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Disabling the RFID in the New U.S. Passports

Posted by Zonk on from the very-high-tech dept.

slashchuck writes "Along with the usual Jargonwatch and Wired/Tired articles, the January issue of Wired offers a drastic method for taking care of that RFID chip in your passport. They say it's legal ... if a bit blunt. From the article: 'The best approach? Hammer time. Hitting the chip with a blunt, hard object should disable it. A nonworking RFID doesn't invalidate the passport, so you can still use it.' "

1 of 294 comments (clear)

  1. Re:Somebody doesn't grok RFID... by canavan · · Score: 5, Interesting
    passive (powered by the magnetic field generated by an RFID reader).
    Passive RFID tags are not powered by magnetic, but by electromagnetic fields, more precisely essentially the same radio frequency they use to send back their data - they use the same antenna for sending and receiving.

    someone with even a basic knowledge of physics knows that the power requirement to maintain an adequate magnetic field increases exponentially with distance.
    Since we determined that radio is used to power the tags, everyone with a basic understanding of physics should know that the field strength diminishes with something like x^-3 and not y^-x, which would make it a cube law matter, and not exponential. Additionally, the same directional antenna that can be used to read the tag's signal can be used to direct the radiated RF energy to the tag.

    one has to remember that tags operating on the same frequency will tend to interfere with each other, reducing the chance of getting a good read.
    Sorry, but that's wrong again. RFID tags only send an answer when they are specifically addressed. The inventory control tags allow for a binay search to find all tags, e.g. you start by asking if any tag have addresses <2^31. If any answer, you check < 2^30 and between 2^31 and 2^30, etc. until you know the individual addresses of all tags in your range. Only after you have the right adress you will start actually reading their data, anything before that is just to detect their presence. Whether or not passport tags even give away their presence if one doesn't provide the (printed) secret key in the request, I do not know.