A SC PUF Standard Cell Used for Key Generation and Anti-Invasive-Attack Protection

By using metal blocks as the protective coating, placing the sensitive signals in last but second metal (LSM), integrating a low-cost one-time programming (OTP) cell in each PUF unit, the proposed switched-capacitor (SC) PUF can both provide sensitive anti-invasive-attack protective coating and stable key for the security chip. Moreover, the circuit parameters and the layout implementation of the SC PUF unit are all compatible with other digital standard cells, which greatly facilitates the integration of SC PUF unit in the security chip by using digital design flow when its function, timing, power, and layout views are characterized using commercial timing and layout extraction tools. The anti-invasive-attack ability, stability, and digital design flow compatibility of the proposed SC PUF standard cell are verified in a security chip by using a standard 0.18- \mu \text{m} CMOS process. The measured bit error rate, bias, average intra-die HD, and average inter-die HD of output keys after OTP is