Moving Target Defense in SDN-enabled EV Charging Network
Software-Defined Networking (SDN) is emerging as a promis- ing technology for EV Charging infrastructure (EVCI) since it enables flexible, programmable control of EVCI networks, yet its security gain to EVCI remains underexplored. SDN-enabled EVCI faces an increas- ing number of cyber threats arising from the convergence of IT and OT components; in particular, low-rate Denial-of-Service (DoS) attacks. Ear- lier works identify a trend toward low-rate attacks in OT networks that may exhaust SDN switch flow tables and which can result in disabling the entire charging sites without triggering volume-based defenses. In this paper, we propose CS-SHIELD, a Moving Target Defense mecha- nism for SDN-enabled EVCI communication. We showcase the imple- mentation of the proposed mechanism that detects malicious flow table rules via cross-layer identity verification and responds by reassigning virtual IP addresses to all active chargers. Experiments on an emulated SDN testbed with a real charging protocol implementation demonstrate that CS-SHIELD maintains full site availability under attack, responds quickly, adds only a negligible delay under normal conditions. The reas- signing (shuffle) approach at each reaction makes the earlier reconnais- sance knowledge by the attacker rendered worthless.