Brave-sdn: blockchain-reliant authentication for versatile east–west bound in distributed SDNs

The emerging concept of Software Defined Networks (SDN) involves separating the data and control planes, offering a global network view and making it programmable. Despite its benefits, deploying SDN within large, complex, and highly salable networks introduces new security challenges. These include a potential single point of failure in the control plane, the possibility of malicious flows from applications, and the exposure of network-wide resources through a vulnerable channel between the control plane and the data plane. In distributed SDN architectures, the security of various channels to exchange network management information is crucial for ensuring reliable network Operations. This issue may be addressed by integrating appropriate authentication mechanisms. In this paper, we propose a novel authentication scheme that combines blockchain technology and identity-based cryptography to improve the security of distributed SDNs. This scheme ensures secure communication on the east/west-bound channels by achieving decentralized, lightweight, and robust authentication and preventing malicious entities from participating in network operations. The security of the proposed scheme is thoroughly analyzed through a formal security analysis using AVISPA.