A Concealable RRAM Physical Unclonable Function Compatible with In-Memory Computing

Resistive random access memory (RRAM) has been widely used in physical unclonable function (PUF) design due to its low power consumption, fast read/write speed, and significant intrinsic randomness. However, existing RRAM PUFs cannot overcome the cycle-to-cycle (C2C) variations of RRAM, leading to poor reproducibility of PUF keys across cycles. Most prior designs directly store PUF keys in RRAMs, increasing vulnerability to attacks. In this paper, we propose a concealable RRAM PUF based on an RRAM crossbar array, utilizing the differential resistive switching characteristics of two RRAMs to generate keys. By enabling the reproducibility of PUF keys across cycles, a concealment scheme is proposed to prevent the exposure of PUF keys, thus enhancing the security of the RRAM PUF. Through post-processing operations, the proposed PUF exhibits high reliability over ±10% VDD and a wide temperature range from 248K to 373K. Furthermore, this RRAM PUF is compatible with in-memory computing (IMC), and they can be implemented using the same RRAM crossbar array.