TPMSpy: Validation of Measured Boot Systems by Low-Level Tracing of TPM Usage
Researchers present TPMSpy, a platform-agnostic method validating TPM Measured Boot via low-level tracing, finding inconsistent Linux systemd measurements that break remote attestation and LUKS decryption.
An arXiv paper (2609.05011) introduces TPMSpy, a method that analyzes virtualized system–TPM interactions to independently reconstruct and validate TPM Event Logs without relying on the quoting mechanism, applicable to open and closed systems and demonstrated on Linux and Windows. A longitudinal analysis of Linux systems running systemd versions 245–258 (2020–2025) found wide divergence in Measured Boot usage, undocumented behavioral changes, and no common usage pattern. The authors report inconsistent measurement of user-space systemd services, which prevents reliable remote attestation and LUKS disk decryption on affected systems.
- Proposes platform-agnostic TPM usage tracing independent of the quoting mechanism
- Validated on both Linux and Windows, including closed implementations
- Longitudinal study of systemd 245–258 shows no single Measured Boot usage pattern
- Inconsistent user-space service measurements undermine remote attestation and LUKS decryption
- Identifies undocumented behavioral changes across systemd releases
Full article181 words · extracted from arxiv.org · click to collapse
Measured Boot extends trust in a booted system by recording cryptographic measurements of executed software and system state into a Trusted Platform Module (TPM), enabling subsequent verification through remote attestation. Although this mechanism is increasingly deployed in contemporary operating systems, its practical security depends on whether implementations measure the expected components under the expected conditions, yet this is not checked systematically. We propose a platform-agnostic method for analysing low-level TPM usage at the level of virtualized system--TPM interactions. It enables independent reconstruction and validation of the TPM Event Log without relying on the quoting mechanism itself. Because it does not depend on implementation details, it is applicable to both open and closed systems. We demonstrate the method on both Linux and Windows and conduct a systematic longitudinal analysis of Linux systems with systemd versions 245--258 (2020--2025), examining how Measured Boot usage evolved and observing wide divergence. No single usage pattern emerged amongst systems, warranting customized analysis. The analysis identifies undocumented behavioural changes, reveals inconsistent measurements of user-space systemd services, which prevent reliable remote attestation and LUKS disk decryption on such systems.
Text extracted automatically; images, tables and formatting may be missing. Original: https://arxiv.org/abs/2609.05011