Data-in-Use Protection

The foundational property that creates a hardware-enforced boundary between protected workloads and the host environment. Unlike software-based isolation, this boundary is enforced at the silicon level.

• Enclave architecture: Code and data reside in a private memory region inaccessible to the OS, hypervisor, or DMA attacks
• Protection scope: Guards against privileged users, malicious insiders, and compromised infrastructure
• Implementation: Achieved through technologies like Intel SGX, AMD SEV, and AWS Nitro Enclaves

This isolation ensures that even a fully compromised operating system cannot read the plaintext data being processed.

A mechanism that enables verifiable trust between the protected environment and remote parties before any secrets are released. Attestation proves the identity and integrity of the execution environment.

• Measurement: The TEE generates a cryptographic hash of its initial state, including code and configuration
• Verification: A signed attestation report is validated against the manufacturer's certificate chain
• Freshness: Nonces prevent replay attacks and ensure the attestation is current

This property transforms an untrusted cloud host into a verifiably trustworthy compute node, enabling secure multi-party computation scenarios.

Transparent, hardware-level encryption that protects data as it moves between the processor cache and main memory. This defense operates at line speed with negligible performance impact.

• Encryption boundary: Data is encrypted before leaving the CPU package and decrypted only inside the processor die
• Key management: Encryption keys are generated by the hardware root of trust and never exposed to software
• Protection target: Defeats cold boot attacks, DRAM probing, and physical memory interception

Memory encryption closes the gap left by disk and network encryption, ensuring data remains protected during the critical moment of active processing.

A TEE-specific cryptographic operation that binds encrypted data to a specific enclave identity, ensuring it can only be decrypted by the exact same enclave on the exact same hardware.

• Identity binding: Sealed data is tied to the enclave's measurement and the platform's unique key hierarchy
• Policy enforcement: Decryption policies can include version constraints and debug state restrictions
• Use case: Protects model weights and inference results when stored outside the TEE for later processing

Sealing provides stateful confidentiality, allowing sensitive workloads to persist data securely across restarts without exposing secrets to the host environment.

The principle of reducing the attack surface to the smallest possible set of components that must be trusted. A smaller TCB means fewer potential vulnerabilities and easier formal verification.

• Excluded components: The host OS, hypervisor, device drivers, and management tools are removed from the trust boundary
• Included components: Only the application code, the TEE firmware, and the processor hardware remain trusted
• Verification: A minimal TCB enables rigorous security audits and mathematical proofs of correctness

This property is the architectural foundation of confidential computing, ensuring that security guarantees do not depend on the integrity of a sprawling software stack.