Covert channel vulnerabilities in anonymity systems

Monday, 10 December 2007, 4:10 PM EST

The spread of wide-scale Internet surveillance has spurred interest in anonymity systems that protect users’ privacy by restricting unauthorised access to their identity. This requirement can be considered as a flow control policy in the well established field of multilevel secure systems. I apply previous research on covert channels (unintended means to communicate in violation of a security policy) to analyse several anonymity systems in an innovative way.

One application for anonymity systems is to prevent collusion in competitions. I show how covert channels may be exploited to violate these protections and construct defences against such attacks, drawing from previous covert channel research and collusion-resistant voting systems.

In the military context, for which multilevel secure systems were designed, covert channels are increasingly eliminated by physical separation of interconnected single-role computers. Prior work on the remaining network covert channels has been solely based on protocol specifications. I examine some protocol implementations and show how the use of several covert channels can be detected and how channels can be modified to resist detection.

At cl.cam.ac.uk

[ Read more ]




Spotlight

Internet of Things: Bracing for the data flood

Whether we think we should be connecting the IoT and our existing systems together or not, the basic imperative to extract business intelligence from the raw information will demand that the connection takes place.


Weekly newsletter

Reading our newsletter every Monday will keep you up-to-date with security news.
  



Daily digest

Receive a daily digest of the latest security news.
  
DON'T
MISS

Tue, Jul 28th
    COPYRIGHT 1998-2015 BY HELP NET SECURITY.   // READ OUR PRIVACY POLICY // ABOUT US // ADVERTISE //