A federal online voting system for U.S. military personnel and other citizens overseas is so fraught with security risks that it should be shut down before it is put in place next month, according to four researchers asked to analyze it.

Since the system relies on the Internet and personal computers, voter privacy could be jeopardized and votes could be altered by hackers or even terrorists, and it could change the outcome of a close race, the report released Wednesday concludes.

“Computers were not built to be voting booths,” said Avi Rubin, associate professor of computer science at Johns Hopkins University and one of the report’s authors. “They’re vulnerable to all kinds of attacks and viruses.”

The new Internet-based voting system, being administered by the U.S. Department of Defense, is called the Secure Electronic Registration and Voting Experiment, or SERVE. Up to 100,000 voters who hail from seven states are expected to use it to cast ballots in this year’s primary and general elections.

SERVE’s rollout is expected to be in place in time for the South Carolina primary Feb. 3. Despite the criticisms, there are no plans to slow down the process.

“We respect what they have done. They have excellent credentials,” said Glenn Flood, a Defense spokesman. But, he said, “we plan to continue the program.”