By AMBER HUNTRAPID CITY, S.D. (AP) â¿¿ Futurists have long proclaimed the coming of a cashless society, where dollar bills and plastic cards are replaced by fingerprint and retina scanners smart enough to distinguish a living, breathing account holder from an identity thief. What they probably didn't see coming was that one such technology would make its debut not in Silicon Valley or MIT but at a small state college in remote western South Dakota, 25 miles from Mount Rushmore. Two shops on the School of Mines and Technology campus are performing one of the world's first experiments in Biocryptology â¿¿ a mix of biometrics (using physical traits for identification) and cryptology (the study of encoding private information). Students at the Rapid City school can buy a bag of potato chips with a machine that non-intrusively detects their hemoglobin to make sure the transaction is legitimate. Researchers figure their technology would provide a critical safeguard against a morbid scenario sometimes found in spy movies in which a thief removes someone else's finger to fool the scanner. On a recent Friday, mechanical engineering major Bernard Keeler handed a Red Bull to a cashier in the Miner's Shack campus shop, typed his birthdate into a pay pad and swiped his finger. Within seconds, the machine had identified his print and checked that blood was pulsing beneath it, allowing him to make the buy. Afterward, Keeler proudly showed off the receipt he was sent via email on his smartphone. Fingerprint technology isn't new, nor is the general concept of using biometrics as a way to pay for goods. But it's the extra layer of protection â¿¿ that deeper check to ensure the finger has a pulse â¿¿ that researchers say sets this technology apart from already-existing digital fingerprint scans, which are used mostly for criminal background checks.