On hardware acceleration of quantum-resistant FOTA systems in automotive

The Firmware Over-The-Air (FOTA) technology aims at updating the firmware of mobile computing devices via wireless. In the automotive industry, FOTA can keep the firmware of the various electronic controllers up-to-date without any manual intervention, so that to improve the operational performance and quickly fix the security vulnerabilities of vehicles. Of course, FOTA must avoid that a malicious party installs vulnerable or backdoored firmware on electronic controllers, which may lead to safety risks for the driver. It follows that a FOTA management system must guarantee the integrity and authenticity of all the firmware updates. While these security requirements are generally guaranteed by means of digital signatures, the advent of quantum computing is making traditional signature schemes increasingly vulnerable. Large-scale quantum computers able to break RSA and ECDSA could appear during the long lifetime of vehicles that are now in production, which can often reach two decades. In this paper, we experimentally evaluate the performance from an automotive FOTA perspective of Crystals-Dilithium and Falcon, two quantum-resistant lattice-based digital signature schemes that have been selected in 2022 by the NIST Post-Quantum Cryptography standardization process, and that represent the most probable choices for the future security technology. In particular, we evaluate the running time of various cryptographic operations performed by Uptane, which is a standard for automotive FOTA systems by the IEEE Industry Standards and Technology Organization, on three reference hardware architectures representing different classes of electronic control units. By means of experiments we also highlight that the hashing function is the primary limiting factor for the performance of automotive FOTA and, consequently, is the most convenient component to accelerate in hardware to improve FOTA execution time. Finally, we propose a hardware accelerator for SHAKE, the hash function used by both Crystals-Dilithium and Falcon, and experimentally evaluate the performance improvement that it brings about in automotive FOTA operations.