tee
**Trusted Execution Environments (TEE)**
**What is a TEE?**
A secure area of a processor that runs code and stores data protected from the main operating system, providing hardware-based security guarantees.
**How TEEs Work**
```
[Normal World] [Secure Enclave]
| |
Application --(encrypted)--> Protected Code
| |
OS [Isolated Memory]
| |
Hypervisor [Hardware Protection]
```
**TEE Technologies**
| Technology | Provider | CPU |
|------------|----------|-----|
| SGX | Intel | Intel CPUs |
| TrustZone | ARM | ARM chips |
| SEV | AMD | AMD EPYC |
| CCA | ARM | ARMv9 |
| Keystone | RISC-V | RISC-V |
**Intel SGX Concepts**
| Concept | Description |
|---------|-------------|
| Enclave | Protected memory region |
| Attestation | Prove code is running in enclave |
| Sealing | Encrypt data to enclave identity |
| Ocall/Ecall | Communication into/out of enclave |
**Confidential Computing Use Cases**
```python
# Conceptual: Run ML inference in enclave
def secure_inference():
# Inside enclave
model = load_encrypted_model()
model.decrypt_with_enclave_key()
# Process encrypted input
encrypted_input = receive_from_client()
decrypted_input = decrypt_in_enclave(encrypted_input)
# Run inference
result = model.predict(decrypted_input)
# Re-encrypt result
return encrypt_for_client(result)
```
**Benefits**
| Benefit | Description |
|---------|-------------|
| Data confidentiality | Data protected in use |
| Code integrity | Tampering detected |
| Attestation | Verify what code is running |
| No trust in cloud | Cloud cant see data |
**Limitations**
| Limitation | Description |
|------------|-------------|
| Performance | Some overhead |
| Memory limits | Enclave memory constrained |
| Side channels | Vulnerable to some attacks |
| Complexity | Harder to develop |
**Cloud Confidential Computing**
| Cloud | Offering |
|-------|----------|
| Azure | Confidential VMs |
| GCP | Confidential Computing |
| AWS | Nitro Enclaves |
| IBM | Confidential Computing |
**ML in TEEs**
- Run inference on private data
- Protect model weights from cloud
- Multi-party computation
- Confidential training
**Best Practices**
- Use attestation to verify enclave
- Minimize enclave surface area
- Handle side-channel risks
- Test thoroughly before deployment