Proxied IBE-based key establishment for LLNs

Embedded systems devices have a wide application range, an instance of which is their use in Low-power and Lossy Networks (LLNs), which are anticipated to become one of the fundamental building blocks for the realisation of the Internet of Things (IoT). The security issues emerging from the requirement for Web accessibility can be fulfilled by appropriate cryptographic techniques, so as to secure the communicated information, supported by appropriate key exchange protocols, able to cope with the particular nature of such networks. The properties of Identity-Based Encryption (IBE) seem to match well the nature of such networks, thus an IBE-based key establishment protocol would be a good choice to be used in an LLN. However, severe limitations on those devices resources render deployment of expensive key establishment protocols inappropriate. Alternatives are therefore proposed such as offloading some of the computationally-intensive tasks to other, more powerful devices. Our IBE-based key establishment protocol enables a constrained node to exchange a shared secret with a remote party, that typically operates outside the node's network through an also non-constrained proxy node that undertakes the task of performing some of the expensive computations. The proposed key establishment scheme facilitates secure communications among embedded systems devices providing information and services to remote parties, towards the realisation of the Internet of Things.