No single network security technology arouses passionate debate like biometrics, which relies on authenticating identities by matching a person's body parts, voice or signature to grant access to computer resources or restricted building areas.No single network security technology arouses passionate debate like\u00a0 biometrics, which relies on authenticating identities by matching a person's body parts, voice or signature to grant access to computer resources or restricted building areas.Proponents say authentication based on aspects of an individual's body - such as fingerprint matching or iris scanning - offers far better security than any based on re-usable passwords or hardware tokens that generate one-time passwords. "We've been doing large-scale ID systems for 12 years for [the Department of Defense] and the Department of State, and biometrics is a very compelling technology," says Tim Corcoran, senior systems engineer at Northrup Grumman's IT division."Biometrics is not ready for prime time," says Stephen Elky, security auditor at Software Performance Systems in Arlington, Va., which tested biometrics products under government contract.But critics point out that biometrics can be expensive and invasive, and that none of the hundreds of biometric products on the market is infallible in pattern-matching a scanned body part to a biometric image. "It's all snake oil," scoffs Jim Kirby, network engineer at Wells-Dairy, pointing to a widely publicized experiment in Japan earlier this year that showed people could fool fingerprint scanners by using molded "gummy fingers"\u00a0made of gelatin.Biometrics believersDespite the back and forth, biometrics continues to work its way into more environments.A case in point is the U.S. government, which is poised to deploy biometrics on an unprecedented scale for improving security in the military, transportation industry and in border-crossing control. That could really give a boost to a market that has increased steadily, if not spectacularly - IDC analyst Charles Kolodgy says the market increased from $77 million in 2000 to $80 million last year and is expected to grow 15% to $92 million this year.Northrop Grumman, which has worked with the U.S. Air Force and other parts of the Defense Department to install iris and fingerprint scanners, expects to see the U.S. government install hundreds of thousands or even millions of biometric products in years to come. The rollouts will be fueled in large part by mandates from Congress through the U.S. Patriot Act and the Bush administration through its homeland security efforts.The State Department, the U.S. Customs Service and the Immigration and Naturalization Service all are being asked to collect fingerprints of foreign visitors and transportation workers, among others, to authenticate identities through the use of biometrics. These new systems will need to work with the FBI's Automated Fingerprint Identification System, Corcoran says.Another user is the University of Missouri's School of Dentistry, which a year ago installed the\u00a0 SecuGen\u00a0fingerprint scanner in 265 dental laboratory settings."Missouri law requires a signature from a practitioner to practice on a patient," says biomedical communications director Bill Marse. The dentistry school had moved to a system based on electronic records as part of a Year 2000 upgrade, and the school was interested in using biometrics for access to these electronic patient records and for a signature.Student and faculty are now required to share a thumbprint, which is stored as a mathematical "hash" in a server on the university's Ethernet LAN so that it can be checked every time a student or faculty member accesses a patient's record. The fingerprint reader is built directly into the computer mouse.Fingerprint scanning won out over retinal scanning, in part because at $200 per device it cost two to five times less, Marse says.Biometrics holds a lot of appeal to hospitals seeking to carefully follow the federal government's Health Insurance Portability and Accountability Act regulations, which require authenticating user access to records.Rich Rauscher, manager of technology architecture at Moffitt Cancer Center in Tampa, Fla., this year started using\u00a0 BioNetrix Systems' authentication management software to support fingerprint readers on about 1,000 desktops, providing nurses and other staff with access to clinical records.Rauscher says he likes that BioNetrix also supports cornea scanners, face recognition and voice recognition, in addition to password-based authentication, in the event the hospital decides to make use of those technologies.Not perfectEven biometrics backers acknowledge the technology isn't perfect."We've had a few glitches," the University of Missouri's Marse says. "If part of the system isn't up, it creates a problem of phenomenal scale for us." When that occurs, the university shifts to paper backup.But in general, the biometrics-based system has worked well and the university plans to expand use to include hand-held tablets, Marse says.Another hospital, also using BioNetrix software, found fingerprint scanners to be ineffective for surgeons. They scrub their hands so thoroughly it makes it hard to read their fingerprints, says Gene Gretzer, a senior analyst at St. Luke's Episcopal Health System in Houston.WorldCom steered clear of fingerprint scanning because fingerprints are so closely associated with criminal suspect bookings at police stations that employees and customers would see such scanning as invasive, says Tim Burke, manager of infrastructure services. Rather, WorldCom uses hand scanners to ensure only authorized parties access its 14 data centers.Security experts generally prefer fingerprint biometrics to face, eye or hand geometry, to get a pattern match. Facial recognition has only about an 85% success rate for matching, while fingerprints range close to 99% accuracy, says Richard Langley, an expert in identity technologies in TRW's public safety and transportation division.Although a biometric fingerprint is unique, no person actually presses his finger the exact way twice onto a scanner. So software has to be designed carefully to prevent false rejections and false positives. That means biometrics often remains a highly customized application. It's often used in conjunction with passwords and smart cards as a back-up or double-check system.The scalability of biometrics systems also is questioned. Even a supporter such as Northrop Grumman's Corcoran says "the reality is that performance is an issue" in large-scale rollouts.James Wyman, director of the biometrics test lab at San Jose State University, which started doing testing back in the early days of the Clinton administration, adds: "A lot more research needs to be done on that." Body by biometrics Many different body parts are exploited by makers of biometrics tools for securing access to networks. Iris: The colored ring of textured tissue that surrounds the pupil of the eye has a unique structure. Retina: The layer of blood vessels in the back of the eye has a unique pattern. Face: Facial images, or a collection of images, are captured by a video camera. Fingerscanning: Minutiae of the finger image is captured via techniques known as optical, thermal or tactile. Hand geometry: A 3D image of the hand measures the shape and length of fingers and knuckles. Signature: Looks at the way we sign our names rather than the finished signature. Voice: Measure the sound of the voice; useful in telephone-based applications.