NetCo: Reliable Routing with Unreliable Routers

Software-Defined Networks (SDNs) are typicallydesigned and operated under the assumption that the underlyingrouters (and switches) are trustworthy. Recent incidents, however, suggest that this assumption is questionable. The possibility ofincorrect or even malicious router behavior introduces a widerange of security problems. The problem is exacerbated by thefact that governments and companies do not have the expertisenor budget to build their own trusted high-performance routinghardware. This paper presents NetCo, an approach to build securerouting using insecure routers. NetCo is inspired by the robustcombiner concept known from cryptography, and leveragesredundancy to compile a secure whole from insecure parts. Wepresent the basic design of NetCo, and report on a prototypeimplementation in OpenFlow.