The Research on Information Hiding Based on Command Sequence of FTP Protocol

Traditional covert channels study mainly focus on digital signature, operation system and multimedia technology. The covert channels in TCP/IP protocol suite have many advantages, such as they are harder to be detected and more robust. Two covert channels are discovered by using FTP protocol command sequence based on the study of FTP protocol. The principles of covert channels are analyzed. Three characters of covert channels, which are concealment, bandwidth and robustness, are studied. And the methods to construct covert channels are also applicable to other internet protocol.