ROBUST DATABASE WATERMARKING TECHNIQUE FOR NUMERICAL DATA

Abstract

The recent progress in the digital multimedia technologies has offered many facilities in the transmission, reproduction and manipulation of data. However, this advance has also brought the problem such as copyright protection for content providers. Digital watermarking is one of the proposed solutions for copyright protection of multimedia. A watermark embeds an imperceptible signal into data such as audio, image and video, which indicates whether or not the content is copyrighted. The Watermark is an informational bearing signal and it is an image or pattern identification that appears various shades of lightness/darkness. Watermark used on government document, currency. Watermark also used as security features of passport and other documents. Watermarking consist of embedding watermark with another signal like image, video signal. This process should not degrade the quality of signal. The watermarking communication channel is power limited and band limited. Due to requirement of imperceptible watermark, the power limit arise. And due to low pass multimedia signal like image, audio and video, the bandwidth limit arise. The Watermark signal is either unintentional or malicious interface, which distort the watermark. Claiming ownership rights on database is crucial issue in today's internet based application and in content distribution application. In this thesis we implement various techniques of database watermarking. In this we firstly encrypt the primary key and with the help of encrypted primary key we select the two tuple and then watermark it with the help of another tuple this method is also reversible.