A scalable low-entropy detector to counteract the parameter variability effects in TRBGs

In this paper we discuss a probabilistic feedback technique to maximize the throughput of a generic True Random Bit Generator (TRBG) circuit, under a given constraint on the entropy. In the proposed approach, the throughput of the device is dynamically and adaptively varied by an on-line entropy detector, such to obtain, with an arbitrary confidence level, an entropy greater than a given worst-case value. The method can be applied to all the integrated TRBG circuits proposed in the literature that are based on the uniform sampling of, e.g., random physical processes or chaotic dynamical systems.