Root of trust concentrated in a few hardware vendors

The root of trust is the certificate authorities of a small number of vendors (AMD, Intel and NVIDIA), which generate the keys and fuse them onto the chips. Gloria Z notes that whoever has access to a hardware key, or can certify one, can in principle produce valid reports for arbitrary measurements without the physical chip ¹¹. Attestable Audits notes that the approach holds only "as long as the vendor of the secure hardware is trusted" ⁸. A 2026 preprint reports that a host with root control and the ability to rewrite platform flash can downgrade an AMD EPYC Milan processor to legacy security-processor firmware and extract the hardware root seed from which SEV-SNP attestation keys are derived. The authors state that this lets them forge attestation reports for any firmware version ³⁷. AMD describes the firmware-loader flaw the attack starts from as a legacy attack mitigated in 2021 ³⁸.