Abstract: Concerning the problem in concealment performance and embedding capacity of the existing information hiding algorithm based on BitTorrent (BT) protocol messages, a new information hiding method based on Have message queues was proposed. Firstly, the capacity analysis module was set to judge whether the embedding capacity was beyond the limit of hiding capacity before embedding. Secondly, the improved parity mapping information coding method was used when the secret information was embedded into the sort of Have queues. Finally, the cyclical redundancy check method was introduced to verify whether the secret information was transmitted correctly when extracting. The experimental results show that, compared with the original parity mapping information coding method, the proposed method is able to increase the embedding capacity and improve the hiding performance of covert channel for its little influence on the statistical characteristics of Have queues.

Key words: information hiding technology, information hiding carrier, information coding method, covert communication, data verification

摘要： 针对以比特流（BitTorrent）协议消息为载体的信息隐藏算法在隐蔽性和嵌入容量上所存在的问题，提出一种以Have消息序列为载体的信息隐藏方法。首先，在秘密信息嵌入前设置容量分析模块，判断信息嵌入量是否超出信息隐藏容量上限；其次，在信息嵌入时使用改进的奇偶映射信息编码方式，将秘密信息嵌入到Have消息的排序中；最后，在信息提取时引入循环冗余校验（CRC）方法，验证秘密信息是否传输正确。实验结果表明，相比原有的奇偶映射编码方式，所提方法的嵌入容量明显提高，且通过对Have序列统计特性的分析，所提方法对Have序列统计特性的影响较小，隐蔽性较强。

关键词: 信息隐藏技术, 信息隐藏载体, 信息编码方式, 隐蔽通信, 数据校验