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.

中文翻译：

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面向无线智能终端的鲁棒隐蔽通信

第五代 (5G) 无线系统为改善现有互联网协议语音通信服务的用户体验提供了机会。为了降低5G数据泄露的安全风险，构建隐蔽通道是提供机密数据传输的另一种方法。由于5G的高传输速率，包间间隔变小且去随机化，导致隐蔽定时信道的编码阶段引入较大的调制误差。重排是数据通信中普遍存在的现象。在本文中，我们提出了一种重排隐蔽通道方法，称为混合可变长度数据包重排隐蔽定时通道（HVPR-CTC），它从公开流量中人工选择定界符数据包和标识（ID）数据包，根据生成的混合变长码字字典对相邻定界包之间的包发送顺序进行编码，通过重新排列ID包的发送顺序来嵌入密文。实验表明，HVPR-CTC方案能够有效地进行策略调整：其最小Location Square Deviation为0.832，最小Swap Deviation为139，最大吞吐量达到14.37 bps，最佳误码率为3.27%和9.70% -分别为信道噪声和高信道噪声通信条件。