D Flip-flop Based Physical Unclonable Functions

With the progress of semiconductor technology and the continuous development of integrated circuit design,IC-related products have gradually become a necessity in daily life.The emergence of electronic products leads to the emergence of number of important information,so that information security faces severe challenges.Traditional cryptography-based methods have been unable to adapt to the application in the field of integrated circuits due to their own limitations.At the same time,the proposed physical unclonable function(PUF)has become an important method for this problem.The physical unclonable function takes advantage of the inherent biases in semiconductor fabrication processes to produce unique and stable response results.Over the past decade,due to the rapid development of physical unclonable function,more and more new structures of PUF were proposed.However,due to FPGA's own limitation,which is known as a flexible platform in the field of integrated circuits,most of the delay based PUF structures can not have a good performance in FPGA devices.This becomes a serious impediment to the implementation on FPGA platform of PUF.Based on the study of the delay based PUF in FPGA devices and the analysis of the characteristics of metastability of D flip-flop,a new structure of D flip-flop based physical unclonable function is proposed.The circuit of hard macro in FPGA makes the delay interference caused by FPGA eliminated completely and the randomness of the setup time of two D flip-flops can be enlarged.This solves the problem of low performance of delay based PUF in FPGA devices,and greatly improves the security and stability of PUF.The measurement results of the PUF also showed its good uniqueness,reliability and uniformity.The realization of D flip-flop based PUF in FPGA devices brings great flexibility to the design of integrated circuit,and its security,stability and non-duplication provide a new solution for information security.