Scalable Web Content Attestations

Open Access
Moyer, Thomas Michael
Graduate Program:
Computer Science and Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
April 08, 2009
Committee Members:
  • Patrick Drew Mcdaniel, Thesis Advisor
  • integrity measurement
  • trusted computing
  • attestations
  • security
The web is a primary means of information sharing for most organizations and people. Currently, a recipient of web content knows nothing about the environment in which that information was generated other than the specific server from whence it came (and even that information can be unreliable). In this paper, we develop and evaluate the Spork system that uses the Trusted Platform Module (TPM) to tie the web server integrity state to the web content delivered to browsers, thus allowing a client to verify that the origin of the content was functioning properly when the received content was generated and/or delivered. We discuss the design and implementation of the Spork service and its browser-side Firefox validation extension. In particular, we explore the challenges and solutions of scaling the delivery of mixed static and dynamic content using exceptionally slow TPM hardware. We perform an in-depth empirical analysis of the Spork system within Apache web servers. This analysis shows Spork can deliver almost 8,000 static or 7000 dynamic integrity-measured web objects per-second. More broadly, we identify how TPM-based content web services can scale with manageable overheads and deliver integrity-measured content.