Digital watermarking for textual data

Abstract

Methods and system for embedding digital watermark information into textual data arranged in a table of cells are provided. A first subset of cells are selected and for each primary cell key and cell partition number are determined. A portion of a digital watermark ID code is embedded at an embedding position determined based on the partition number. Methods and systems for extracting digital watermark information from the textual data are also provided. A cell is fetched from the table and the presence of portion of the digital watermark ID code is determined. A primary cell key and cell partition number are determined. A portion of the digital watermark ID code is extracted at the embedding position within the cell, the embedding position determined based on the cell partition number. The digital watermarking systems and methods provide tracking for unauthorized copying of the data while modifying only a subset of the data.

Dependencies are inferred from the claim text.