Two shops on the School of Mines and Technology campus are performing one of the world's first experiments in Biocryptology — 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.

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 — that deeper check to ensure the finger has a pulse — that researchers say sets this technology apart from already-existing digital fingerprint scans, which are used mostly for criminal background checks.

Al Maas, president of Nexus USA — a subsidiary of Spanish-based Hanscan Indentity Management, which patented the technology — acknowledged South Dakota might seem an unlikely locale to test it, but to him, it was a perfect fit. "I said, if it flies here in the conservative Midwest, it's going to go anywhere," Maas said.

The key to keeping biometric identification from becoming Big Brother-like is to make it voluntary and ensure that the information scanned is used exactly as promised, Stanley said.

Brian Wiles, a Miles mechanical engineering major, said it's exciting to be beta testing technology that could soon be worldwide.