Color Watermarking Techniques for Text-based Media

The main focus in this thesis is text-based watermarking: that means embedding a secter payload of bits into a text, while keeping the text as unaltered as possible to make it harder to identifiy that a watermark happened at all. Using two Google Workplace add-ons we explore the efficacy, the ease of use and the portability of three structural watermarking techniques: Homoglyph-based watermarking, Space coloring-based watermarking and Grayscale based Watermarking. The latter two are techniques developed specifically for this thesis. Another important focus is the use of the Digital Object Identifer system as another level of protection for a document, using its metadata system like one would a Zero-watermarking technique.