Author : Subhash Rathod and A. K. Gupta

With fast advance of digital technology image processing is the fastest growing area of research and development. Sharing the data and authenticate the same is the big challenges now a days. To overcome the problem of pretending the documents as well as image as on his /her name, we invent the new method of an authentication and recovery of color tampered image using secure Shamir secret sharing method. The proposed method is an authentication and recovery technique for color images based on a Shamir secret sharing technique. An alpha channel signal which is used for authentication is generated for each block of a color document image, which, together with the binaries block content, is transformed into several shares using the Shamir secret sharing scheme. Care should be taken while selecting the parameter so that as many shares as possible are generated and embedded into an alpha channel plane. The alpha channel plane is then combined with the original image to form a PNG image. During process of image authentication, an image block is marked as tampered if the authentication signal computed from the current block content does not match that extracted from the shares embedded in the alpha channel plane. Data repairing is then applied to each tampered block by a reverse Shamir scheme after collecting two shares from unmarked blocks. By considering the lager database for images as well scan documents images with good experimental results prove the effectiveness of the proposed method for real applications.

Keywords: Data hiding, data repair, color documents image authentication, Portable Network Graphics (PNG) image, secret sharing.

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.4 (Aug- 2014)