A Robust and Secure Watermarking Scheme with Chinese Remainder Theorem

With the rapid growth of e-commerce, consumers getting used to buy goods from e-trading websites, and buying digital media such as music, images, and videos directly online become more and more popular. To protect the digital products, digital watermarking is a commonly adopted approach. According to some relative researches, general watermarking schemes are not robust enough while undergoing the geometric attacks. Facing this challenge, the well-performed moment-based watermarking techniques are utilized to against these attacks. Moreover, in our commerce model, content owners sell or delegate their products to e-commerce service providers (or reselling agents) and these delegations are responsible for embedding watermarks into the content. Nevertheless, if content owner does not trust the delegations, doing encryption is helpful in protecting treasurable contents in advance. Therefore, we include an effective cryptosystem into our watermarking procedures. Since additive homomorphism is a must for directly conducting watermark embedding in the encryption domain, the well-known additive homomorphic cryptosystem: Paillier is taken into account. Finally, the encrypted content size will be enlarged, with the aid of Chinese Remainder Theorem, we will show how to deal with this commonly faced troublesome issue in doing encryption.