A Novel Low-Power True Random Number Generator Using LOMOS Topology with Entropy-Based Adaptive Windowing

An important module that must be present in any communication system is a random number generator (RNG). One of the RNGs is the True RNG (TRNG), which is completely random. The output of the TRNG is unpredictable as it extracts its randomness from physical phenomena such as temperature, noise, power supply fluctuations, timing jitter in oscillators, and metastability in digital circuits. It is used in many applications such as cryptography, IoT sensors, and mobile equipment. In this paper, a novel low-power TRNG architecture is proposed: its core novelty is that all the system modules are adaptive to be more efficient and cooperate with system variations. It consists of a morphing gated ring oscillator, a lightweight real-time entropy monitoring, and a dynamic sampling window. Each module is verified before system integration. Our system strikes a favorable trade-off between randomness and power consumption as all the modules are implemented using LOMOS standard cells—a power-efficient topology for CMOS logic gate design. It consumes 0.226 μW from a 0.4 V supply at 1 MHz. The proposed architecture is evaluated using the NIST SP 800-22 statistical test suite, and successfully passes 10 randomness tests.