25.2 A Reconfigurable RRAM Physically Unclonable Function Utilizing Post-Process Randomness Source With −6 Native Bit Error Rate

Physically unclonable functions (PUFs) are promising primitives for hardware security with wide applications in the lnternet of Things (IoT), e.g., authentication and encryption key generation [1, 2]. Most silicon PUFs utilize process variability of semiconductor manufacturing [1, 3, 4]. These implementations are sensitive to variations in operating conditions (e.g., supply voltage and temperature variations) and undergo significant native bit-error-rates (N-BERs). Thus, additional stabilizing strategies, such as ECC, majority voting, and masking, are necessary. Furthermore, the PUF key after enrollment cannot be changed in prior implementations [1–5]. This could be unsafe if the PUFs are repeatedly used in insecure environments, as PUFs suffer from the challenges of ownership change and overuse (Fig. 25.2.1).