Date: October 3, 2025
Title: Securing Systems Foundations: The Design and Verification of a Virtual Firmware Monitor
Speaker: Charly Castes
Abstract: To accommodate ever-increasing multi-tenancy and security constraints, computer systems have evolved toward greater isolation between software components, from early time-sharing systems to virtualization and the emergence of confidential computing. Yet, even today, firmware remains all-powerful and completely unchecked. By executing with the highest privilege on the CPU, firmware can bypass hypervisor and confidential computing isolation, breaking any existing security guarantees in case of a compromise.
In this talk, we will explore how to secure the highest privilege level of the CPU, where the firmware runs. We will present the design, implementation, and verification of Miralis, a new kind of system we call a Virtual Firmware Monitor. We will explain how Miralis can safely and efficiently de-privilege unmodified vendor firmware on RISC-V platforms by revisiting classic virtualization ideas. Finally, we will explain how we verified core Miralis subsystems, from virtualization logic to assembly, by leveraging existing exhaustive ISA specifications.
Bio: Charly Castes is a final-year PhD candidate at EPFL in the Data Center Systems Laboratory. His research focuses on building secure systems foundations, with an emphasis on virtualization, confidential computing, and low-level system security. He is currently a visiting PhD student in the Software Systems Laboratory at Columbia University, was a visiting researcher in the Systems Research group at Google, and is a graduate of École Polytechnique.