Fragility evaluation of intermediate significant bit embedding (ISBE) based digital image watermarking scheme for content authentication

Digital image watermarking is being extensively used for protecting sensitive image data transmitted over insecure channels. Watermarks are primarily used for two fold operations, copyright protection and content authentication. Robust image watermarks are used for copyright protection and fragile watermarks used for the content authentication. In this paper fragility evaluation of a fragile image watermarking scheme has been carried out to ascertain the areas where the embedded watermark could be more fragile. The embedding has been carried out in spatial domain in various image bit planes using Intermediate Significant Bit Embedding (ISBE). The evaluation has been carried out by subjecting the watermarked image to various image processing attacks like histogram equalization, Low Pass Filtering, addition of white Gaussian noise, JPEG compression etc. The experimental results show that irrespective of the nature of attacks the higher the order of bit plane in which data is embedded lower the fragility of the system and vice-versa.