Towards robust and stealthy communication for wireless intelligent terminals

Fifth-generation (5G) wireless systems provide an opportunity for improving the existing Voice over Internet Protocol communication service's user experience. To mitigate the security risk of 5G data leakage, building covert channel is an alternative approach of providing confidential data transmission. Due to the high transmission rate of 5G, the interpacket intervals become small and derandomized, this caused the encoding phase of the covert timing channel imports relatively large modulation errors. rearranging is a widespread phenomenon that is occurred over the data communications. In this paper, we propose a rearrangement covert channel approach named Hybrid Variable-length Packet Rearrangement Covert Timing Channel (HVPR-CTC), which artificially chooses the delimiter packets and identification (ID) packets from the overt traffics, and encodes the packet sending order between adjacent delimiter packets according to a generated hybrid variable-length codeword dictionary, and embeds the secret message by rearranging the sending order of the ID packets. The experiments demonstrate that the HVPR-CTC scheme can effectively perform strategy adjustment: its minimum Location Square Deviation is 0.832 and minimum Swap Deviation is 139. the maximum throughput reaches 14.37 bps, and the optimal Bit Error Rate is 3.27% and 9.70% for low-channel noise and high-channel noise communication conditions, respectively.