Available steganograpic and steganalysis methods:

RS Analysis has been developed for detection of LSB embedding in randomly scattered pixels in BMP images. This embedding archetype has been adopted by most steganographic tools available on the Internet. Details of the algorithm can be found in

• J. Fridrich, M. Goljan, and R. Du, Reliable Detection of LSB Steganography in Grayscale and Color Images, Proc. of the ACM Workshop on Multimedia and Security, Ottawa, Canada, October 5, 2001, pp. 27-30. PDF,
• J. Fridrich, M. Goljan, and R. Du, Detecting LSB Steganography in Color and Gray-Scale Images, Magazine of IEEE Multimedia Special Issue on Security, October-November 2001, pp. 22-28. PDF,
• S. Dumitrescu, Xiaolin Wu, Zhe Wang, Detection of LSB Steganography via Sample Pair Analysis, 5th Information Hiding Workshop, Noordwijkerhout, The Netherlands, 7-9 October 2002.

Raw Quick Pairs Analysis is an older method for detection of random LSB embedding that may in some exceptional cases give better results than RS steganalysis (especially for small images with low number of unique colors). Description of this method can befound in this paper:

• J. Fridrich, Rui Du, and Long Meng, Steganalysis of LSB Encoding in Color Images, ICME 2000, New York City, July 31-August 2, New York, USA. PostScript, MS Word 97.

Palette Quick Pairs Analysis should be applied only to GIF images and it can detect messages embedded in GIF images using S-Tools or any other steganographic algorithm that preprocesses the palette by creating clusters of close colors that differ in their LSBs only. Here is the document that explains the algorithm.

Pairs Analysis has been developed for detection of EzStego with random scatter. The detection method can be applied to any other steganographic algorithm that embeds message bits into LSBs of indices to a pre-sorted palette (this would require modification of the code). For more detailed description of this method, see:

• J. Fridrich, M. Goljan and D. Soukal, Higher-Order Statistical Steganalysis of Palette Images, submitted to EI SPIE Santa Clara, CA, Jan 2003.
• J. Fridrich, M. Goljan, D. Hogea, and D. Soukal, Quantitative Steganalysis of Digital Images: Estimating the Secret Message Length, submitted to the ACM Multimedia Systems Journal, Special issue on Multimedia Security.

ISP detects messages embedded in JPEG files using Invisible Secrets Pro. Here is the document that explains the algorithm.

JSteg detects messages embedded in JPEG files using J-Steg with sequential embedding. Here is the document detailing the algorithm.

F5 detects messages embedded in JPEG files using the F5 algorithm (currently without double compression correction). More details can be found in:

• J. Fridrich, M. Goljan, and D. Hogea, Steganalysis of JPEG Images: Breaking the F5 Algorithm, 5th Information Hiding Workshop, Noordwijkerhout, The Netherlands, 7–9 October 2002,
• J. Fridrich, M. Goljan, and D. Hogea, New Methodology for Breaking Steganographic Techniques for JPEGs, submitted to EI SPIE Santa Clara, CA, Jan 2003,
• J. Fridrich, M. Goljan, D. Hogea, and D. Soukal, Quantitative Steganalysis of Digital Images: Estimating the Secret Message Length, submitted to the ACM Multimedia Systems Journal, Special issue on Multimedia Security.

For more papers on steganalysis and steganography produced by DDE members, check the publications page.