Intel TDX

Intel Trust Domain Extensions (TDX) was launched in 2023 as part of the 4th generation Xeon server processor platform. Like AMD SEV and Arm CCA, Intel TDX implements the confidential VM (CVM) concept. In particular, Intel TDX shares many similarities with the slightly older AMD SEV. Possibly the most notable important difference is that TDX provides a set of four runtime-measurement registers (RTMRs), which can be "extended" at runtime and are included in remote-attestation statements. With the RTMRs, it becomes possible to reflect a system's state even beyond its initial state. In the case of AMD SEV, this is also possible, but, due to the lack of hardware-backed RTMRs, requires more effort on the software side.