SI PUF: An SRAM and Inverter-Based PUF With a Bit Error Rate of 0.0053% and 0.073/0.042 pJ/bit

The physical unclonable function (PUF) can generate a unique identifier for each chip, ideal for key generation and chip anti-counterfeiting. The reliability of PUF is paramount, and therefore is one of the significant challenges for PUF design. This brief proposes a novel SRAM- and Inverter-based PUF (SI PUF) that can operate as either an SRAM PUF or an inverter PUF, depending on the input configuration signal. A zero-overhead bit configuration strategy (BCS) is proposed to enhance the reliability of PUF. Moreover, the working voltage of the sub-threshold level and the well-designed discharge stage ensure that our SI PUF can operate with low power consumption. The tested results of chips fabricated in 40-nm CMOS show that our SI PUF has only 0.0053% of the worst bit error rate (BER) under working conditions of −50 to 125°C and 0.75 to 1.5V, with 0.073/0.042 pJ/bit of power consumption. The low BER and energy overhead illustrate that our SI PUF is more suitable for resource-limited devices compared to DAC 2022 and JSSC 2020.