Trusted Lightweight Communication for IoT Systems Using Hardware Security

This paper explores cutting-edge techniques for protecting cryptographic keys in Internet of Things (IoT) systems based on web protocols. In this context, we evaluated the use of security hardware with application-layer encryption on top of the Constrained Application Protocol (CoAP) for communication between constrained devices and cloud middleware. More precisely, we propose to protect keys against tampering on devices with the help of a secure element and to use memory isolation techniques, such as those provided by Intel CPUs using Software Guard Extension (SGX), on middleware. If properly implemented, this enables privacy-preserving services where even the service provider is unable to decipher exchanged data. Finally, we validated this solution on constrained nodes by measuring performance and energy requirements on an ultra-low-power microcontroller connected to a commercial secure element.