Security at Your Fingertips.

long entertained James Bond fantasies. While walking to work in midtown Manhattan, I often imagine myself as an agent for the British intelligence service, hunting down Dr. No or Goldfinger or Blofeld as the silhouettes of beautiful women dance languidly in the background. I drink vodka martinis (shaken, not stirred), and I would certainly drive an Aston Martin if I could afford one. I recently got a chance to act out my spy dreams after I learned about a new class of fingerprint security systems that can work with your PC or laptop. These relatively inexpensive devices can protect your own top-secret electronic files by recording your fingerprint—any finger or thumb will do—on a small sensor attached by a USB line to your computer. Thereafter anyone seeking to open the files must place a finger on the sensor; if the print does not match the recorded data, access is denied. Fingerprint au-thentication can also provide an extra level of security when you're conducting transactions on the Internet. And the technology can stop hackers from breaking into corporate or government networks , because it's a lot harder to steal a finger than a password. For years, researchers have been tinkering with identification systems that could recognize a user's voice, face, handwriting, or patterns in the iris and retina. (The field is known as biometrics.) Fingerprint identification is the simplest method because every print has a unique set of clearly defined markers: the coordinates of the minutiae points, the places where the epidermal ridges begin and end. These points are what the police use to match the fingerprints left at a crime scene with those of a suspect [see " No Two Alike, " In some ways, though, a fingerprint-verification device for PC users must be more fault-tolerant than the systems devised for law-enforcement agencies. Police officers can make sure they get readable prints by carefully rolling a suspect's fingers on a traditional ink card or an electronic scanner. In contrast, most PC users won't be so meticulous; a commercial system must be able to verify their prints even if their fingers are positioned sloppily or speckled with glazed sugar. The security system developed by DigitalPersona, a firm based in Redwood City, Calif., is designed to recognize even the muddiest fingerprints. The compa-ny's U.are.U 4000 sensor is smaller than a deck of cards and has an oval plastic window on which you …