A Novel FPGA-based LFSR PUF Design for IoT and Smart Applications

Silicon Physical Unclonable Functions (SPUFs) are used for extracting unique and random binary signatures from semiconductor chips. This paper introduces the first asynchronous LFSR based PUF; namely, the LFSR-PUF, that can be specifically implemented on a FPGA. The proposed ALFSR-PUF is derived from an asynchronous LFSR that uses D-latch/flip-flops and LUTs on an FPGA to generate a random clock by exploiting the inherent manufacturing process variations of the design primitives. The LFSR-PUF efficiently uses FPGA basic building blocks in each CLB to optimally occupy a very small area (two slices) in the FPGA. Besides design efficiency and area optimization, the challenge-response space is also increased. Consequently, an instantiation of more than one PUF instance is possible within each CLB. Experimental results on Xilinx Spartan-3E FPGA (90 nm) show that the generated signatures are both unique and reliable under varying temperature and voltage conditions.