Röpke, ChristianMeier, MichaelReinhardt, DelphineWendzel, Steffen2017-06-212017-06-212016978-3-88579-650-3Software-Defined Networking (SDN) is an emerging topic and securing its data and control plane is of great importance. The main goal of malicious SDN applications would be to compromise the SDN controller which is responsible for managing the SDN-based network. In this paper, we discuss two existent mechanisms aiming at protecting aforementioned planes: (i) sandboxing of SDN applications and (ii) checking for network invariants. We argue that both fail in case of sophisticated malicious SDN applications such as a SDN rootkit. To fill the corresponding security gaps, we propose two security improvements. The first one aims at protecting the control plane by isolating SDN applications by means of virtualization techniques. Compared to recent efforts, we thereby allow a more stringent separation of malicious SDN applications. The goal of the second proposal is to allow policy checking mechanisms to run independently from SDN controllers while minimizing hardware costs. Thereby, we improve SDN security while taking into account that correct functioning of policy checking can be manipulated by a compromised SDN controller.enText/Conference Paper1617-5468