A digital watermark for vector-based fonts

In this paper we present a blind watermarking scheme for vector-based fonts. The scheme can be used for authenticating the copyright holder as well as for identifying customers of fonts. We slightly modify the symmetry between curve pairs to embed a binary message. The watermark is invisible and robust against conversion into other vector-based font formats. An implementation for TrueType-Fonts was evaluated by typeface designers. Based on the blind watermarking scheme we discuss an extension to a non-blind watermark, which is in addition robust against uniform scaling.