Remote Attestation for Low-End Prover Devices with Post-Quantum Capabilities

Remote attestation is a well-established interactive technique to establish trust in the realm of connected devices. It allows a Prover device to attest its platform integrity to a Verifier device. Existing remote attestation protocols rely on classical asymmetric cryptography, which are too heavy for low-end Prover devices, and vulnerable to quantum attacks (a serious concern due to the long lifespan of IoT devices). Hash-Based Signatures (HBS) offer attractive performance and have capabilities to defeat quantum attacks. This paper presents several contributions in this context. First, we present an efficient remote attestation protocol that requires the Prover to perform only one-time HBS operations, which are very lightweight. Our protocol also proposes robust embedded techniques to refresh one-time keys that allow multiple attestations. Second, we present a simpler construction based on multi-time HBS scheme which does not depend on a trusted-third-party. Third, to demonstrate the feasibility of our protocols, we developed prototypes based on state-of-the-art HBS schemes (XMSS and WOTS+) for highly constrained platforms (Arduino 101) in both classical and post-quantum security settings. Finally, we present a comprehensive comparison between these strategies, including guidance on suitable use cases for each one of them. To summarize, our work demonstrates the feasibility of modern HBS constructions for remote attestation of highly-constrained devices.