Abstract: The end hopping and spreading technology is an active defense technology that pseudorandom changes the end information in the end to end data transmission and uses the end spreading sequence to realize high-speed synchronous authentication. In this paper, the end hopping and spreading technology is introduced into file covert transfer, the file covert transmission strategy under the end hopping and spreading network is studied, the multicast time correction scheme is proposed, and the synchronization problem in communication process is solved. Two kinds of file transfer schemes based on time transfer and transmission size transfer are proposed for the end hopping and spreading network, and the data migration is added into the file transfer process to realize the covert transmission and integrity transmission of files. A prototype system is designed and implemented for the file covert transfer of end hopping and spreading, and the usability and security are tested. The experimental results show that the file covert transfer strategy can effectively meet the requirements for the integrity and concealment of file transfer.

Key words: covert communication, end hopping and spreading, file transfer, multicast time correction, data migration