I am quite sure that most of you are familiar with the term Steganography which is the art and science of hiding our data. But today we’ll look into a different kind of Steganography technique called Reverse Steganography which is based on TCP/IP protocol and various similar protocols that utilises retransmission mechanisms.

As we know that during a TCP/IP communication between two machines,the sender sends the data packets to the receiver and the receiver sends the acknowledgment of receiving the packets. If a packet is lost during the communication or the sender doesn’t receive the intended acknowledgment it sends the data packet again. The whole concept of  Retransmission Steganography is based on this approach. Here we don’t acknowledge a successfully received packet in order to intentionally invoke retransmission of that packet. The receiver intentionally signals that a loss has occurred. The sender then retransmits the packet but with some secret data inserted in it. That’s the basic idea behind Retransmission Steganography Technique.

For more detail on this very interesting topic you can check this link and download the complete paper to take a deeper look into this technique.Good bye.