Robust watermarking scheme for tamper detection and authentication exploiting CA

In this study, the authors have employed a special type of periodic boundary CA (called CA attractor) for image authentication and tamper detection through the watermarking scheme. Authentication code (AC) has been generated utilising secure hash algorithm-512 on watermark image. The cover image (CI) is subdivided into four sub-sampled interpolated image, where AC and secret watermark bits are embedded to enhance capacity, quality and security. At the receiver end, the secret watermark information and CI are successfully extracted without any distortion from four sub-sampled watermarked images (WIs). Additionally, the proposed scheme can successfully determine any type of distortion within the WI that may be possible to occur by various steganographic attacks. Indeed, better results in terms of capacity and quality are experienced after having compared with similar schemes in vogue. The intended outcome brought into the limelight some remarkable sublime characteristics in the field of image authentication and ownership identification without which the technology life is stunted. Innumerable government and private sector facet including health care, commercial security, defence and intellectual property rights are immensely benefited from this scheme.