A Sequence-Dependent Configurable PUF Based on 6T SRAM for Enhanced Challenge Response Space
Lu Lu, Tony Tae-Hyoung Kim · 2019
This work proposes a 2D sequence-dependent PUF based on SRAM. It expands challenge to response pairs (CRPs) by the order of rows(sequence length − 1) × columns(sequence length − 1) for reliable authentication. This is achieved by configuring the sequence of SRAM cell selection. Each bit cell has a vertical word-line and a horizontal word-line to utilize the orthogonal word-lines to connect four cells simultaneously to generate one bit data. The proposed technique allows us to generate multiple data maps from one chip. This non-linear behavior also makes the chip more secure. A test chip was fabricated in 65 nm CMOS technology with the area of area is 12580 µm2. The bit error rate is 3% at the nominal point (0.8 V/20°C) and the inter-hamming distance between chips is 0.497. The hamming distance of 0.427 was measured when using the same sequence length with different orders.