True Random Number Generators Secure in a Changing Environment: Improved Security Bounds

Barak, Shaltiel Tromer showed how to construct a True Random Number Generator (TRNG) which is secure against an adversary who has some limited control over the environment. In this paper we improve the security analysis of this TRNG. Essentially, we significantly reduce the entropy loss and running time needed to obtain a required level of security and robustness. Our approach is based on replacing the combination of union bounds and tail inequalities for `-wise independent random variables in the original proof, by a more refined of the deviation of the probability that a randomly chosen item is hashed into a particular location.