An asymmetric image watermarking scheme resistant against geometrical distortions

In this paper, a novel asymmetric public-key watermarking scheme for static images is proposed. The watermark is embedded with the use of a private key, while the decoding uses only a simple public key. The asymmetric watermark carries certain number of bits of information. However, neither the knowledge of the public key, nor the knowledge of the hidden information, allows the attacker to remove the watermark. That information can be read from an attacked image, in particular from a geometrically transformed image. Moreover, the proposed watermark could be used as a synchronization template for another private-key watermark. (C) 2005 Elsevier B.V. All rights reserved.