A 2.4-Gb/s, 1.9-fJ/bit Nested Chaotic Oscillator-Based True Random Number Generator With 4–398-K Operation

A 2.4-Gb/s and 1.9-fJ/bit true random number generator (TRNG) featuring a novel entropy source is presented. The proposed nested chaotic oscillator (NCO) leverages the chaotic behavior of cascaded nested sinusoidal functions to enhance energy efficiency and ensure sufficient entropy across various process, voltage, and temperature (PVT) corners. The proposed TRNG has been tested under a supply attack of up to 1.4 Vpp, operating across a supply voltage range of 0.4–1.4 V, and a temperature range from 4 to 398 K, while successfully passing the NIST 800-22 and 90 B randomness tests. Fabricated in a 28-nm CMOS process, the prototype achieves a throughput of 2.4-Gb/s with a power efficiency of 1.9-fJ/bit at a 0.4-V supply.