Electronic passports being introduced in the US and other countries have a major vulnerability that could allow criminals to clone embedded secret code and enter countries illegally, an expert said.
A demonstration late on Friday by German computer security expert Lukas Grunwald showed how personal information stored on the documents could be copied and transferred to another device.
It appeared to contradict assurances by officials in government and private industry that the electronic information stored in passports could not be duplicated.
"If there is an automatic inspection system, I can use this card to enter any country," Grunwald said, holding up a computer chip containing electronic information he had copied from his German passport.
The research is the latest to raise concerns about the growing use of radio-frequency identification (RFID), which allows everyday objects such as store merchandise, livestock and security documents to beam electronic data to computers equipped with special antennas.
Countries such as Germany already use RFID in passports to help border officials guard against forgeries and automate the processing of international visitors. US officials plan to start embedding RFID in passports in October.
The presentation was one of dozens delivered at the Defcon conference held through yesterday in Las Vegas. The conference, attended by many of the world's best-known security experts, has become an annual showcase of the latest discovered weaknesses in computers, phone equipment and other machines.
Another security professional, Arias Hung, a security professional with Media Access Guard in Seattle, showed how people can have their phone numbers hijacked when using certain types of equipment that route calls over the Internet.