Research paper on covert channels

[matthijs () koot biz]

As part of our MSc study on System and Network Engineering at the University of Amsterdam, NL, Marc Smeets and I have 
done research on covert channels. 

Abstract:

"Covert channels have been topic of discussion within both academic and non-academic communities for more than two 
decades. Traditionally, research on this topic focussed on storage and timing channels within singular systems. As more 
systems became interconnected in the last decade, the scope expanded to network-based covert channels. Numerous designs 
and implementations of such covert channels have been suggested, altogether leaving the world with valuable pieces of 
knowledge scattered around the Internet. By aggregating the essentials and representing them in a structured format, we 
attempt to provide clarity on the current state of research. In addition, a (non-exhaustive) overview of contemporary 
trends in network-based covert channels is given, explaining common channels within IP, TCP, ICMP, HTTP and DNS. 
Lastly, several implementations were evaluated to gain insight in their efficiency and performance, and the influences 
to which they're prone. We conclude that they p
 ose a security issue that needs proper attention when defining and enforcing security policies, and expect more 
sophisticated covert channels to appear in the future."

The paper is available at the following URL:

http://www.os3.nl/~mrkoot/courses/RP1/researchreport_2006-02-15_final2.pdf

Feedback is more than welcome!

(I posted to bugtraq since the secpapers list appears rather dormant)