Securing Web Servers against Insider Attack

Too often, “security of Web transactions” reduces to “encryption of the channel”—and neglects to address what happens at the server on the other end. This oversight forces clients to trust the good intentions and competence of the server operator—but gives clients no basis for that trust. Furthermore, despite academic and industrial research in secure coprocessing, many in the computer science community still regard “secure hardware” as a synonym for “cryptographic accelerator.’ This oversight neglects the real potential of COTS secure coprocessing technology to establish trusted islands of computation in hostile environments—such as at web servers with risk of insider attack. In this paper, we apply secure coprocessing and cryptography to solve this real problem in Web technology. • We present a vision: using secure coprocessors to establish trusted co-servers at Web servers and moving sensitive computations inside these co-servers. • We present a prototype implementation of this vision that scales to realistic workloads. • Finally, we validate this approach by building a simple E-voting application on top of our prototype. From our experience, we conclude that this approach provides a practical and effective way to enhance the security of Web servers against insider attack. ∗This work was supported in part by by the U.S. Department of Justice, contract 2000-DT-CX-K001, and by Internet2/AT&T. However, the views and conclusions do not necessarily represent those of the sponsors.