Research on Software Defined Network Security Model Based on Blockchain

With the wide application deployment of software defined networks, the security problems faced by software defined networks have become increasingly prominent. Nowadays, the security of SDN is gradually becoming an important factor restricting its development. At the application level, the main security problem faced by SDN lies in the imperfection of application mechanism and authority management; In the control layer, because the controller is the core node of the whole network, its main security problem is the single point failure of the controller. At the data forwarding layer, the main problem is that there is no good guarantee mechanism for the integrity of the flow rule information issued by the controller.[1] As a result, hackers can tamper with the flow table information of the AC machine. Yes, SDN traffic flows according to the attacker's intention, which leads to network function failure. In this paper, the main security problems faced by SDN will be solved from multiple dimensions based on the decentralized, trustworthy and self-willed characteristics of blockchain, which is a distributed database.