Deluding image recognition in sift-based cbir systems

Content-Based Image Retrieval Systems used in forensics related contexts require very good image recognition capabilities. Therefore they often use the SIFT local-feature description scheme as its robustness against a large spectrum of image distortions has been assessed. In contrast, the security of SIFT is still largely unexplored. We show in this paper that it is possible to conceal images from the SIFT-based recognition process by designing very SIFT-specific attacks. The attacks that are successful in deluding the system remove keypoints and simultaneously forge new keypoints in the images to be concealed. This paper details several strategies enforcing image concealment. A copy-detection oriented experimental study using a database of 100,000 real images together with a state-of-art image search system shows these strategies are effective. This is a very serious threat against systems, endangering forensics investigations.