Double Security Watermarking Algorithm for 3D Model using IEEE-754 Floating Point Arithmetic

Most of the fragile watermarking scheme authenticate the user but unable to locate the region of tampering. The objective of proposed scheme is not only maintaining the quality of watermark 3D object at its acceptable level but also identify the region of tampering. During the process of watermarking embedding the normal distance of each vertex from center of mass is calculated and marked vertices are converted into IEEE-754 floating point representation in double precision. Cryptographic hash function is applied to find the mark vertices. The watermark is inserted in each of the segments of 3D model so that authentication may be done through any of the segment. Fragile watermarking technique is used for authentication in case of multiple user claims for the single object. It is very important to protect and authenticate the 3D model. Keywords copyright protection; hash function; payload; cover object