A Cross-domain Collaborative DDoS Defense Scheme Based on Blockchain-SDN in the IoT.

At present, using a large number of unsafe IoT devices to form botnets and launching DDoS attacks have become one of the main threats to IoT security. However, most of the existing DDoS attack defense methods are limited to being implemented within a single controller management network domain. In fact, many IoT devices that attackers build botnets are usually located in the jurisdiction of different controllers. Therefore, a mechanism is needed for each domain to cooperate with each other and share information about the attack source, so as to realize the defense against DDoS attacks across multiple domains. Blockchain technology's decentralization and group trusted collaboration mechanism provide a new method for solving cross-domain DDoS attack defense. This article combines SDN and blockchain with IoT, and proposes a cross-domain collaborative DDoS defense scheme based on blockchain and SDN architecture. It allows multiple SDN-based domains to collaborate with each other and share attack source information in a decentralized manner, making collaborative DDoS attack defense across multiple domains more flexible. Experimental results show that the defense mechanism has flexibility, feasibility, and safety.