DTLS Integration in oneM2M based on Zolertia RE-motes

Abstract

More and more Internet of Things (IoT) applications control essential aspects of our life and our environment. In this context, security becomes very important to avoid health risks or environmental damage. However, enabling security features on constrained devices is challenging. Lightweight Datagram Transport Layer Security (DTLS) has been designed for this context. We investigate the feasibility of running tinydtls, one of the implementations of DTLS, on the Zolertia RE-mote. Due to the computational limitations of this mote, the latest version of tinydtls implemented in Contiki OS cannot be executed for one of the two available cipher suites. We propose a solution by adding two processes to schedule the transmission of several handshake messages at prefixed times. We also redesign it to be platform independent. To verify the correct operation of the proposed solutions, we deploy them on a testbed made up of a server and a client, both running on RE-motes. To integrate DTLS based solutions running on constrained devices in a oneM2M framework, we develop an Interworking Proxy Entity (IPE) including a Datagram Transport Layer Security (DTLS) server in OM2M, which is an open source implementation of oneM2M. By doing so, we enable security in this horizontal IoT framework aiming at interoperability. To show the validity of our work, we set up a second testbed to evaluate the performance of the constrained devices in terms of processing and communication time, and energy consumption.