Our text watermarking app is based on homoglyph characters substitution for latin symbols. The proposed method is able to efficiently embed a password based watermark in short texts by strictly preserving the content. In particular, it uses alternative Unicode symbols to ensure visual indistinguishability and length preservation, namely content-preservation.
This fine-grain version of our text watermarking method is able to embed the watermark in all portions of the original text. In order to be able to verify a watermarked portion, as an additional layer of security, the original full text is also needed along with a long enough text portion. Minimal length requirement of portions is on average 100 characters, but it may vary depending on the characters in the portions.
S. G. Rizzo, F. Bertini and D. Montesi, Content-preserving Text Watermarking through Unicode Homoglyph Substitution. IDEAS 2016