The invention relates to a
secure communication method for a distributed multi-
granularity controller of a
software defined network based on proxy, and belongs to the technical field of inter-domain
secure communication of a multi-domain SDN. The method comprises the following steps: designing architecture of a distributed multi-
granularity security controller, wherein the architecture comprises a message data packet format between controllers, establishing a communication tunnel via the connection between a controller domain and inter-domain proxies and the connection between the inter-domain proxies, and completing neighbor discovery between the controller, two-step identity
authentication and encrypted transmission to achieve
direct communication between multi-domain network controllers. In the communication method, the infrastructure is based on the security controller and the inter-domain proxies, a message of a control plane is released to a data plane by the inter-domain proxies for transmission, and thus the
communication problem between independent control planes is solved; and meanwhile, the two-step
authentication scheme of communication of the controller is given based on a
challenge response mechanism and a DTLS protocol, service supply can be defended and refused, and the identity
authentication is completed to improve the security.