  Based on fixed point theory, this paper proposes a new scheme for image
integrity authentication, which is different from Digital Signature and Fragile
Watermarking. A realization of the new scheme is given based on Gaussian
Convolution and Deconvolution (GCD) functions. For a given image, if it is
invariant under a GCD function, we call it GCD fixed point image. An existence
theorem of fixed points for GCD functions is proved and an iterative algorithm
is presented for finding fixed points. Experiments show that GCD fixed point
images perform well in transparence, fragility, security and tampering
localization.
