Information Classification Strategy for Blockchain-based Secure SDN in IoT Scenario

1As people's dependence on the Internet increases, traditional network architectures with rigid characteristics will gradually fail to meet all demands. It has higher flexibility and provides a convenient platform for technologies and concepts such as the Internet of Things, cloud computing, and network function virtualization. However, the flexibility of SDN also brings various security risks. For example, (i) the fault-tolerant mechanism is not sound enough, if communication with the controller fails, then the forwarding layer device may not be able to obtain the routing information; (ii) more complex applications have lower reliability, and new applications may have hidden unknown vulnerabilities; and (iii) the open programmable interface is also in danger of being illegally intruded. To address these problems, this paper proposes a blockchain-based SDN monitoring system that uses the information invariance of the blockchain and a distributed consensus mechanism to enhance the security of SDN. It also uses the distributed storage feature of P2P network to enhance the disaster resistance of SDN. In addition, in order to prevent stakeholders and non-professionals from affecting the reliability of supervision, we use multicast instead of broadcasting for information transmission. While taking full advantage of the functions of flow control and protocol deployment, the overall security of the system can be effectively improved. Encouragingly, the simulation results show that the scheme can effectively control the traffic and balance the load at the same time. Furthermore, we also outlined some challenges and future research directions.