At 12:07 PM 9/20/02 -0400, Perry E. Metzger wrote: > >A couple of places have reported on this: > >http://www.nature.com/nsu/020916/020916-15.html > >An idea from some folks at MIT apparently where a physical token >consisting of a bunch of spheres embedded in epoxy is used as an >access device by shining a laser through it. > >On the surface, this seems as silly as biometric authentication -- you >can simply forge what the sensor is expecting even if you can't forge >the token. Does anyone know any details about it?
This kind of thing has been done as "conformal coatings" in nuke-tracking work. Also diamond-tracking. The idea is you have a complex, optically-coupled-state (metal flakes or spheres in clear paint/epoxy; crystal flaws) which you can read out but not duplicate. This kind of 'unduplicable' conformal coating may appear on US-bound Canadian trucks, too. Certify in the great white north, spray, measure, drive, re-measure, pass, look ma, no long lines at the border. --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]