Lightweight, Dynamic and Energy Efficient Security Mechanism for constrained IoT devices using CoAP

Security and privacy issues are a great challenge in IoT systems. IoT security, of course, depends by the security level offered by communication protocols. In this paper we focus on a secure CoAP (Constrained Application Protocol) proposing a lightweight security mechanism for IoT devices characterized by limited resources. We introduce the feature of dynamic security, through a security levels scheme, to face the problem of devices heterogeneity and to provide more flexibility in choosing the security parameters that best suit the current state of the device, in terms of resources availability. Energy aspects are considered to evaluate the impact of the security on the devices' resources and to estimate the energy saving achieved by the dynamic approach. Performance evaluation has been led out comparing the dynamic Security supported by security levels with the classical secure COAP based on DTLS.