A New Perspective of Inscribing Temporal Encryption on Spatial MPV Imprints for PUF Design

In Physical Unclonable Function (PUF) design, the imprint from chip manufacture is inscribed into its output as chip signature. For all PUF architectures, the signature currently only includes spatial information. The response bits are all individually generated, not temporally related in any way. In this work, a new perspective of mingling temporal encryption with spatial imprints and carving the result into response is presented. This is achieved by enrolling a group of sequentially ordered stimulants and feeding them to a pulse-train-synthesizing machine for creating a temporal regulation. The synthesizing machine is realized by the Time-Average-Frequency Direct Period Synthesis (TAF-DPS). By using a train of pulses as the base for PUF bitstream, instead of temporally unrelated individual bits, the resultant output contains both spatial and temporal messages from the chip. The goal is to enhance the PUF’s security level, making it more resistant to attacks. In this work, its principle is explained and a prototype for proof-of-concept is presented on an FPGA platform. Our aim is to present a new avenue for PUF design.