PortSec: Securing Port Knocking System using Sequence Mechanism in SDN Environment

Port knocking provides an added layer of security on top of the existing security systems of a network. A predefined port knocking sequence is used to open the ports, which are closed by the firewall by default. The server determines the valid request if the knocking sequence is correct and opens the desired port. However, this sequence poses a security threat due to its static nature. This paper presents the port knock sequence-based communication protocol in the Software Defined network (SDN). It provides better management by separating the control plane and data plane. At the same time, it causes a communication overhead between the switches and the controller. To avoid this overhead, we are using the port knocking concept in the data plane without any involvement of the SDN controller. This study proposes three port knock sequence-based protocols (static, partial dynamic, and dynamic) in the data plane. To test the protocol in SDN environment, the P4 implementation of the underlying model is done in the BMV2 (behavioral model version 2) virtual switch. To check the security of the protocols, an informal security analysis is performed, which shows that the proposed protocols are secured to be implemented in the SDN data plane.