The idea is not as rank as it may seem. Dogs are said, at least by dog handlers, to recognize the scents of individual people. Researchers have found that mice can detect from body odor and urine how closely they are related to one another, a useful way to avoid inbreeding. So Darpa, the grand patron of exotic military arts (not everything it does works, but it did have a hand in creating the precursor of the Internet), is soliciting "innovative proposals to (1) determine whether genetically-determined odortypes can be used to identify specific individuals, and if so (2) to develop the science and enabling technology for detecting and identifying specific individuals by such odortypes."
With the high-tech identification industry going into full gear with machines that recognize fingerprints and scan the iris, why is Darpa messing with something as old-fashioned as B.O.? Dr. Gary Beauchamp, director of the Monell Chemical Sense Center in Philadelphia, notes that odors can be detected through just a handful of molecules. Also, unlike sight and sound, the smells from a fugitive can linger for hours or days.
Nicholas Wade, "On the Scent of Terrorists," The New York Times, January 5, 2003
—K. Yamazaki et al., “Discrimination of odortypes determined by the major histocompatibility complex among outbred mice,” Proceedings of the National Academy of Sciences, April 26, 1994