The Long Road to Open Silicon: How OpenTitan and the Rise of Secure Roots of Trust are Reshaping the Semiconductor Industry

The 2018 Hot Chips conference served as a pivotal moment for the future of hardware security. It was there that Google hardware engineers first pulled back the curtain on "Titan," a custom-designed chip intended to establish a silicon root of trust (RoT) within the company’s massive server fleet. At the time, the semiconductor industry was still reeling from the discovery of the Spectre and Meltdown vulnerabilities, which had exposed fundamental flaws in the way modern processors handle data. The industry was desperate for a new approach to security—one that began at the very base of the hardware stack.

Google’s vision, however, extended beyond its own data centers. The engineers spoke of a future where this technology would be available as an open-source offering, marking a significant milestone in the then-nascent open-silicon movement. Leading this ambitious charge was Dominic Rizzo, who served as the technical lead manager for the effort at Google for five years. Rizzo’s mission was not just to build a secure chip, but to solve a fundamental problem facing cloud providers: the inconsistency of hardware security across a fragmented supply chain.

Reflecting on those early days, Rizzo recalls how he pitched the concept internally. The primary selling point for Google was the realization that their security posture was becoming "lumpy" because they were purchasing a vast array of heterogeneous hardware for their cloud operations. Each vendor had its own proprietary security implementations, making it difficult to maintain a uniform standard across the infrastructure. OpenTitan was conceived as the first truly credible, well-resourced, "do-it-right-from-scratch" open-source silicon project, designed to smooth out those lumps and provide a transparent, verifiable foundation for trust.

For Rizzo, OpenTitan was the beginning of a decade-long journey to push the "open silicon rock" up a very steep hill. After leaving Google in 2023, he transitioned to the role of project director for OpenTitan at lowRISC, the official maintainer and host of the project. That same year, he co-founded zeroRISC, a startup where he now serves as CEO, with the explicit goal of driving broad commercial adoption of open-silicon RoT.

The movement gained significant momentum in May when zeroRISC, alongside industry giants including Qualcomm, Meta, and Analog Devices, as well as the Max Planck Institute for Security and Privacy, launched Pavona. Operating under the auspices of the nonprofit standards consortium GlobalPlatform, Pavona is chaired by Rizzo and functions as a neutral ecosystem for designing secure hardware. The project is modeled after successful open-source software initiatives like the Yocto Project and the Zephyr Project, providing a framework where competitors can collaborate on non-differentiating but critical security components.

Pavona is particularly notable for its focus on the future of encryption. It includes a production-stage post-quantum cryptography (PQC) stack that supports a variety of modern algorithms, such as ML-KEM, ML-DSA, and SLH-DSA. This composable platform allows organizations to build their own hardware roots of trust and chip subsystems with the confidence that they are protected against the emerging threats of the quantum computing era.

The logic behind open silicon mirrors the arguments that propelled open-source software to dominance decades ago. By eliminating the heavy licensing fees and royalties associated with commercial chips from dominant players like Intel, AMD, and Nvidia, companies can significantly reduce costs. Furthermore, the ability to reuse infrastructure and collaborate on shared designs fosters faster innovation. Perhaps most importantly for security, open-source designs offer greater transparency throughout the supply chain. With more eyes on the code and the silicon blueprints, vulnerabilities and defects can be detected and remediated far more quickly than in proprietary "black box" systems.