Practical security analysis for the constrained node networks: Focusing on the DTLS protocol

With the explosive popularity of the Internet of Things (IoT) which enables the global connectivity of surrounding objects, the importance of security and privacy is getting more recognized recently. Unlike traditional network entities, devices in IoT normally have constrained resources, which makes it hard to provide full-featured security. To provide a secure channel between Constrained Nodes (CN), Datagram Transport Layer Security (DTLS) is currently used as the de facto security protocol to secure application messages. This paper introduces the practical analysis of DTLS focusing on the Constrained-Node Networks (CNN). We have investigated security considerations for CNN and analyzed the performance of DTLS with a real implementation on an IoT connectivity platform named SNAIL (Sensor Networks for an All-IP World). For a more practical approach, we have additionally implemented the Lightweight Machine to Machine (LwM2M) protocol on SNAIL and evaluated the security functionalities' network performance. Our various evaluations have shown the impact of embedded cryptography, multi-hop topology, link-layer quality and other constraints. This research would give a comprehensive guidance to whom that wants to provide secure services efficiently to their potential users.