Triple Key Chaotic Encryption And Secret Sharing-Based Method For Authentication Of Color Document Images Via The Use Of The Png Image With A Data Repair Capability

In this paper for improving the security of data transmission we are introducing triple key chaotic encryption technique .In addition to this authentication method based on secret sharing technique with a data repair capability is being introduced. Using Shamir secret sharing scheme shares arebeing created from the authentication signal generated for each block of document image alongwith the binarized block content As many shares as possible are generated by properly choosing the involved parameters.PNG image is formed by combiningalpha channel plane with original image.To yield atransparent stego image the computed share values are mapped in to a range of alpha channel values near to their maximum value of 255 during the embedding process.authentication of the document image can be changed by an intruder by superimposing ,painting or adding noise to the image.image is marked as tampered if there is a mismatch between the authentication signal of the current block and that extracted from the shares embedded in alpha channel plane.reparing of data is being done by applying reverse Shamir scheme by collecting shares from the unmarked block.