Covert Channels in IPv6

Abstract

Covert channels are communication mechanisms that were never intended nor designed to carry information. As
such, they are often able to act “below" the notice of mechanisms designed to enforce security policies. Therefore, using
covert channels it might be possible to establish a covert communication that escapes notice of the enforcement mechanism
in place. Any covertchannel present in digital communications offers a possibility of achieving a secret, and therefore
unmonitored, communication. One of the most ubiquitous protocols in deployment is the Internet Protocol version 4 (IPv4).
Its universal presence and range make it an ideal candidate for covert channel investigation.This imminent exhaustion of
IPv4 address space will soon force a mass migration towards Internet Protocol version 6 (IPv6) expressly designed as its
successor. While the protocol itself is already over a decade old, its adoption is still in its infancy.An active warden is there
so that it can observe and modify network traffic in its area of responsibility. And active wardens performs the task to
prevent and disrupt covert channel communication by modifying the content of network traffic. As much as possible an active
warden should maintain the syntactic and semantic integrity of the modified traffic to avoid breaking the cover
communication.