Date Added: May 2011
Data hiding is where the ends communicating are allowed to exchange messages abiding the security policy of the system. It transfers arbitrary bytes between two points in a fashion that would appear too legitimate to scrutinize. Protocol Steganography transmits the messages over covert channels within network traffic packets. The most effective covert channel occurs in a data stream that looks like a non-covert network traffic with a credible purpose. The paper proposes a new approach working on the assumption that a packet might be dropped at any moment by any intermediate node for many a reason. The need for retransmission for the dropped packet may convey the covert message to the other end of the covert channel.