Image Content Authentication Using Number Theoretic Approaches

Abstract

Multimedia is anything and everything that we watch and listen in the form of text, image, audio or video. Today, it is a primary source of information and key component in communication, thanks to its huge expressive capability. Advancements in technology and the Internet has facilitated proliferation of the multimedia and along with it issues like data vulnerability and fraud. There is an inherent need for authentication mechanisms to ensure trust worthiness and integrity of digital media and ensure its security during storage and transmission. Watermarking is a common mechanism used for authentication of digital media. Improving the security aspect of an authentication system without compromise on quality and robustness of the media is a key research challenge. Security of a watermark based authentication scheme lies in the complexity and randomness involved in the watermark generation and embedding process. Any defensive scheme is incomplete without a secret key or random sequence to generate sufficient random noise to scramble or mask the watermark, sensitive information or the embedding pattern. This is to prevent unauthorized detection, reading, removal or tampering of the watermark by an adversary. Number theory based approaches have been used in literature for pseudorandom number generation but they involve the use of very large seeds with hundreds of digits and are computationally slow. They are seldom adopted due to the nature of complex computations involved. newline