Patent ID: 11734459

Abstract:
Physical Unclonable Functions, PUFs, are hardware devices designed to generate a number that is random (i.e., two identical PUFs should produce randomly different numbers from each other) and persistent (i.e., a PUF should consistently generate the same number over time). Over time, aspects of the PUF hardware may change or drift, which may ultimately cause the generated number to change, and therefore no longer be persistent. Failure to generate a persistent number may cause difficulties for other devices that rely on the persistence of the number generated by the PUF, for example as part of a cryptographic process. The present disclosure relates to monitoring over time the physical characteristics of the PUF that are used to generate its number, and thereby keep track of its reliability to generate a random number that is persistent. By monitoring PUFs in this way, it may be possible to detect in advance a PUF that is at risk of generating a number that is no longer persistent, so that pre-emptive action may be taken before the PUF actually fails.