Coverless Image Steganography Based on SIFT and BOF

In order to realize secret communication, conventional steganography techniques can embed the secret message into carrier images by modifying the content and structure of carrier images. Although steganography techniques provide us with some more secure communication, the modification traces will be detected through using these brand-new steganalysis tools. Thereby, in order to eliminate the influence of modification traces, we propose a novel coverless image steganography scheme based on scale invarient feature transform and bag of feature. Different from conventional steganography, images have already contained the concealing information, so we can transmit natural images, whose features are the same with the secret information, to receivers. Firstly, the robust feature hash sequences are constructed with our protocol of feature. Then, the secret message is converted into bitstreams. Finally, these images with the seceret information are chosen and sent to receivers through using inverted index. Throughout the process, original images are never modified in our scheme, so our method can resist the analysis of existing steganalysis tools. Numerical experiments also indicate that our scheme has a desirable robustness to the common image attacks.