Image steganography can be seen as the modern version of the invisible ink, where applying lemon juice on a sheet of paper has been replaced by flipping a couple of bits in a digital image. In order to automatically detect hidden messages inside images, researchers have developed a specific field called steganalysis. BOSS (Break Our Steganography System) is being organized as the first scientific challenge on this topic in order to compare the efficiency of steganalysis methods. The organizing researchers include Tomas Filler from the University of Binghamton - USA, Tomas Pevny from the Technical University of Prague - Czech Republic, and Patrick Bas from the Centre National de la Recherche Scientifique in Lille – France.  Starting September 9th 2010, 1000 images will be available on the website of the challenge. The goal of the participants is to figure out which images contain a hidden message and which images do not. The challenge will end the 15th of December and the winner will be the competitor who will have submitted the most accurate prediction.  Please refer to the BOSS webpage for more details.