Design and implementation of a TCG-based integrity measurement architecture

TLDR

Linux systems measure all executable content before execution, protecting the measurements with a TPM per TCG standards. The authors design and implement a secure Linux integrity measurement system that extends TCG trust concepts to dynamic executable content from BIOS to application layer. The system uses a TPM‑based trust measurement architecture applied to a web server, detecting rootkits and demonstrating practicality in measurement count and performance. The architecture achieves Microsoft NGSCB‑like guarantees on current hardware without new CPU modes, and successfully detects rootkits in a web server with acceptable measurement overhead.

Abstract

We present the design and implementation of a secure integrity measurement system for Linux. All executable content that is loaded onto the Linux system is measured before execution and these measurements are protected by the Trusted Platform Module (TPM) that is part of the Trusted Computing Group (TCG) standards. Our system is the first to extend the TCG trust measurement concepts to dynamic executable content from the BIOS all the way up into the application layer. In effect, we show that many of the Microsoft NGSCB guarantees can be obtained on today's hardware and today's software and that these guarantees do not require a new CPU mode or operating system but merely depend on the availability of an independent trusted entity, a TPM for example. We apply our trust measurement architecture to a web server application where we show how our system can detect undesirable invocations, such as rootkit programs, and that our measurement architecture is practical in terms of the number of measurements taken and the performance impact of making them.