Text Zero-Watermark Based on Chinese Edit Distance

In research of the copyright protection of digital text, according to the shortage of poor robustness and weakness of attack resistance for the existing text watermark, Chinese machine code and information gain strategy have been introduced into text zero-watermark scheme, which puts forward the text zero-watermark based on the Chinese Edit Distance, constructs the construction and detection process model, and designs the core algorithm. First, we introduce information gain to compute the weighting terms in paragraph to select the text feature. Then, we use Chinese machine code to express the text feature formally. Last, we compute the edit distance between the characteristic words in every paragraph and mark the commutation position to form an edit distance matrix to complete text zero-watermark construction. In detection stage, we analyze the edit distance and commutation position to reflect the distortion status. In order to validate effectiveness and feasibility of the scheme, simulation experiments are provided. The results indicated that the scheme has good robustness and strong ability against attack, especially, for the attack toward sentence type conversion and add & delete words, it has more obvious advantages.