Blockchain as a Service for Software Defined Networks: A Denial of Service Attack Perspective

Software defined networking (SDN) is one of the most popular network technologies which provides an adaptive, agile and flexible network management and visibility. Although SDN architecture provides manifold benefits but on the same time its dependence on a logically centralized controller lead to the single point of failure. An attacker can easily capture the any forwarding device and restrict the availability of the controller using different prevalent attacks. Distributed denial of service (DDoS) is one of the most popular attack of this category which is quiet prevalent in SDN. Here, the aim of the attackers is to inject false script in the open flow tables through malicious switches which multiply exponentially. Therefore, in this paper, a blockchain as a service framework has been presented wherein BlockSDSec model is designed to provide security as a separate service for the SDN architecture. This work provides a mechanism to prevent the threats of DDoS at the switch level by embedding an security using blockchain onto the interaction channels of data and control planes. The load balancing at the controller level is achieved using a virtual controller. The proposed scheme is simulated using MiniNet Emulator to analyze the delay originating from usage of blockchain.