Hardware Memory Encryption Architectures

Intel, AMD, ARM, and Amazon Web Services (AWS) provide different architectures to support confidential computing.

Intel has two technologies that support confidential computing. Software Guard Extensions (SGX), introduced in 2015 in the Skylake processor, provide new CPU instructions that permit applications to set up “enclaves,” or sections of memory that are always encrypted. To use SGX, developers must modify applications. Microsoft partners provide application support. However, the SGX instruction set has been deprecated in Intel Core (consumer) processors and going forward will be supported only on server platforms (Xeon).

Intel’s Total Memory Encryption (TME), introduced in 2021 with its Ice Lake (Xeon3) processor, allows the encryption of the entire address space of a physical machine or VM. As with SGX, contents are decrypted only when read by the CPU (and re-encrypted on write). Keys are generated at boot time from a random number and never leave the CPU. However, decryption adds processing overhead, which can be significant.