Design And Implementation Of High Security Test Circuit For Encryption Chip

In order to ensure product quality,testing is one of the most important steps in the integrated circuit(IC)manufacturing process.In order to facilitate testing,a scan chain design is proposed and widely adopted.However,while the scan chain technology improves the testability of the chip,it also provides a way for attackers to attack the chip,which greatly reduces the security of the chip.Differential cryptanalysis attack,as a typical side-channel attack method,seriously threatens the security of encryption chip.This paper proposes an adaptive scan chain technology based on plaintext analysis for differential cryptanalysis attacks,in which the plaintext analysis module stores all the plaintext entering the "static" scan chain into the memory of the plaintext analysis module,and analyzes whether the current plaintext and the plaintext in the memory satisfies the plaintext pair characteristics of differential cryptanalysis.Among them,the control circuit makes the plaintext analysis module work in the test mode.The plaintext analysis module analyzes the characteristics between the plaintext,and the change of the adaptive scan chain is controlled by the result of the plaintext analysis.The adaptive scan chain can be changed to a "static" scan chain or "dynamic" scan chains.This technology mainly ensures the security of the encryption chip from two aspects,firstly,an adaptive scan chain is proposed.Compared with the original scan structure,the adaptive scan structure causes the target of the differential cryptanalysis attack to switch during the attack and gets the response generated by multiple scan chains of different structures.In the end,the differential cryptanalysis attack fails due to the missing samples of the analysis attack.Secondly,the plaintext analysis module controls the adaptive scan chain transformation,so that the plaintext pairs that meets the characteristics of the differential cryptanalysis attack passes through different scan chains,and the attacker cannot use the Hamming distance of the plaintext pairs response.Perform security analysis on an adaptive scan chain based on plaintext analysis.Compared with the traditional scan chain,the adaptive scan chain technology based on plaintext analysis can effectively prevent the encryption chip test key from leaking,and the probability of being cracked is reduced at least 1.37*10122 times.Testability reduced by 0.89% and the overhead increased by about3.07%.