The utilization of power-up values in SRAM cells to generate PUF responses for chip identification is a subject of intense study. The cells used for this purpose must be stable, i.e., the cell should always power-up to the same value (either ‘0’ or ‘1’). Otherwise, they would not be suitable for the identification. Some methods have been presented that aim at increasing the reliability of SRAM PUFs by identifying the strongest cells, i.e., the cells that more consistently power-up to the same value. However, these methods present some drawbacks, in terms of either their practical realization or their actual effectiveness in selecting the strongest cells at different scenarios, such as temperature variations or when the circuits have suffered aging-related degradation. In this work, the experimental results obtained for a new method to classify the cells according to their power-up strength are presented and discussed. The method overcomes some of the drawbacks in previously reported methods. In particular, it is experimentally demonstrated that the technique presented in this work outstands in selecting SRAM cells that are very robust against circuit degradation and temperature variations, which ultimately translates into the construction of reliable SRAM-based PUFs.

利用SRAM单元中的上电值产生PUF响应以进行芯片识别是一个深入研究的主题。用于此目的的单元必须稳定，即，单元应始终加电至相同的值（“ 0”或“ 1”）。否则，它们将不适合识别。已经提出了一些旨在通过识别最强的单元（即，更一致地加电到相同值的单元）来提高SRAM PUF可靠性的方法。但是，这些方法在其实际实现或在不同情况下（例如温度变化或电路遭受与老化相关的退化）选择最强电池方面的实际有效性方面存在一些缺陷。在这项工作中，提出并讨论了一种根据功率增强强度对细胞进行分类的新方法的实验结果。该方法克服了先前报道的方法中的一些缺点。特别是，通过实验证明，这项工作中介绍的技术在选择对电路性能下降和温度变化非常稳定的SRAM单元方面表现出色，这最终转化为可靠的基于SRAM的PUF的构造。