  Physical unclonable function (PUF) has been proposed as a promising and
trustworthy solution to a variety of cryptographic applications. Here we
propose a non-imaging based authentication scheme for optical PUFs materialized
by random scattering media, in which the characteristic fingerprints of optical
PUFs are extracted from stochastical fluctuations of the scattered light
intensity with respect to laser challenges which are detected by a single-pixel
detector. The randomness, uniqueness, unpredictability, and robustness of the
extracted fingerprints are validated to be qualified for real authentication
applications. By increasing the key length and improving the signal to noise
ratio, the false accept rate of a fake PUF can be dramatically lowered to the
order of 10^-28. In comparison to the conventional laser-speckle-imaging based
authentication with unique identity information obtained from textures of laser
speckle patterns, this non-imaging scheme can be implemented at small speckle
size bellowing the Nyquist--Shannon sampling criterion of the commonly used CCD
or CMOS cameras, offering benefits in system miniaturization and immunity
against reverse engineering attacks simultaneously.
