Review on Methods of Authentication of Images with Data Repair Capability

Image authentication methods based on conventional cryptography, fragile watermarking, semi-fragile watermarking and on image content signatures discussed in this paper. For each group of methods the type of the authentication tag, the dependency of this authentication tag on the image, the type of the authentication service provided are shown, that is strict or content-based (selective) image authentication service, the localization capacity of the altered regions, as well as the possibility of restoration of image corrupted regions. Algorithms are also grouped according to the authentication tag that is used, and references are included. It can be noticed that one principal property of an image authentication system, the detection of malevolent manipulations. According to the summary table, algorithms performances are very similar. In fact, most of algorithms offer acceptable detection and localization of image manipulations while restoration performances still need to be improved.