A Noval Security Mechanism for Image Authentication and Copyright Protection

Encryption and watermarking are two primary and complementary technologies for protecting multimedia content. In this paper, we present a hybrid image protection scheme to establish a robust content-based authentication by using novel cryptosystem based on matrix transformation for generation of encryption key and copyright protection by using SVD based watermarking system. This paper suggests efficient method for encryption of image by self-invertible matrix with Hill Cipher algorithm. The Hill cipher algorithm is a symmetric cryptosystem for data encryption but cannot encrypt images. The novel cryptosystem uses randomly generated self-invertible matrix as an encryption key for each block encryption of an image and finding inverse of the matrix while decryption. This method having less computational complexity, because the inverse of the matrix is not required for decryption. For watermarking, we use SVD concept to provide a removable watermarking scheme for content based watermarking. The proposed scheme modifies the embedding strategy of SVD scheme. The proposed scheme yields higher security with superior encryption and robust to common image processing distortions. Experimental results show the effectiveness of the proposed hybrid scheme. KeywordsCryptosystem, Hill cipher, Image encryption, Self-invertible matrix, Watermarking, Singular value decomposition.