SALAD: Secure and Lightweight Attestation of Highly Dynamic and Disruptive Networks

Today, tiny embedded Internet of Things (IoT) devices are increasingly used in safety- and privacy-critical application scenarios. In many of these scenarios, devices perform a certain task collectively as a swarm. Remote attestation is an important cornerstone for the security of these IoT devices, as it allows to verify the integrity of the software on remote devices. Recently proposed collective attestation protocols are able to attest entire device swarms in an efficient way. However, these protocols are inefficient or even inapplicable when devices in the network are mobile or lack continuous connectivity. This work presents SALAD, the first collective attestation protocol for highly dynamic and disruptive networks. SALAD uses a novel distributed approach, where devices incrementally establish a common view on the integrity of all devices in the network. In contrast to existing protocols, SALAD performs well in highly dynamic and disruptive network topologies, increases resilience against targeted Denial of Service (DoS) attacks, and allows to obtain the attestation result from any device. Moreover, SALAD is capable of mitigating physical attacks in an efficient manner, which is achieved by adapting and extending recently proposed aggregation schemes. We demonstrate the security of SALAD and show its effectiveness by providing large-scale simulation results.