PISA: PUF-Based IoT Swarm Attestation Protocol

Internet of Things (IoT) systems comprise a large number of resource-constrained edge devices that collaborate to serve application tasks. Remote attestation refers to checking the integrity of the software onboard the individual devices to ensure that it is not tampered with or infected by malware. Swarm attestation refers to collective integrity check of multiple devices as a means to cope with the large network size. Yet, existing swarm attestation schemes fall short of identifying the suspected devices and/or achieving important security properties. To fill the technical gap, this article proposes PISA a lightweight attestation and aggregation framework utilizing physical unclonable functions (PUFs) as the Root-of-Trust in both digest generation and aggregation, within a multiprover network. The objective is to ensure the privacy and integrity of individual device attestation reports, verifying the authenticity of attestation requests across the network while also identifying the devices that fail the verification. PISA employs a network partitioning algorithm and optimized aggregation paths to amortize overhead and support scalability. The security properties of PISA are rigorously analyzed. The validation results show that PISA outperforms competing schemes, offering enhanced runtime and bandwidth efficiency and reduced energy consumption.