This document evaluates different authentication mechanisms for control plane applications in software defined networks (SDNs). It discusses how a lack of trust between network applications and controllers is a challenge for SDN security. The document reviews several proposed authentication mechanisms and outlines a research proposal to evaluate these mechanisms under different performance scenarios in order to recommend a well-performing and reliable standard for the northbound API. It will use literature reviews and simulations with Mininet and NS3 to test authentication mechanisms on factors like the number of authenticated/unauthenticated applications over time.