Date Added: May 2011
Covert channel is secret communication path, which existence is not expected in original system of design. It allows different users access to the same information, at the same time, but from different points-of-view. It is being more and more studying due to the grooming of internet. Always high-bandwidth network covert channel pose the significant risk of detection over network. Although the existing technique utilized the reserved bits of header, timestamp, initial sequence number, packet length etc., for network covert channel, to some extend these have good temper resistance. But when increase their covert data capacity they become to fail to persist their original characteristics and vulnerable to network traffic detector. The authors are motivated to design to achieve a high bandwidth covert channel in network protocols.