Thermal jitter (phase noise) from a free-running ring oscillator is a common, easily implementable physical randomness source in True Random Number Generators (TRNGs). We show how to evaluate entropy, autocorrelation, and bit pattern distributions of ring oscillator noise sources, even with low jitter levels or some bias. Entropy justification is required in NIST 800-90B and AIS-31 testing and for applications such as the RISC-V entropy source extension. Our numerical evaluation algorithms outperform Monte Carlo simulations in speed and accuracy. We also propose a new lower bound estimation formula for the entropy of ring oscillator sources which applies more generally than previous ones.
翻译:来自自由运行环振荡器的热振荡(相位噪音)是真实随机数生成器(TRNGs)中常见的、易于执行的物理随机性源。我们展示了如何评估环振荡器噪音源的微粒、反热和位模式分布,即使音量低或有偏差。 NIST 800-90B 和 AIS-31 测试以及RISC-V entropy源扩展等应用软件需要复选理由。我们的数字评估算法在速度和准确性上优于蒙特卡洛模拟。我们还提出了比以往更普遍应用的环振荡器源的酶的新的较低约束性估计公式。