Multibit-Generating Pulsewidth-Based Memristive-PUF Structure and Circuit Implementation

As Internet of Things (IoT) devices have evolved, physical unclonable functions (PUFs) have become a popular solution for hardware security. In particular, memristor devices are receiving attention as suitable candidates for reliable PUFs because they can be integrated into nano-cross point array circuits with ultra-high efficiency. However, it has been found that typical 1-bit generating PUFs consume too many challenge–response pairs (CRPs) to generate a single response. This issue has to be overcome to construct a strong and reliable PUF with a large number of valid CRPs. We suggest a bank design and quantizing entropy source method for constructing a multibit-generating PUF. In this paper, we propose a new pulsewidth-based memristive PUF (pm-PUF) architecture that incorporates analog memristor devices and a nano-cross point array. We describe the architecture’s circuit implementation and its operating process in detail. We also evaluate the inter and intra performances of the pm-PUF in terms of randomness, diffuseness, uniqueness, and steadiness to show that the proposed pm-PUF will be a promising solution for a high-density hardware security system.