Asynchronous Quasi-Random Number Generator: Taking Advantage of PVT Variations

Random number generators find application in many fields, including cryptography, digital signatures and network equipment testers, to cite a few. Two main classes of such generators are usually proposed, pseudo-random number generators and true-random number generators. The former are simple to build and use, but cannot be employed in every application, especially in those where randomness is meant to support security. The later can be complicated to build, since they often must rely on hard-to-predict events that are hard to produce in the deterministic world of digital circuits. This work proposes a quasi-random number generator hardware implementation, intended to provide most of the benefits of true-random number generators with costs closer to those of pseudo-random number generators. The quasi-random number generator described here relies on the use of asynchronous circuit design techniques allied to process, voltage and temperature variability to achieve relatively high degrees of randomness. An FPGA prototype demonstrates the feasibility of the approach.