Towards Designing a Stealthy Communication Channel for Hidden Information
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.