Which of the following tools is used to attack the Digital Watermarking? 

Answer options:

A. Steg-Only Attack
B. Active Attacks
C. 2Mosaic
D. Gifshuffle

looks like a real image with no watermark in it. This attack is successful, as it is impossible to read watermark in very small pieces. Answer: D is incorrect.

2Mosaic is a tool used for watermark breaking. It is an attack against a digital watermarking system. In this type of attack, an image is chopped into small pieces and then placed together. When this image is embedded into a web page, the web browser renders the small pieces into one image. This image Gifshuffle is used to hide message or information inside GIF images. It is done by shuffling the colormap. This tool also provides compression and encryption.