Vinko Davor, Miličević Kruno, Lukić Ivica, Köhler Mirko
Faculty of Electrical Engineering, Computer Science and Information Technology Osijek, Josip Juraj Strossmayer University of Osijek, Kneza Trpimira 2B, 31000 Osijek, Croatia.
Sensors (Basel). 2023 Jul 28;23(15):6769. doi: 10.3390/s23156769.
Blockchain-based applications necessitate the authentication of connected devices if they are employed as blockchain oracles. Alongside identity authentication, it is crucial to ensure resistance against tampering, including safeguarding against unauthorized alterations and protection against device counterfeiting or cloning. However, attaining these functionalities becomes more challenging when dealing with resource-constrained devices like low-cost IoT devices. The resources of IoT devices depend on the capabilities of the microcontroller they are built around. Low-cost devices utilize microcontrollers with limited computational power, small memory capacity, and lack advanced features such as a dedicated secure cryptographic chip. This paper proposes a method employing a Physical Unclonable Function (PUF) to authenticate identity and tamper resistance in IoT devices. The suggested PUF relies on a microcontroller's internal pull-up resistor values and, in conjunction with the microcontroller's built-in analog comparator, can also be utilized for device self-checking. A main contribution of this paper is the proposed PUF method which calculates the PUF value as the average value of many single PUF measurements, resulting in a significant increase in accuracy. The proposed PUF has been implemented successfully in a low-cost microcontroller device. Test results demonstrate that the device, specifically the microcontroller chip, can be identified with high accuracy (99.98%), and the proposed PUF method exhibits resistance against probing attempts.
如果基于区块链的应用程序被用作区块链预言机，那么就需要对连接的设备进行认证。除了身份认证外，确保抗篡改也至关重要，包括防止未经授权的更改以及防范设备伪造或克隆。然而，在处理诸如低成本物联网设备等资源受限的设备时，实现这些功能变得更具挑战性。物联网设备的资源取决于其所围绕构建的微控制器的能力。低成本设备使用的微控制器计算能力有限、内存容量小，并且缺乏诸如专用安全加密芯片等高级功能。本文提出了一种利用物理不可克隆功能（PUF）对物联网设备进行身份认证和抗篡改的方法。所建议的PUF依赖于微控制器的内部上拉电阻值，并且结合微控制器内置的模拟比较器，还可用于设备自检。本文的一个主要贡献是所提出的PUF方法，该方法将PUF值计算为许多单个PUF测量值的平均值，从而显著提高了准确性。所提出的PUF已在低成本微控制器设备中成功实现。测试结果表明，该设备，特别是微控制器芯片，可以高精度（99.98%）被识别，并且所提出的PUF方法具有抗探测尝试的能力。
