Updates and Asynchronous Communication in Trusted Computing Systems

Software-based usage controls typically are vulnerable to attacks. Trusted platform modules (TPMs) can enable much more robust controls. However, as conventionally understood, TPM-secured systems may not support software updates or asynchronous communication. We contribute techniques that overcome these limitations, enabling updates, secure transmission of usage-controlled files via email or removable disks, and secure use of such files on low-cost commercially available computers. We implemented the proposed scheme on Linux and report on its performance.