US Patent 11652649 Sensor secured by physical unclonable function (PUF)

Any electrical component that is responsive to a physical or environmental phenomenon may be used to create a secure sensor. A secure sensor may include a first electrical component having a first side connected to a voltage source, a second component having a first side connected to the voltage source, an analog comparator having a first input connected to a second side of the first component and a second input connected to a second side of the second component and an output that represents at least one bit of a key, and an analog to digital converter having an input connected to the second side of the first component wherein an output of said analog to digital converter is related to a physical phenomenon that the component responds to by a coefficient of the components characteristic. The first component and the second component may have the same nominal value. The first component, the second component and the analog to digital comparator may be encased in the same package. The package may be configured to inhibit inspection and discovery of components contained in said package. A processor may be connected to a key register and to a table containing the information related to the sensed physical phenomenon wherein the processor may be configured to store the key bits in the key register and is configured to store data corresponding to the sensed physical phenomenon. The processor may be configured to store a time stamp associated with an entry in the table. A communications interface may be connected to the processor.