Organic Current Mirror PUF for Improved Stability Against Device Aging

Physically unclonable functions (PUFs) are important primitives in the field of hardware security. Their applications can be further broadened if PUFs are fabricated using organic thin-film transistors (OTFTs). Examples include smart packaging that proves authenticity of a contained product and privacy protection for information gathered by organic sensors. This paper proposes an organic current mirror PUF (OCM-PUF) that can be fabricated on a flexible substrate. The proposed OCM-PUF adapts a current mirror structure to achieve self-compensation of the device performance degradation of OTFTs, which is unavoidable in most organic materials. Two types of OCM-PUFs were designed using a low supply voltage OTFT to evaluate the metrics as a PUF. The fabricated OCM-PUFs maintained a reliability of nearly 95% over few weeks, thereby showing that the proposed PUF achieved a high tolerance against response changes caused by device aging.