K. J. Somaiya

Sharing of copyright documents, images, audios, and videos on Internet has become easier due to content authentication using digital watermarking. It also finds applications in the area of content protection, copyright management, and tamper detection. With the use of sophisticated signal/image processing algorithms, manipulations and duplications of audio, images, and videos are much easier. Hence, content authentication through encryption and resistance to general attacks such as noise, compression, and geometric has become an urgent and important issue. In this study, authors have proposed digital image watermarking technique based on discrete wavelet transform (DWT) and encryption. Watermark embedding and extraction algorithm using DWT coefficients, distance measurement, and encryption are demonstrated. DWT through multiresolution analysis provides the much needed simplicity in watermark embedding and extraction through watermark encryption. The technique results in PSNR greater than 50 dB and is resistance to noise, geometric, and compression attack. The proposed technique may be applied for copyright and content authentication applications.