"There is a slight difference between your Pentium chip and my Pentium chip, even if they were produced next to each other in the fab," Vivek Khandelwal, Verayo's director of marketing, is quoted as saying in RFID Update. "PUFs capture the unique fingerprint of each chip by sending current through the circuit and measuring the path it takes. Verayo's technology uses the measurement data to create a 64-bit challenge that is unique to the chip," the story said. Verayo has made its case in a technical white paper on its site.
A California startup is touting technology that it argues will make RFID chips that can't be cloned. Verayo's approach is based on a circuit-building approach called PUFs (Physically Unclonable Functions), which uses subtle chip differences to fuel a challenge-and-response system.