物理不可克隆函数(PUF)作为一种可有效地应对硬件安全问题的电路结构, 在近些年得到了广泛的关注。环形振荡器(RO) PUF由于不需要完全对称的布线方式, 因此被认为是最理想的PUF结构之一。现有的RO PUF设计愈加复杂且需要“硬宏”来固定电路, 这导致PUF的移植性很差。文章利用FPGA中固有的进位逻辑资源实现RO PUF, 通过将3个进位逻辑中的11个异或门级联, 经配置实现11阶振荡环, 有效解决了可移植性问题, 避免了使用“硬宏”来固定电路。采用Xilinx Spartan-6, 对提出的结构进行实验。实验结果表明, 设计的RO PUF实现了50.65%的均匀性、48.48%的唯一性和1.56%的误码率。该设计方法具有易于实现、资源占用形式单一、无需手动布局布线等特点。

Physical Unclonable Function (PUF), as a circuit structure that can effectively deal with hardware security issues, has received extensive attention in recent years. Among them, the Ring Oscillator (RO) PUF does not require a completely symmetrical wiring method, so it is considered to be one of the most ideal PUF structures. However, the existing RO PUF design is more complicated and requires "hard macros" to fix the circuit, which results in poor portability of PUF. A RO PUF was implemented by using the inherent carry logic resources in FPGA in this paper. By cascading 11 XOR gates in 3 carry logics, the 11th-order oscillation ring was configured to solve the problem of portability and to avoid the use of "hard macros" to fix the circuit. The proposed structure was tested by using Xilinx Spartan-6. Experimental results showed that the proposed RO PUF achieved an uniformity of 50.65%, an uniqueness of 48.48% and a bit error rate of 1.56%. At the same time, this design had the characteristics of easy implementation, single resource occupation, and no manual layout.