基于翻译的信息隐藏分析检测

Analysis and Detection of Translation-Based Steganography

基于翻译的信息隐藏(Translation-Based Steganography,TBS)是一类文本信息隐藏算法,它利用不同的翻译机对同一个句子翻译产生的结果一般不同这一特性,使用多台翻译机翻译同一段文本,最终译文的每个句子根据隐藏信息来选择不同翻译机的翻译结果以形成隐藏文本.这种方法基本保证了隐藏文本语法的正确性和语义的连贯性,传统的检测算法很难发现隐藏文本.本文研究发现,在知道TBS算法所使用的翻译机集合的条件下存在一种TBS检测算法,因此对TBS算法所使用的翻译机集合保密是TBS算法安全的关键.文章从理论上分析了检测算法的有效性,并给出了算法的过程和实验结果.另外,我们还给出了增强TBS安全性的方法.

Translation-Based Steganography（TBS） is a class of text steganography.When translating the same sentence from a natural language to another by different translators,there are normally different translation results.Making use of this property,TBS chooses from different translation results of a sentence according to secrete messages to generate stego-text.Because TBS basically preserves syntactic correctness and semantic coherence,it is comparatively difficulty for traditional detections to detect this method.Our research shows that there exists a detection method for TBS when we know the Machine Translation（MT） set that being used by TBS.So it is crucial important to keep a secret of the MT set.This paper theoretically analyzes the effective of our detection method and gives the detection process and experiment results.Additionally,we propose a method to improve the security of TBS.