Tunnel FET-based ultra-lightweight reconfigurable TRNG and PUF design for resource-constrained internet of things

Conventional complementary metal oxide semiconductor (CMOS)-based dedicated true random number generator (TRNG) and physically unclonable function (PUF) designs have exhibited higher energy consumption and large area overhead with technology scaling. In contrast, this paper for the first time presents emerging tunnel field-effect transistor (TFET)-based ultra-lightweight reconfigurable TRNG and PUF design. A unique methodology is proposed that considers p-i-n forward current characteristics to generate random keys for PUF and TRNG designs. Leveraging the p-i-n forward current of TFET, a ring oscillator (RO) is designed that exhibits variation in the operating frequency and acts as the main source of entropy for both PUF and TRNG. The TRNG in the proposed design is robust and passed all the National Institute of Standards and Technology (NIST) tests. Considering the variation in p-i-n forward current, the uniqueness of PUF is calculated as 47.5% and 46% at a supply voltage of 0.5 and 0.45 V, respectively. Moreover, PUF achieves high reliability of 82% and 88.7% with supply voltage and temperature variations, respectively. The proposed design is proved to be compact with relatively lower gate count and shows low energy consumption of 4.8 pJ/bit at 0.5-V supply voltage. With these performance metrics, the proposed design is highly suitable for resource-constrained internet of things (IoT).