A novel spatial region fragile watermarking algorithm based on the separable debluring is proposed. The watermarking message is hidden, firstly, in specific columns/rows of an image in a way similar to LSB. After a blur operation on the whole image, those columns/rows are discarded and replaced by random data to make the marked columns/rows unpredictable. At the receiver′s side, with the knowledge of blur and locations of the hidden messages, the separable debluring method is used to exactly unveil the hidden messages.Unlike previously proposed techniques, this novel approach provides information on specific locations of the image that have been modified. This allows the user to make application-dependent decisions concerning whether an image still has credibility.