School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China.
Hubei Key Laboratory of Ferro &Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science , Hubei University , Wuhan 430062 , China.
Nano Lett. 2018 Nov 14;18(11):7211-7216. doi: 10.1021/acs.nanolett.8b03338. Epub 2018 Oct 29.
Information security is of great importance for the approaching Internet of things (IoT) era. Physically unclonable functions (PUFs) have been intensively studied for information security. However, silicon PUFs are vulnerable to hazards such as modeling and side-channel attacks. Here we demonstrate a magnetic analogue PUF based on perpendicularly magnetized Ta/CoFeB/MgO heterostructures. The perpendicular magnetic anisotropy originates from the CoFeB/MgO interface, which is sensitive to the subnanometer variation of MgO thickness within a certain range (0.6-1.3 nm). When the MgO layer is thinned, a thickness variation resulting from ion milling nonuniformity induces unclonable random distributions of eas y-axis magnetization orientations in heterostructures. The analogue PUF can provide a much larger key size than a conventional binary-bit counterpart. Moreover, after the thinning process, the unique eas y-axis magnetization orientation in each single device was formed, which can avoid setting random states to realize low power consumption and high-density integration. This magnetic PUF is a promising innovative primitive for secret key generation and storage with high security in the IoT era.
信息安全对于即将到来的物联网 (IoT) 时代至关重要。物理不可克隆函数 (PUF) 已被广泛研究用于信息安全。然而，硅 PUF 容易受到建模和侧信道攻击等危害。在这里，我们展示了一种基于垂直磁化 Ta/CoFeB/MgO 异质结构的磁模拟 PUF。垂直磁各向异性源于 CoFeB/MgO 界面，该界面对 MgO 厚度在一定范围内（0.6-1.3nm）的亚纳米变化敏感。当 MgO 层变薄时，离子铣削不均匀导致的厚度变化会导致异质结构中易轴磁化方向的不可克隆随机分布。模拟 PUF 可以提供比传统二进制位对应物大得多的密钥大小。此外，在减薄工艺之后，每个单个器件中形成了独特的易轴磁化方向，这可以避免设置随机状态以实现低功耗和高密度集成。这种磁性 PUF 是物联网时代用于生成和存储机密密钥的一种很有前途的创新基元，具有很高的安全性。
