Scents and sensibility

Biometric technology isn't all about hands, eyes and faces — there's also body odor. The recent book "Biometrics: Identity Assurance in the Information Age" cites human scent among several "esoteric" biometrics. The concept involves building a sensor that can detect patterns in the chemical substances that make up a person's unique aroma. Other fringe biometric efforts focus on vein patterns, sweat pores and gait. The latter is the subject of a Defense Advanced Research Projects Agency study.

However, the book's authors caution that such esoteric examples are "not intended to suggest future directions, only possibilities." They point out that large test datasets for esoteric biometrics don't yet exist, so performance is "speculative or undetermined."

Other emerging biometrics are more down-to-earth and available for use today. Examples include voice print authentication and signature biometrics. Prianka Chopra, an industry analyst with Frost & Sullivan, sees the two methods gaining more traction in the commercial market. "I don't think government-based identification projects are where these two will get their growth," she said.

Still, Steve Chambers, chief marketing officer for voice-recognition vendor SpeechWorks International Inc., believes voice authentication can play a role at federal agencies. The State Department is evaluating the company's product in a proof-of-concept demonstration for network access control. And the Social Security Administration has run a pilot program that uses a voiceprint solution from Authentify Inc. to authenticate company representatives who file W-2s electronically.