Patent ID: 8868923

Claim:
A hardware device, comprising: a hardware platform; device circuitry coupled to perform a primary function of the hardware device disposed in or on the hardware platform; and a cryptographic fingerprint unit for authenticating a user of the hardware device, the cryptographic fingerprint unit including: a physically unclonable function (“PUF”) circuit disposed in or on the hardware platform, wherein the PUF circuit is a first authentication factor representing something the user has; and combining logic coupled to receive at least one other authentication factor and challenge the PUF circuit with the at least one other authentication factor, wherein the at least one other authentication factor is at least one of a second authentication factor representing something the user knows or a third authentication factor representing something the user is, and wherein the PUF circuit is coupled to receive the at least one other authentication factor as a challenge and coupled to output a PUF value in response to being challenged with the at least one other authentication factor, the combining logic coupled to generate a multi-factor authentication value based on the PUF value; wherein the cryptographic fingerprint unit uses the multi-factor authentication value to allow a challenger to authenticate the user of the hardware device.