BitFlow equipped sensor system goes beyond skin level to discriminate between real and fake fingerprints
Woburn, MA, December 9 - Simple fingerprint casts made from material such as Play-doh®, clay or gelatin can fool most fingerprint recognition devices. In fact, a recent study funded by the Department of Homeland Security found that wearing fake prints, known as "spoofing" in law enforcement circles, can beat a standard fingerprint scanner 80 percent of the time. This is bad news for forensic experts confronted by criminals who will employ whatever means possible to thwart security and identification systems.
The problem is obvious: traditional fingerprint scanning devices use basic technology, such as an optical camera that takes pictures of only the very top layer of skin. Along with being tricked by spoofing, these devices sometimes fail to recognize legitimate prints when the finger being scanned is dirty, worn, scarred, or too wet or dry.
Now scientists from The Langevin Institute, Paris, France, have developed a new fingerprint imaging system that peers inside the finger to identify an individual quickly and accurately. Egidijus Auksorius, postdoctoral researcher at The Langevin Institute, and Claude Boccara, a professor who specializes in scientific instruments, engineered a machine that captures "internal fingerprints" which have the same topographical features as external fingerprints, but are about half a millimeter below the skin's surface. The system can also image sweat pores, which provide an additional means of identification.
BitFlow, Inc., a worldwide innovator in machine vision technology, is playing a crucial role in the system's design. Its new Cyton CXP4 CoaXPress frame grabber allows the interface of an Adimec® two-megapixel CXP-6 camera with the system's host computer, without requiring external power supplies or extra cables to uplink communications. By using the Cyton CXP4 frame grabber, video can be captured at speeds of up to 6.25 Gigabits/Second (Gb/S). Simultaneously, control commands and triggers can be sent to the camera 20 Mb/S. Up to 13 W of power can also supplied to the camera. Impressively, all this happens over a single piece of industry standard 75 Ohm coaxial cable.
The internal fingerprint sensor is based on full-field optical coherence tomography (FF-OCT) that Boccara's laboratory invented and developed back in the early 2000s. Unlike standard OCT, which gathers 3D data and requires high-tech lasers, FF-OCT can use spatially and temporally incoherent source and is based on 2D detector so it is faster, less expensive and easier to deploy when it comes to recording en face images, such as fingerprints. FF-OCT works by analyzing the interference patterns created when a beam of light coming from the predetermined depth of a biological sample, such as a finger, is recombined with a reference beam of light.
Images of an internal fingerprint can be captured in under a second, which is adequate for live fingerprint imaging applications. Speed is important because any finger movement will compromise the quality of the image. With its four links, the Cyton CXP4 helps to minimize acquisition time when configured for CoaXPress Quad version (4 x CXP-6) so that Adimec's CXP-6 camera can operate at a total data rate of 25 Gb/S.
In a scientific paper published in a leading journal, Auksorius and Boccara initially utilized an expensive InGaAs camera but recently have demonstrated that images of the internal fingerprints of similar quality can be recorded by using a new silicon camera from Adimec, thanks to the camera's high frame rate and pixel's high full well capacity. A compact LED source emitting at 780 nm is used to provide illumination.
"The performance of the BitFlow Cyton CXP4 enabled us to capture images at the camera's full speed, giving us a distinct competitive advantage on the innovation curve," Auksorius said. "It provides the ideal interface for running a CoaXPress-based camera system to support real-time visualization."