A novel robust text watermarking for word document

In this paper, a novel method of robust watermarking for word documents for protecting copyright and controlling dissemination is proposed. A word document consists of lots of objects and word objects are arranged in a hierarchical order. Every object has its own properties and functions. Some of the properties are special. They can´t be modified via the interface of word application but via programming only and their change will not cause any differences on the page. These special properties are suitable for hiding information. Watermarking which includes both the author and the legal user´s information is embedded in these special attributes of Word objects circularly after encryption, grouping and packing into the message. As the experimental results shown, this watermarking scheme performances excellent on robustness. After all kinds of attacks, including adjusting the features, deletion, insertion and replacement, and even massive attack, the watermarking can still be extracted from word document. It has a promising prospect of wide use fields of the copyright protection and text delivery on the internet and it applies to both English and Chinese language.