Researchers have raised concerns over Radio Frequency Identification (RFID) security and privacy, just as US passports containing the tags are issued.

Lucas Grunwald, chief technology officer at German security consultancyDN-Systems, showed how the tags could be easily cloned, allowingduplicate documents to be produced. He demonstrated how to copy the dataonto the chips using a cheap card reader and a laptop.

However, the US Government has pressed ahead with the deployment. "TheDepartment of State is confident that the new e-passport, includingbiometrics and other improvements, will take security and travelfacilitation to a new level," the agency said in a statement.

Experts disagree. Stijn Bijnens (pictured), senior vice-president ofidentity management at Cybertrust, said: "This exploit was already awell-known fact. RFID was not originally designed for authenticatinghuman beings - more containers, packages, etc. Using RFID in this waymakes the passports less secure, not more."

He continued: "It's not just the security issue either - privacy is areal issue here, and I think we'll be hearing a lot more about this aspeople realise the implications."

The new US passports will have embedded RFID chips that broadcastpersonal details such as the name, nationality, sex, date and place ofbirth,and a digital photograph of the passport holder. US officialsclaim that a layer of metallic "anti-skimming" material on the documentwill prevent data from being read from a distance, provided that thepassport is fully closed.