Research On Chip Security Technology Based On Physical Unclonable Function

The rapid development of information technology is also accompanied by many security issues.As an important carrier of modern information technology,the research on chip security protection technology has become an important topic in the field of integrated circuits.The Physical Unclonable Function(PUF)refers to the process deviation of the manufacturing stage extracted from the chip as the unique hardware fingerprint of the chip.Aiming at the potential security issues in chip supply chain and chip data protection,this thesis studies the method of using physical unclonable functions to enhance chip security.The traditional RO PUF method,which produces one bit effective output by comparing two ROs,has a low utilization rate of frequency slave information,so this thesis studies a more efficient information extraction method.This thesis starts from the RO PUF circuit based on FPGA,and establishes the basic model of RO PUF delay according to the key parameters that determine the delay in the circuit.Based on the established delay model,this thesis analyzes the basic principle of the frequency-based high-order differential method,and points out the problem that the bit error rate of the differential results above the third order is relatively high.The method of summing first and then difference can extract additional 8 bits of effective information.After combining with the second and third order difference results of the high-order difference method,a total of 32 bits of output can be obtained.The experimental results show that the stability of the combined method is 99.15% with a uniqueness of 49.05%.Compared with the high-order differential entropy extraction method,the stability index is superior.Aiming at the malicious attacks that chips may suffer in each link of the supply chain,this thesis combines PUF and PKI technologies to establish a secure identity authentication system.The method was proposed by using hardware circuits such as PUF and BCH to provide a unique key for the chip,and issuing a digital certificate for the legal chip based on the key.The chip,key,and digital certificate are bound to each other.In the supply chain system,only legal chip of the certificate can pass the certification and enter the next stage.This thesis introduces the hardware and software structure and implementation principle of the authentication system developed based on Xilinx PYNQ.The experimental test results show that the original corresponding output bit error rate of the circuit is only 0.2%.After processing by the error correction circuit,the correct output can be guaranteed under different ambient temperatures,and it has good stability.Aiming at the risks that users' data and programs in Io T devices may be stolen and tampered with,this thesis designs a PUF-based security chip,and proposes PUF-based firmware protection and data encryption and decryption schemes.By combining PUF and digest algorithm,the authentication message and encryption key can be extracted from the chip,which are used for firmware authentication and user data encryption and decryption respectively.Using the PUF output randomness and unclonable characteristics,the chip can be stolen even if it is stolen by an attacker.Protect users' data security.This thesis mainly completes the front-end work of chip structure design,code implementation,logic synthesis,etc.,and analyzes the results of each work separately.