fingerprint scan

Lexington Herald-Leader (KY)

August 18, 2003

FINGERPRINT SCAN FOILS FAKE AND CUT-OFF FINGERS
DEVICE READS SKIN LAYERS, GENERATES A PATTERN

Author: Sabra Chartrand
New York Times News Service

Edition: Final
Section: Business Monday
Page: C3

Estimated printed pages: 2

Article Text:

Biometrics is the art of using unique physical characteristics like fingerprints, iris composition and voice patterns to verify a person's identity. Because those traits generally cannot be stolen, they are considered among the most secure forms of identification.

Someday, they could replace passwords, personal identification numbers, keys, photo badges and other forms of security. Of course, for all the researchers working on fingerprint protection for check cashing, automated tellers or credit cards, there is probably someone looking for a way to hijack the system.

Tricking the scanner has become a staple in movies and novels. Plots often turn on bad guys who wear latex copies of someone else's fingerprints or present a severed hand to the scanner.

With those possibilities in mind, a German inventor won a patent last week for a method of verifying that fingerprints are from "living human skin." In his patent, Stephen Marksteiner of Munich said his invention will make sure "it is not possible to obtain access authorization with fake fingers or cut-off fingers."

In his patent, Marksteiner writes that his invention is based on "the fact that living human skin has a characteristic layer structure." He says, "These layers of the skin have clearly different electric conductivities."

His invention reads signals that bounce off skin when fingers are placed on a surface embedded with electric conductors. It first applies "an AC voltage with a variable frequency to at least one electric conductor," Marksteiner writes. The system then records the frequency of electric resistance and conductivity, and the time intervals between each one. Those signals generate a pattern, which he describes as curved in shape.

"This characteristic curve shape can be faked or simulated only with difficulty when using an artificial finger," Marksteiner writes. "In the case of a cut-off finger, the curve shape changes rapidly as a result of the skin tissue dying off."

Individual readings are then compared with a template stored in the scanner system. Marksteiner says that "since only slight fluctuations are to be established between different persons, it is possible, if appropriate, also to use a single reference curve for all persons to be identified."

Marksteiner won patent 6,597,945.

A Hollywood couple once became known for each wearing a vial of the other's blood as pendants. For those wanting something similarly intimate but a little easier to explain to friends and family, a California inventor suggests "fingerprint jewelry."

Vahe Kaladjian of San Francisco won a patent for any jewelry with a person's fingerprints cast into its surface. First, a fingerprint is pressed into soft wax, which is allowed to harden. A mold is created from the wax form, and then "molten precious metal is cast into the mold cavity." The metal casting is then bent, shaped or welded into rings, earrings, pendants and the like.

The jewelry won patent 6,435,255.

Memo:
PATENTS