Network Steganography Based on PVD Idea

Network steganography based on the packet length, is a branch of network steganographic methods that transfers intended message by modifying the length of the packets in the network. In this paper, a new network steganographic method based on the packets length is presented using the idea of embedding the message in the lengths differences of the consecutive packet pairs. Modifying reference packets length is being done in a way that the receiver could entirely extract data by computing differences in the lengths of the consecutive packet pairs. The number of the embedded message bits in the length of the consecutive packet pairs is variable but the receiver could simply detect it. The tests of the proposed methods against existing attack have been done for network random traffic type and for different cases of distributing the message over the entire reference traffic. In all cases, the proposed method has greater resistance in comparison to the existing methods. In another words, by using this embedding method, the characteristics of the normal traffic are preserved, so that its generated traffic would be indiscernible from normal traffic.