Binary image authentication using zig-zag ordering of watermark

Digital documents have been widely used for various applications. Various sophisticated image editing tools are available in market. Because of this, ensuring authenticity and integrity of the digital documents have become the major concern today. Here a technique is proposed for tamper detection of binary images. Image is partitioned into 3 × 3 block. The embeddability of a pixel is determined through a connectivity criterion. For making this technique strong watermark is encrypted using encryption techniques and distribution of watermark, over the image is done using zigzag ordering technique. Blind detection of the watermark can be done on the receiver side and authenticity of the image can be detected. Experimental Results shows that zigzag ordering distributes watermark over the image and tampering with the image can be easily detected without any additional information.