Multi-PUF authentication from sensors and their calibration

Several methods may be used to exploit the natural physical variations of sensors, to generate cryptographic physically unclonable functions (PUF) that may strengthen the cybersecurity of microelectronic systems. One method comprises extracting a stream of bits from the calibration table of each sensor to generate reference patterns, called PUF challenges, which can be stored in secure servers. The authentication of the sensor is positive when the data streams that are generated on demand, called PUF responses, match the challenges. To prevent a malicious party from generating responses, instructions may be added as part of the PUF challenges to define which parts of the calibration tables are to be used for response generation. Another method is based on differential sensors, one of them having the calibration module disconnected. The response to a physical or chemical signal of such a sensor may then be used to authenticate a specific pair of sensors.