Imperfect Silicon, Near-Perfect Security
Some chipmakers, under pressure to add security to rapidly growing numbers of IoT devices, have rediscovered a “fingerprinting” technique used primarily as an anti-counterfeiting measure.
Physically unclonable functions (PUFs) are used to assign a unique identification number based on inconsistencies in the speed with which current causes a series of logic gates to open or close. So otherwise identical chips will deliver different results in identical test circuits due to random variation in the speed with which those gates respond to a test, according to a 2007 paper by MIT researcher Srini Devadas, who discovered the pattern and founded the company Verayo to commercialize systems that use it. More