Undercover Communication Using Image and Text as Disguise and Countermeasures

A brief survey of some representative techniques of steganography and steganalysis is presented. Various methods developed in the authors’ laboratory are introduced, including symmetric LSB embedding, secure steganography in JPEG, palette, and uncompressed color images, histogram-based analysis and least histogram abnormality steganography, multiple-base notational system based embedding, stego-encoding integrated with error correction, etc. Some of the proposed approaches provide overall improvement, while others offer alternatives to existing techniques with advantage in certain aspects. Data hiding in text using the typesetting tool TeX is also introduced, with a brief description of a recently developed technique. Current research topics and the future plan are outlined. The discussion is focused mainly on steganography/steganalysis in still images.