Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Saw a novel use for PCBs yesterday on Mythbusters.

They had to get past a fingerprint lock.

The way they did it was lift a fingerprint, scan it, touch it up, etch
a PCB from the image, and then cast latex or gelatine over it to make
a 3D finger.

It worked! The simple PC lock was fooled by it, when it did not take a
simple printout on paper. The supposedly advanced door lock was even
fooled by the paper print, once it was licked to simulate the
conductivity.

Shows how simple these locks are to fool. I mean, come on, using a key
that leaves an exact print of it's shape hundreds of times a day for
anyone to pick up, just crazy!

Anyway, really interesting use of a PCB to make a precise
two-and-a-half dimensional mold of the fingerprint. They used
photoprocess by the way, and FeCl.

ST