Research on High-Security and High-Reliability PUF OTP Controller

Physically unclonable functions (PUF) one time programmable (OTP) device is increasingly being widely used in IoT chips and AI chips. Based on PUF-based OTP, this paper designs a high-security and high-reliability OTP controller. In terms of storage security, 1) key encryption storage. The keys stored in the OTP are all encrypted values through PUF fingerprinting, and the keys are decrypted and used before their use; 2) physical isolation of the key area. The CPU can only use the keys through the key management process but cannot directly read the keys; 3) SM4 encryption and decryption will automatically clear the intermediate values during the operation, so that the traces of key usage are automatically erased after the key is used. In terms of reliability, by storing the SM3 hash value of each key in the OTP, after reading the key, the hash value of the key is compared to determine whether the key is complete, thereby ensuring that the stored value of the key before decryption is correct and unchanged. In terms of testing, this paper greatly simplifies the complexity and difficulty of automatic test equipment (ATE) testing for PUF OTP by designing the JTAG access register circuits and test acceleration circuits, which greatly simplifies the complexity of ATE testing and reduces the execution time of ATE testing, saving testing costs.