A Zero Trust Architecture employing Blockchain and Ring Oscillator Physical Unclonable Function for Internet-of-Things

The Internet-of-Things (IoT) constitute a network of millions of devices interconnected through the internet to facilitate data transfer amongst themselves. This network, along with the devices involved in it, is vulnerable to various cyber threats, due to its high utilization. Consequently, notable research is being conducted to enhance the security of IoT devices and networks. The state-of-the-art, however, still lacks a reliable solution against insider threats in the IoT network. This paper introduces a zero-trust architecture implemented by blockchain and ring oscillator physical unclonable functions (ROPUFs) to bolster the security of IoT devices and networks. The zero trust policies are inspired by the tenets outlined by the National Institute of Standards and Technology. The unique challenge response pairs generated by ROPUFs are utilized to validate the FPGAs. Blockchain features, such as smart contracts, tracking and tracing capabilities, and immutability, are employed for user authentication and access control. To assess the successful implementation of the proposed technique, a case study of an image file transfer between two users is presented. This scenario is effectively simulated using the Ganache framework provided by the Truffle suite. For implementing the ROPUF, Artix 7 Xilinx FPGA mounted on Nexys 4 Digilent board is used. The blockchain smart contract for this investigation is developed using the Solidity language.