Challenges of Multimedia Watermarking Techniques

Abstract

Data transmitted through a network may be protected from unauthorized receivers by applying techniques based on cryptography. Only people who possess the appropriate private key can decrypt the received data using a public algorithm implemented either in hardware or in software. Fast implementation of encryption-decryption algorithms is highly desirable. Data-content manipulation can be performed for various legal or illegal purposes (compression, noise removal or malicious data modification). The modified product is not authentic with respect to the original one. The technology of multimedia services grows rapidly, and distributed access to such ser-vices through computer networks is a matter of urgency. However, network access does not protect the copyright of digital products that can be reproduced and used illegally. An efficient way to solve this problem is to use watermarks. A watermark is a secret code described by a digital signal carrying information about the copyright property of the product. The watermark is embedded in the digital data such that it is perceptually not visible. The copyright holder is the only person who can show the existence of his own watermark and to prove the origin of the product Reproduction of digital products is easy and inexpensive. In a network environment, like the Web, retransmission of copies all throughout the world is easy. The problem of protecting the intellectual property of digital products has been treated in the last few years with the introduction of the notion of watermarks.