Research On Authentication Algorithm Combining Dual Chaotic System And Digital Signature

With the rapid development of digital product, and the gradual popularization of the internet, they brought great convenience to people's routine work and life. Just like music, image and video etc digital media has become the object who was acquired, copied and spread by illegal, because people enjoy these visual products. However, everything has two sides, when the internet is convenient for the people's daily life, but also brought huge potential safety problems. More and more the information is tampered, and the copyright is infringed by illegal activation for the openness and sharing of internet, the interest of copyright holder and users are seriously harmed. So it is necessary to have a new technology for protecting the copyright, authenticity and integrality of digital product, and private of users.In this paper information hiding and authentication is the objective, digital watermarking technology is the starting point, image encryption technology is the guarantee, and digital signature technology is the method. The experimental results show that the digital product have stranger resistant attack ability, higher imperceptibility, and also this algorithm could protect and track copyright. This dissertation is mainly focus on the following works: Firstly, the concept, method of digital watermarking technology is illustratedin detail. Embed watermark algorithm is propose based on Contourlet transform, and plentiful experiments are done from the generating, embed to extract of watermark. Last, this algorithm allows an effective resistance from various attacks on the embed-watermark image.Secondly, the concept, method of image encryption technology is illustrated in detail. A dual chaotic system is proposed which combined with piecewise Logistic chaotic map and Cat chaotic map. The dual chaotic system is improved based on the original Logistic chaotic, and can be keep chaotic state better.Lastly, digital signature technology plays an important role in protecting copyrights of digital product, preventing the private of digital product as well as providing authentication. A new algorithm combining Contourlet transform with digital signature is proposed. The experiment result shows that the algorithm has better safety and practicability for the authentication of author and the interest of users.The feasibility and effectiveness of three methods had been demonstrated through extensive experiments conducted on digital signature.