초록 열기/닫기 버튼
Scan-based design has been used normally to simplify the manufacturing test. However, the convenience brought by the design also becomes the weakness that increases the vulnerability of crypto chips. Many attacks have been proved effective to steal secret information stored inside chips through this structure. In this paper, we will propose a secure scan design with very low overhead and high security. The proposed scheme chooses some scan cells in the front part of the original scan chain to store the test key. The output of these scan cells will be transmitted to a multiple-input AND gate to realize authentication. If the input test key is incorrect, the data of the sub-chain in the front part of the scan chain will be shifted circularly and the values of those scan cells used to store the test key will be dynamically transmitted to the latter part of the scan chain to realize dynamic data obfuscation. The scheme excellently resists existing scan attacks.
