Unleashing OpenTitan's Potential: a Silicon-Ready Embedded Secure Element for Root of Trust and Cryptographic Offloading
<|reference_start|>Unleashing OpenTitan's Potential: a Silicon-Ready Embedded Secure Element for Root of Trust and Cryptographic Offloading: The rapid advancement and exploration of open-hardware RISC-V platforms are driving significant changes in sectors like autonomous vehicles, smart-city infrastructure, and medical devices. OpenTitan stands out as a groundbreaking open-source RISC-V design with a comprehensive security toolkit as a standalone system-on-chip (SoC). OpenTitan includes Earl Grey, a fully implemented and silicon-proven SoC, and Darjeeling, announced but not yet fully implemented. Earl Grey targets standalone SoC implementations, while Darjeeling is for integrable implementations. The literature lacks a silicon-ready embedded implementation of an open-source Root of Trust, despite lowRISC's efforts on Darjeeling. We address the limitations of existing implementations by optimizing data transfer latency between memory and cryptographic accelerators to prevent under-utilization and ensure efficient task acceleration. Our contributions include a comprehensive methodology for integrating custom extensions and IPs into the Earl Grey architecture, architectural enhancements for system-level integration, support for varied boot modes, and improved data movement across the platform. These advancements facilitate deploying OpenTitan in broader SoCs, even without specific technology-dependent IPs, providing a deployment-ready research vehicle for the community. We integrated the extended Earl Grey architecture into a reference architecture in a 22nm FDX technology node, benchmarking the enhanced architecture's performance. The results show significant improvements in cryptographic processing speed, achieving up to 2.7x speedup for SHA-256/HMAC and 1.6x for AES accelerators compared to the baseline Earl Grey architecture.<|reference_end|>
@article{ciani2024unleashing,
    title={Unleashing OpenTitan's Potential: a Silicon-Ready Embedded Secure
  Element for Root of Trust and Cryptographic Offloading},
    author={Maicol Ciani, Emanuele Parisi, Alberto Musa, Francesco Barchi, Andrea
  Bartolini, Ari Kulmala, Rafail Psiakis, Angelo Garofalo, Andrea Acquaviva,
  Davide Rossi},
    journal={arXiv preprint arXiv:2406.11558},
    year={2024},
    doi={10.1145/3690823},
    archivePrefix={arXiv},
    eprint={2406.11558},
    primaryClass={eess.SY cs.SY eess.SP}
}