Your Fingerprint Buys Groceries in Seattle

lildogie writes: "The Seattle Post-Intelligencer reports that a Thriftway grocery store is installing fingerprint scanners that they will use to identify customers." Each customer's payment method (credit, debit) is then automatically applied at checkout. Haven't they seen Charlie's Angels?

Comments

Re:Low tech implementation

[irony nazi]

I'm sorry to debunk you Ms. Angela of LANL, but your statement is nonsense.

I design software for biometric systems and although I don't know where they are installed at, the US Gov. is our largest client. *NO* current systems verify a third dimensional component. The neural network that IDs the print is fed many parameters. Amongst them is color (as you stated), thumbprint temperature,ambient and outdoor temperature (because the human extremity body-temperature is so dependent upon the environment), plus many more features from the actual 2-Dimensional image. There is no 3-D component.

You might argue that the angling of the scanning lasers adds a third dimensional component (a shadow) to the 2D image, but this is still something that could be duplicated given an image.

A very basic components analysis of the Neural Network will show that the thumb temperature is an ineffective means of classifieing the print, yet where I work, marketing insists that we continue to use this. That is why we have tried to increase the temperature importance by also including ambient temperatures, but mostly, the temperature is useless as a classification feature.

As far as taping a photocopy of somebody's fingerprint to the scanner this won;t work. Our scanners are color images, and the light from the photocopier has to come in at the same angle as the lasers. Using a pane of glass, a red light angled in the right direction, and a camera, we have been able to create photos that pass for fingerprints ~97% of the time. The percentage would be slightly increased if you kept the image in your pocket (body-heat) until placing it on the thumbprint scanner. This number approaches the number of false-negatives that you get with any thumbscanner.

Using biometric information creates a *real* problem for identity theft. Bruce Schneier points this out in his second book. If the advanced criminals can't reproduce your thumbprint, then they might as well intercept your biometric going from the scanner to the computer and reproduce that on all subsequent machines.

This is something that I will definitely opt out of in the future. Using a pseudo-random key generator on a cel-phone and having it transmit the key would be more accurate than a biometric.