Correction of Bit-Aliasing in Memristor-Based Physically Unclonable Functions With Timing Variability

The dependence between the write time and process variation of a memristor was investigated as a candidate physically unclonable function (PUF). Such write-time-based approach requires exact timing control of the programming pulse to achieve well-balanced results as the source of randomness. However, exact timing control requires precise hardware, such as a high-frequency timer. Furthermore, the effects from other variability sources, such as the voltage and temperature, may degrade the quality of the PUF device operation. In this study, we introduce a method to enhance the bit-aliasing of a memristor-based PUF with write time variability considering the timing error. By exploiting the non-volatility and bidirectional operation of the memristor, the proposed method attempts to correct the timing error using extra programming pulses. The experiment results reveal that the proposed method reduces the bit-aliasing error by 75.44%.