Abstract: The new generation of wireless sensor networks that is known as the internet of things enables the direct connection of physical objects to the internet using microcontrollers. In most cases, these microcontrollers have very limited computational resources. In this study, we investigate the access control solution for the IETF standard draft constrained application protocol using the datagram transport layer security protocol for transport security. We use the centralized approach to save access control information in the framework. Since, the public key cryptography operations might be computationally too expensive for constrained devices we build our solution based on symmetric cryptography.