A design for a physical RNG with robust entropy estimators

Abstract

We briefly address general aspects that reliable security evaluations of physical RNGs should consider. Then we discuss an efficient RNG design that is based on a pair of noisy diodes. The main contribution of this paper is the formulation and the analysis of the corresponding stochastic model which interestingly also fits to other RNG designs. We prove a theorem that provides tight lower bounds for the entropy per random bit, and we apply our results to a prototype of a particular physical RNG. © 2008 Springer-Verlag Berlin Heidelberg.