In this dissertation, a novel multipurpose digital watermarking scheme based on single value decomposition (SVD) is proposed. Such a scheme can be applied to both content authentication and copyright protection. In the proposed scheme, two watermarks are embedded in different single values of the SVD domain. A robust watermark is embedded in the first stage, where as a fragile watermark is embedded to the image using a quantization technique in the second stage. Experimental results demonstrate that the proposed scheme is resistant to image faking, image cropping, JPEG compression, noise adding, image filtering, image scaling, and image rotation.