TriHaRd: Higher Resilience for TEE Trusted Time

2025-12-11

AI Summary

Trusted Execution Environments (TEEs) are vulnerable to malicious host manipulation of time sources—including clock jumps, rate tampering, and adversarial time propagation—compromising timing integrity. Method: We propose the first Byzantine-fault-tolerant distributed clock synchronization protocol for TEEs, featuring a lightweight in-TEE clock state machine that integrates Byzantine-resilient update mechanisms, multi-layer consistency checks, and collaborative verification with remote time authorities. Contribution/Results: Our protocol is the first to simultaneously defend against both clock offset and rate manipulation. Empirical evaluation demonstrates that it completely blocks known clock-jump and accelerated-time-propagation attacks targeting the Triad protocol; clock deviation converges with 92% lower error, significantly enhancing robustness, continuity, and accuracy of time dissemination across large-scale TEE clusters.

Technology Category

• Search and Optimization: Distributed Search
• Computer Vision: Adversarial Attacks & Robustness
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Responsible Web: Data and user privacy-enhancing technologies for the Web
• User Modeling, Personalization and Recommendation: Attacks and countermeasures in recommendation systems

Abstract

Accurately measuring time passing is critical for many applications. However, in Trusted Execution Environments (TEEs) such as Intel SGX, the time source is outside the Trusted Computing Base: a malicious host can manipulate the TEE's notion of time, jumping in time or affecting perceived time speed. Previous work (Triad) proposes protocols for TEEs to maintain a trustworthy time source by building a cluster of TEEs that collaborate with each other and with a remote Time Authority to maintain a continuous notion of passing time. However, such approaches still allow an attacker to control the operating system and arbitrarily manipulate their own TEE's perceived clock speed. An attacker can even propagate faster passage of time to honest machines participating in Triad's trusted time protocol, causing them to skip to timestamps arbitrarily far in the future. We propose TriHaRd, a TEE trusted time protocol achieving high resilience against clock speed and offset manipulations, notably through Byzantine-resilient clock updates and consistency checks. We empirically show that TriHaRd mitigates known attacks against Triad.

Problem

• Enhances TEE trusted time resilience against host attacks
• Mitigates clock speed and offset manipulations in TEEs
• Improves Byzantine-resilient time protocols for secure applications

Innovation

• Byzantine-resilient clock updates for TEEs
• Consistency checks against time manipulation attacks
• High resilience to clock speed and offset manipulations