Moment invariants for digital image authentication and authorization

Now a day, multimedia security is an incredibly significant area of concern. The large diffusion of multimedia products distributed both through CD-ROMs (off-line) and through Internet (on-line) is raising many problems among the authors regarding preservation of their rights. It is very important to have ways and means to detect copyright violations and control access to digital media. In this paper we have given the idea of steganography, which hides watermarks into the information as digital stamps for authentication and authorization. The aim of this paper is to design a robust image-watermarking scheme, which can withstand with incidental and intentional attacks in the communication channel. The proposed scheme provides a robust solution integrating image moment normalization, feature dependent watermark and discrete wavelet transformation. Moment normalization is useful to recover the watermark even in case of geometrical attacks. The use of cryptographic keys allows additional security and tamper detection in case of any fraud or fabrication in the image. In this paper we propose for a technique which uses multi-energy bands of discrete wavelet transform for multiple and multipurpose watermarking scheme.