Image Encryption for Secure Data Transfer and Image based Cryptography

With rapid progress in internet and digital imaging technology there are more and more ways to easily create, publish and distributed images. A major issue for computer networks is to prevent important information from being disclosed to illegal users. Valuable multimedia content such as digital images, however, is vulnerable to unauthorized access while in storage and during transmission over a network. Resent advances in visual cryptography, including probabilistic schemes and colored image sharing techniques were introduced. Visual cryptography is a method for protecting image based secrets that has a computation-free decoding process. This paper focuses on image feature protection techniques which enable similarity comparison among protected features. Experimental results shows that secure image retrieval can achieve comparable retrieval performance to conventional image retrieval techniques without revealing information about image content. Thus the image retrieval process becomes simple. MATLAB based coding manage the query phase of the system. Based on the simulation results, the proposed system not only shows the efficiency in hiding the attributes but also provides other advantages such as: (1) fast transmission of the retrieval image to the receiver, (2) searching made easy. This work enriches the area of secure information retrieval and can find applications in secure online services for images and videos. Keywords—Cryptography, secure image retrieval, visual cryptography, content based image retrieval, feature protection.