Benefits of edge computing include reduced latency and bandwidth savings, privacy-by-default and by-design in compliance with new privacy regulations that encourage sharing only the minimal amount of data. This creates a need for processing data locally rather than sending everything to a cloud environment and performing machine learning there. However, most IoT edge devices are resource-constrained in comparison and it is not evident whether current machine learning methods are directly employable on IoT edge devices. In this paper, we analyze the state-of-the-art machine learning (ML) algorithms for solving security problems (e.g. intrusion detection) at the edge. Starting from the characteristics and limitations of edge devices in IoT networks, we assess a selected set of commonly used ML algorithms based on four metrics: computation complexity, memory footprint, storage requirement and accuracy. We also compare the suitability of ML algorithms to different cybersecurity problems and discuss the possibility of utilizing these methods for use cases.