Robust Watermarking Scheme for Digital Image Authentication and Security

In the present era, safeguarding information holds paramount importance as organizations are grappling with data security challenges due to the advancements in the technology. Coping with the exponential growth of data poses a daunting task for researchers, particularly when it comes to safely and effectively managing vast amounts of data. Consequently, verifying the authenticity of digital content has emerged as a significant concern, given that such content is generated and shared online on a daily basis. In light of these concerns, a robust authentication watermarking method was presented to safeguard documents by identifying appropriate attributes within them. Accordingly, the image was split into various blocks, with different block sizes for the inner and outer parts. The watermark was then embedded into both sections of images using different transformations: namely Discrete Wavelet Transform (DWT) for inner sections and Discrete Cosine Transform (DCT) for outer sections. Experimental results reveal that the proposed scheme maintain high image quality after watermarking, with a PSNR value of 35 db even after JPEG compression. The embedding process ensures acceptable image quality following tampering attacks such as JPEG compression, Gaussian noise, and scaling. Furthermore, Normalized Cross-Correlation (NCC) value of 1 was attained under no attacks with values ranging from 0.9014 to 0.9999 under different attack scenarios. The result show that the watermarking algorithm offers greater robustness, security, and resistance compared to other methods in the literature making the proposed method suitable for critical applications in areas such as copyright protection, secure content distribution, and digital forensic analysis.