A blockchain-enabled collaborative intrusion detection framework for SDN-assisted cyber-physical systems

Cyber-physical systems (CPS) play an important role in our daily lives, such as automotive, medical monitoring, smart grid, industrial control systems and so on. CPS typically consists of three main components: sensors, aggregators and actuators. Recently, Software-Defined Networking (SDN) has been applied to CPS for achieving optimal resource allocation and Quality of Service, forming a type of SDN-assisted CPS. To protect such environment, collaborative intrusion detection system (CIDS) is a major security solution, but it is vulnerable to insider threat, where a cyber-attacker can behave maliciously within the network. In this work, we focus on this challenge and investigate the use of blockchain technology that can ensure immutable data sharing without the need of a trusted third party. We introduce a blockchain-enabled collaborative intrusion detection framework for SDN-assisted CPS. In particular, we use challenge-based CIDS in the study and evaluate the proposed framework under both external and internal attacks. The experimental results demonstrate the viability and effectiveness of our blockchain-enabled framework.