Confidential computing and TEE

In short: Confidential computing protects data while it is processed, by running the code in an isolated hardware environment (TEE) that even the machine’s operator cannot look into.

In more detail: Encryption protects data on disk and in the network. During computation, however, it sits in memory in plaintext. A TEE (“trusted execution environment”) closes this gap.

In Depth

• Principle: The CPU encrypts the memory of the protected area (enclave or encrypted VM) and releases it only to the matching code. Operating system, hypervisor and cloud provider see only ciphertext.
• Technology: Intel SGX and TDX, AMD SEV-SNP, ARM TrustZone and CCA, in phones the Secure Enclave.
• Attestation: The hardware proves cryptographically to third parties which code runs in which environment. Only then do users send secrets in.
• Use: Sensitive data in the cloud, joint analysis of data from several companies, private AI inference, key management.
• Limits: You must trust the chip vendor. Side-channel and other attacks on TEEs have occurred, and performance drops slightly.
• Alternatives: Homomorphic encryption (purely mathematical, but slow).

See also: virtualisation