一种脆弱型数字水印技术研究与应用

An Application and Research of Fragile Text Watermarking

该文提出了字移编码和CRC校验技术的文本内容认证的脆弱型文本数字水印方案。通过使文本行内字符发生平移,即利用字间距的变化嵌入需要的水印信息。采用这种编码,首先是利用循环冗余检测技术(CRC)来求得该字符串的特征,然后是利用相邻字符之间的距离可以各不相同来得以实现。在水印检测时,通过重新计算CRC的余式,可以检测到文本是否遭受篡改。通过进一步的研究还可以发现,该方案不但可以以很高的精度检测到文本发生的篡改并能进行高精确度的定位,而且该方案还能将篡改进行分类:增加、删除和修改。

It is proposed a fragile text watermarking scheme for text content identification based on words movement coding and CR, C techniques in this paper. The watermark required is embedded into the target documents in way of moving the words within a line, which is used by changing the distances of difference words. It is a tvechnique implemented firstly by obtaining the characteristics of a string with CR, C techniques, and then by embedding the characteristics in a mean of coding into the different distances among variant words of the documents, The documents can be detected for tamper by recalculating the residue of CRC while check the watermark of document, With further research, the solution proposed can be capable of either detecting and locating tamper very precisely and exactly, or classifying the tamper in terms of insert, deletion, or update.