Analysis and detection of translation-based steganography

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.