A Novel Pentagonal Ring Oscillator as a True Random Number Generator

This paper introduces a novel Pentagonal Ring Oscillator (PRO) for True Random Number Generators (TRNGs) that leverages both metastability and jitter to generate high-quality random bits. Compared to standard hexagonal and tetrahedral ring oscillators, the proposed pentagonal design reduces the number of inverters by 41.7 % relative to the classical hexagonal topology. The PRO circuit is validated through Cadence Virtuoso simulations using North Carolina State University's 45 nm technology. Synopsys Design compiler is used showing that the PRO is superior in area, power, maximum frequency and energy per bit, relative to the tetrahedral and hexagonal ring oscillators. Experimental implementation confirms these findings, and the randomness of the generated bits is verified using the National Institute of Standards and Technology (NIST) test suite.