A no reference image authentication scheme based on digital watermark

Abstract

A no reference approach based on digital watermarking is proposed for the authentication purpose of images undergoing some malicious or non-malicious attacks. It is no reference in the sense that it neither requires a reference image nor an external watermark. This feature makes the scheme attractive for situations where authentication of an image must be done without having an access to the original image or the reference watermark. The watermark is constructed from the image itself and is embedded as a robust signature in the image. The Discrete Wavelet Transform (DWT) is used to separate the approximation and detail regions of the image. The watermark is constructed from the low frequency region and embedded into the spatial domain by modifying the Least Significant Bits (LSBs) of each pixel. Upon comparison, based on metrices like Peak Signal to Noise Ratio (PSNR) and Structural Similarity Index (SSIM), authentication is ensured. Exhaustive simulations on the images from a well-known image database have been carried out to demonstrate the performance of the proposed approach.