These measures have at least partly mollified some critics, including Ari Juels, chief scientist and director of RSA Laboratories in Bedford, Mass., who analyzed earlier versions of the embedded-chip passport and found them wanting.
"At the moment, the security protections in U.S. passports are pretty good," Juels said.
But Juels said RFID technology is potentially vulnerable. And other experts say they found flaws. The unconvinced critics include Mahaffey, a co-founder of Flexilis Inc., a mobile security company that made the video of the exploding trash can.
If your passport book falls open by even half an inch, Mahaffey said, a nearby person could wirelessly detect that you are an American and, conceivably, trigger a bomb as you pass by -- although the likelihood of the latter is "very low," he conceded. (The State Department disputed the validity of his video.)
Another expert, Lukas Grunwald, chief technology officer with the German security company DN-Systems Enterprise Internet Solutions, says he was able to copy data from an RFID chip on a German passport and transfer it onto another passport.
Although the digital signature on U.S. chips could detect such fraud, Grunwald said his demonstration suggested that criminals might be able to use the chips to introduce malicious viruses into the inspection system.
In the end, given the new technology and its complexity, it's impossible to know whether the RFID chip is 100 percent safe, experts said.
"We know that there are counterfeiters out there," said Michael Holly, chief of the international-affairs staff in the passport-services directorate of the State Department. "I don't think anyone will say ... the document is foolproof."
Jane Engle writes for the Los Angeles Times.
