Open-Source, End-to-End Auditable Tapeout of Hardware Cryptography Module

Increasing concerns about data security and back-doored encryption hardware highlight the necessity for fully auditable chip design and fabrication processes. A fully open-source, traceable manufacturing of a chip would allow a system integrator or end-user to check for tampering which may have potentially occurred during design or fabrication. In this paper, we present the first fully end-to-end open-source, silicon-proven cryptography chip, implementing the AES-256 symmetric cipher. We demonstrate our flow for design-space exploration, followed by a successful tapeout of our chip on the SKY130 process node using an open-source RTL-to-GDS pipeline. In addition, we present our methods for bringing up the silicon despite clocking issues, and results proving the functionality of our process. To foster reproducibility and extensibility, all steps from our work, including the fabricated GDS files, are released under an open-source license and are backed by fully-open toolchains.