Block–wise authentication method for digital images

The ability to modify digital images can cause a serious problem in some applications. In this paper we propose a novel method derived from Wong’s authentication scheme that is capable of authenticating JPEG images as well as uncompressed images, but is not a watermarking method. The method offers great flexibility in terms of the size of the authenticator and the time needed to generate the authenticator, thus making it suitable for real-time image processing. We demonstrate this by implementing it in a programmable FPGA circuit.