voting Experiment.

In the 2004 election year, it was to have been tested by an estimated 100,000 absentee voters, most of them military personnel, registered to cast ballots in several U.S. states. A Pentagon spokesman, Glenn Flood, said last month the system could be used during some of this year's late primary contests and would definitely be used in the November election.

But four computer security experts said last month in an independent report that the system should be scrapped because it was, in their view, too vulnerable to computer attack.

They said weaknesses in the system could jeopardize voter privacy and allow votes to be altered and even election results to be tampered with. They said there were far too many opportunities for hackers or even terrorists to interfere with fair and accurate voting.

At the time the Pentagon brushed aside the warning. Spokesman Glenn Flood acknowledged there was no such thing as 100 percent security on the Internet. But he said the experts' bottom line, to be safe, don't do it,- was unacceptable. He also said the experts' concerns were well-known and predicted they would be resolved.

Despite the Pentagon's change of mind, officials say the Defense Department will still look into the technical aspects of casting ballots by the Internet in hopes another, more suitable system can be devised.

A small-scale test of computer voting was conducted in the 2000 election by a small number of mainly military personnel registered to vote in four states.