Key controlled-based secure spatial digital image watermarking using randomized pixel embedding

Rapid advancements in digital communication over the last decade increased the digital image transmission through the Internet, difficulties of confidentiality, and the legitimacy of the image owner has been compromised. Therefore, digital image watermarking is employed as a one of the solution. In this paper, a novel spatial domain strategy is proposed to achieve confidentiality and authenticity in digital image transmission through the Internet. To maintain security and imperceptibility, the cover image is partitioned into 4 × 4 non-overlapping blocks, and high-entropy blocks are chosen at random. Further using the Blum-Blum-Shub pseudorandom generator, embedded pixel positions are selected adaptively. To ensure high watermark security, the watermark is encrypted with a pseudorandom key generated through a linear congruential generator. The suggested method is assessed in terms of imperceptibility, robustness, security, and computational time. The experimental findings reveal that the suggested technique is imperceptible (Avg. PSNR = 60.26 dB and Avg. SSIM = 0.99) calculated for 50 images with an embedding capacity of 0.0625 bpp. It is resilient to most of the attacks (Avg. NC = 0.9999, Avg. BER = 0.00002 Under zero attacks). Comparative analysis with some of the recent popular schemes further affirms the effectiveness of the scheme.