SecTPM

More than 100 IT companies, including HP, Intel, and Siemens, have joined forces in the Trusted Computing Group to jointly develop a hardware-based security mechanism. A key component of this protection mechanism is the Trusted Platform Module (TPM), a chip for PCs, laptops, PDAs, or cell phones that, in the future, will be able to record the device’s state (configuration, operating system, loaded software, etc.) and can unequivocally verify it using a digital signature (attestation). In addition, data can be tied to a computer or network using TPM-specific keys, which enables companies, for example, to better protect their trade secrets. On behalf of the Federal Office for Information Security (BSI), Fraunhofer SIT presented the results of a previously conducted security analysis of the TPM to the relevant TCG working groups and brought about changes to the current TPM specification. Another project goal was to contribute to the specification of the next TPM generation - which is currently under development - at an early stage in order to avoid vulnerabilities before they arise.

What is a TPM?

The Trusted Platform Module (TPM) features a cryptographic coprocessor, can calculate hash values, and generate random numbers and cryptographic keys. Part of the TPM is the Platform Configuration Register, which can be used, for example, to verify the configuration of a computer’s currently active operating system. Using this data, companies can, for example, restrict access to their local computer network so that only computers with the correct configuration and unmodified software are granted access. This would also make it much easier to prevent the spread of viruses and worms.

Improvements to the TPM

Based on the security analysis conducted in the predecessor project, improvement proposals were submitted to the TPM working group and are incorporated into the current Revision 103 of the TPM specification. Bugs have been fixed, and vulnerabilities that cannot be eliminated in this specification for compatibility reasons are highlighted.

In addition, the specification contains guidance on how to avoid these vulnerabilities. At the same time, the analysis results were taken into account in the work on the specification for the next TPM generation. Here, security-related vulnerabilities were addressed, among other things, by using a fundamentally different data structure. Initial analyses of the still-unfinalized specification were conducted, and new mechanisms were tested and analyzed.

Currently, researchers in the SMV division are working on an analysis of the now more advanced specification for the next generation of TPMs. To this end, the scenarios used in the first TPM analysis are being refined, new command sequences are being created based on the new specification, and these are being analyzed using the formal methods developed in SMV.

The following website provides an overview of the various activities in the field of Trusted Computing: Trusted Computing for Embedded Devices