Enclave Exposure
The Crisis in Confidential Computing doc_id: AVT-TEC-2025-002 date: Q4 2025 classification: PUBLIC author: Alpha Vector Advanced Projects status: VALIDATED
Executive Summary
The Promise: Trusted Execution Environments (TEEs) promise to protect "data-in-use" through hardware-enforced isolation.
The Failure: Sophisticated side-channel attacks have demonstrated that TEE isolation is probabilistic, not absolute—undermining the foundational security assumption of modern confidential computing.
Strategic Assessment: This creates existential questions for compliance regimes that assume TEE security (GDPR, HIPAA, PCI-DSS).
1. The TEE Security Model and Its Failure Modes
1.1 Architectural Overview
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Intel SGX: Enclave Memory, Encrypted Pages (MEE), Remote Attestation.
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AMD SEV-SNP: VM Attestation, Memory Encryption, Integrity Protection.
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Security Promise: "Even if OS, hypervisor, or physical server operator is malicious, data inside TEE remains confidential."
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Reality: TEE provides meaningful security against most attackers most of the time, but not against sophisticated side-channel attacks.
1.2 Side-Channel Attack Taxonomy
| Channel | Information Leaked | Attack Cost | Expertise Required | Status |
|---|---|---|---|---|
| Timing | Execution duration | $0 | Low | Widely exploited |
| Cache | Memory access patterns | $0 | Medium | Automated tools |
| Power | Cryptographic operations | $10K | Medium | Commercialized |
| EM Radiation | Computational activity | $50K | High | Practical |
| Memory Bus | Encrypted memory patterns | $500 | Medium | "Wiretap" (2024) |
| RAPL | Power consumption traces | $0 | Low | "PLATYPUS" (2024) |
Critical Insight: Most powerful attacks cost <$500 and require only moderate expertise.
2. Deep Dive: Major TEE Vulnerabilities
2.1 Battering RAM (Intel SGX) - March 2024
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Target: Intel SGX latest generation.
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Method: Rowhammer variant exploiting SGX page fault handling.
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Result: Complete extraction of attestation private key.
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Impact: Attacker can forge attestation reports, impersonating any enclave.
2.2 Wiretap (AMD SEV-SNP) - June 2024
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Target: AMD SEV-SNP (all generations).
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Method: Memory bus pattern analysis.
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Result: 96% plaintext recovery rate from encrypted VMs.
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Vulnerability: Encryption is CTR mode (counter mode). Same plaintext at same address = Same ciphertext.
2.3 Financial Services Threat Model
Scenario: Global investment bank deploying proprietary trading algorithms in Confidential VMs.
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Risk: Trading strategy extraction via side-channel.
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T+30 Days: Forensic investigation discovers unauthorized VM co-location.
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T+90 Days: Potential extraction of trading logic.
3. The Multi-Tenancy Catastrophe
3.1 Shared Hardware Attack Surface
Cloud Multi-Tenancy Reality: * Physical Server: 64 cores, shared L3 Cache, Memory Controller, Memory Bus.
- Key Insight: Each shared resource is an attack vector.
3.2 The Shared Responsibility Breakdown
| Attack Surface | Cloud Provider Responsibility | Customer Responsibility |
|---|---|---|
| Software vulnerabilities | ❌ No | ✅ Yes (patch guest OS) |
| Side-channel attacks | ⚠️ DISPUTED | ⚠️ DISPUTED |
| Physical access | ✅ Yes | ❌ No |
| Multi-tenant co-location | ⚠️ DISPUTED | ⚠️ DISPUTED |
4. Compliance Implications
4.1 GDPR - Personal Data in TEEs
Question: Does TEE satisfy "appropriate" security if side-channels can leak data? ICO Guidance: Organizations must conduct risk assessment of side-channel attacks and consider dedicated hardware for high-risk processing.
4.2 HIPAA - Protected Health Information (PHI)
Question: Does TEE satisfy HIPAA's "encryption" requirement if plaintext is leaked?
5. Technical Countermeasures
5.1 Hardware-Level Defenses
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Constant-Time Crypto: Eliminates timing side-channels.
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Cache Partitioning: Intel CAT / AMD CCIX.
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Authenticated Encryption: Moving from AES-CTR (vulnerable) to AES-GCM (secure).
5.2 Operational Mitigations
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Dedicated Hardware: Rent entire physical server ($4.08/hour vs $0.17/hour). 438:1 ROI for high-value workloads.
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Temporal Isolation: Run sensitive workloads only during exclusive time windows.
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Zero-Knowledge Computation: Proof of computation without exposing data.
6. Conclusion
The era of assuming TEE security is over. Side-channel attacks have transformed confidential computing from a binary security guarantee to a probabilistic risk calculation.
Strategic Mandate: Organizations must assess side-channel threats, mitigate with dedicated hardware, and monitor for anomalies.