A Hybrid True Random Number Generator using Ring Oscillator and Digital Clock Manager

Abstract

The modern cryptographic systems demand a random number generator to be of low-complexity and also be undeterminable simultaneously. The applications range from key generation, random padding bits, PIN/password generation, authentication protocols, and nonce generation. This paper introduces a new hybrid method that uses jitter as the randomness source. The proposed design incorporates a Ring Oscillators with Programmable Delay Lines and a Digital clock manager. Reduction in the correlation between the equal length ring oscillators is achieved by programmable delay lines and the Digital Clock Manager allows on-the-fly tunability which eventually enhances the randomness quality. A Von Neumann corrector is employed as a post-processor to eliminate any bias if present in the output bitstream and further improves the quality of randomness. The proposed TRNG achieves high throughput and low hardware footprint with a minimum cost of hardware. An analysis of the National Institute of Standards and Technology (NIST) tests demonstrates the effectiveness of the proposed architecture.