Contiki is a small and resource-efficient OS for the IoT (Internet of Things). IPsec and IKEv2 are two standards used for secure communication over the Internet. Can they be implemented on Contiki using current hardware while still being interoperable with other Internet hosts? The question was answered by implementing and then evaluating the standards. A connection was established with another Internet host while measurements were made of ROM / RAM consumption, required processing time (i.e. energy consumption). By writing an efficient runtime and using Elliptic Curve Cryptography, I concluded that an interoperable implementation for Contiki was feasible. However, I also found that the standards -as such- were unsuitable for the IoT infrastructure due to their complexity and the fact that IPsec's policies are expressed in network layer primitives (i.e. unsuitable for networks with a dynamic topology).