Increasing stability and distinguishability of the digital fingerprint in FPGAs through input word analysis

Field programmable gate arrays (FPGAs) have become increasingly popular in circuit development due to their rapid development times and low costs. With their increased use, the need to protect their intellectual property (IP) becomes more urgent. The digital fingerprint accomplishes this by creating a unique identification (ID) for each FPGA. In this research, we propose methods to dramatically increase the stability and robustness of the digital fingerprint ID by the proper choice of input sequences. We also show that by properly choosing the input word, we can significantly increase the DF resistance to operating temperature changes.