What is remote attestation, and why is it the critical dependency for trusting a TEE?
Attestation is a cryptographically signed proof from the hardware that the enclave is genuine and running the exact expected code — without it, you can't trust that your data is really protected.
A TEE's promise ("your data is isolated") is only meaningful if you can verify that:
- You're really talking to a genuine, untampered enclave (not a fake or emulator).
- The enclave is running the expected, unmodified code.
Attestation provides that: the CPU produces a signed measurement (hash) of the enclave's contents, which a remote party checks against the hardware vendor's keys before sending any secrets.
The catch — it's a trust dependency: you must trust the hardware manufacturer (and its attestation service) and the integrity of the chip. If the silicon or its keys are compromised (as past SGX side-channel attacks showed), the guarantee weakens. Confidential computing moves trust from the cloud operator to the chip vendor — it doesn't eliminate trust.