Lightweight Blockchain-Based Access Control for Smart IoT Devices

Due to the rapid expansion of smart cities, security threats have peaked in the form of cyber security threats especially in the case of IoT based access control system. In general, centralized access control mechanisms are the SOFT SPOTS for breaches of personal data and unauthorized access. This paper presents SecureBlock, a lightweight blockchain based framework to address the above challenges for decentralized and cyber resilient access control in the smart cities. SecureBlock employs hybrid consensus (PBFT + PoA) in order to provide tamper resistant, low latency and scalable authentication for intelligent IoT devices. The key functionality of the framework encompasses four layers: including (1) the IoT Security Layer for the real-time access authentication, (2) the Blockchain Layer for the distributed access logs, (3) the Threat Intelligence Layer for the AI based robust anomaly monitoring and (4) the Smart Contract Layer that deploys Cyber Resilient Smart Contract (CRSC) for the autonomous response to threats. Contrary to the typical Role Based Access Control (RBAC), or centralized OAuth, the SecureBlock authentication is real time, immutable, trustless — and consequently, extremely low risk of spoofing identity and intrusions.Hyperledger Fabric is used for the deployment of the blockchain and Flask & SQLite is used for IoT authentication with Python. The metrics such as authentication latency, transaction throughput (TPS) and energy consumption are analyzed. The results show that SecureBlock can achieve to authenticate up to 50 percent faster than the traditional blockchain models and reduce to up to 30 percent energy consumption. In addition, AI based anomaly detection in CRSC allows for high levels of cyber security with an accuracy greater than 90%. Thus, this research illustrates the application of blockchain in the area of smart cities, as a secure, decentralized and scalable platform to access control and thus resulting in a more cyber resilient smart city. Future work will be to deploy SecureBlock in real world urban environment and integrate machine learning adaptive secure policies into the next generation IoT cyber security for smart cities.