4 Physical Random-Number Generators

Abstract

The doctrine in cryptology is that the algorithm of encryption is known to the adversary (Eve) and that the only thing that is kept secret is the key, which normally is a bitsequence or a sequence of natural numbers or elements of a finite ring (e.g. a residue ring or a finite field). Mostly, such key sequences are produced by an algorithmic generator (i.e., they are socalled pseudo-random numbers), since these offer the following benefits: the sequence of numbers can be reproduced for debugging and testing; no special hardware is necessary; a large quantity of random numbers can be produced in a short time.