A physically unclonable function (PUF) device comprises a plurality of conductors, at least some of which are arranged so that they interact electrically and/or magnetically with one another. A media surrounds at least a portion of each of the conductors and a plurality of temperature compensation particles are arranged throughout the media, where the temperature compensation particles have a temperature coefficient selected such that they compensate for temperature-related effects in the PUF device by making the permittivity and/or permeability of the media substantially temperature independent. Circuitry applies an electrical challenge signal to at least one or the conductors and receives an electrical output from at least one of the other conductors to generate an identifying response to the challenge signal that is unique to the device.