University of Salamanca
In this paper, the authors, starting from the classification of information hiding adapted from Bauer, analyze four new methods for embedding data into the OOXML file format. These methods can be extremely useful when using MS-Office documents for steganographic purposes. The authors, analyzing a scenario composed of about 50.000 MS-Office files, highlight how the proposed methods are really helpful in real applications. An evaluation of the limits of the proposed methods is carried out by comparing them against the tool introduced by Microsoft to sanitize MS-Office files. The methods presented can be combined in order to extend the amount of data to be hidden in a single cover file.