The Department of Homeland Security is experimenting with radio-frequency identification technology to track foreigners as they enter and leave the country. The agency hopes the technology will improve border management without delaying travelers.

RFID tags will be tested at a simulated port this spring, then at border crossings in Arizona, New York, and Washington state from July through spring 2006. "Through the use of radio-frequency technology, we see the potential to not only improve the security of our country, but also to make the most important infrastructure enhancements to the U.S. land borders in more than 50 years," said Asa Hutchinson, Homeland Security's undersecretary for border and transportation security, in a statement last week.

The tests will help determine whether to affix RFID tags to passports, visas, or other documents visitors must carry during their stay in the United States. The tags shouldn't slow visitors' movements through border crossings, a Homeland Security spokeswoman says. For tracking foreign visitors, RFID is more efficient than current rubber-stamping technology, Meta Group analyst Gene Alvarez says.

To protect privacy, the tags won't hold visitors' personal information, only serial codes linked to information stored in the Homeland Security Department's US-Visit (U.S. Visitor and Immigrant Status Indicator Technology) databases. The codes would be meaningless to any third party trying to access the information.

The tags will be tamperproof and difficult to counterfeit. Information on them can't be changed, and they won't be activated until they're issued. All this will prevent "skimming," the use of unauthorized reading devices to capture information from RFID tags, the government says. The tags also can't be used to track visitors' whereabouts while they're in the United States.