The Research Of Digital Image Sharing Based On Chaos And Threshold Scheme

In information times, more and more information has been quickly and conveniently transmitted through the network, and which has brought the potential problems of the security of information at the same time. Therefore, the security of information is getting more and more important. The cryptography, which aims at the security of information, has become the important research fields in information science and technology. Up to now, data encryption technology is the best method to obtain information security undoubtedly; it is greatly practical and urgent to develop key technology.Based on chaotic systems with good properties such as ease of generation, noise like statistic characteristics and sensitive dependence on their initial condition and system parameter, chaotic theory and digital image encryption are combined, which can design the better system of image encryption. Digital image encryption algorithms based on the chaotic theory have been researched in this paper.Secret sharing scheme plays an important role in Key Management. With the development of the informatization all over the world, the number of department in enterprises has become more and more larger and complex. At the same time, the Keys of the department has increased quickly. The Secret Sharing targeted the multilevel structures becomes the new technology. Aiming at this, this paper discussed the Secret Sharing trifurcate tree organization oriented on the (t , n) Threshold , which is targeted on the multilevel structures.On the base of what was discussed above, the main contributions of the paper are:(1) Knapsack of Public-key system is very important in Public-key system. We presented the fundamental knapsack system. Then we put forward an encryption algorithm by Matthews Chaos system and addition operation. It has many advantages such as high speed and high security, but this algorithm is not fit in image encryption.(2) Based on understanding permuted algorithms of the digital image and their properties, discussed the specialties of Logistic map. We presented an image encryption algorithm, which was called XZQ algorithm. And then we improved the algorithm by adding image feature in it. And the new algorithm is very sensitive to plaintext image and the security remains as before.(3) With the development of the modern enterprise and the require of Key Management, the traditional two-layer sharing scheme is not adapted. So we researched the department structure of the modern enterprise , and then put forward a scheme of trifurcate tree organization structure-oriented which is adapted in modern enterprises.And the scheme comprehensiv utilized of Chinese Remainder Theorem(CRT), Langrage interpolation, in order to realize the image sharing.(4) This paper developed the software to encrypt image by Chaos and to share the image in trifurcate tree organization structure by Visual C++ tool.