Steganography in TCP/IP-Based Communication

Steganography is defined as the art and science of hiding information. The process is that hiding message in an appropriate carrier, and then sending the carrier to a receiver. Everyone except the receiver will not know it contains a hidden message. The paper presents a novel method for hiding message imperceptibly between nodes over Internet. This method embeds information into certain field of TCP/IP packet header. The changed packet will be analyzed by routers or servers as a normal one. According to the analysis on the TCP/IP protocols, message can be embedded into IP header's Identification, Flags, TCP header's Sequence-Number and Acknowledgment-Number fields. We discussed and compared each scenario in applications. At last, an application of this scheme in Fuel Cell Remote Monitoring System is given.