Secure Scan Structures And Secure Scan Methods For Crypto Chips

With the rise of cloud computing and the Internet of things, the breadth and depth of the Internet continues to expand, the network information security has become an increasingly important technology and social issues. Crypto chips is the basis of network security, if the security of crypto chips can not granted, the network information security is nothing.As the most currently accepted design for test structure, scan test structure is widely used in various types of digital chips including crypto chips. Scan test structure provide these chips with sufficient test coverage at an acceptable test cost, which ensure the reliability of various electronic systems. However, in these years, some researches showed that it might be misused as a path of side-channel attack to leak out the secret information of crypto chips.To address such a challenge, a feedforward xored secure scan structure is proposed. The scan structure conducts an input/output linear transformation on the test patterns to hardware encrypt the test patterns by introducing feedforword xored secure scan flip-flops in the structure; and then the security of the structure is analyzed and its test pattern generation algorithm is presented.Experimental results show that the structure can be used as an effective countermeasure against scan-based side-channel attack and reset attack, while high test coverage of the traditional scan structure is maintained. The structure resolve the conflict of the testability and the security of crypto chips.