An electronic device, such as a payment reader, may include a physically unclonable function (PUF) source to generate a plurality of PUF values. The electronic device may also include circuitry to compare the plurality of PUF values from the PUF source to determine a degree of randomness of the at least one PUF source in generating the plurality of PUF values. The circuitry can then determine, based on the determined degree of randomness, whether to use the PUF values from the PUF source to perform a secure operation for the electronic device.