Design That Individualized KDC Acts As Agent Under The Distributed Environment And Realizing

The thesis is study individualized design that KDC act as agent and realize under distributed environment. Distributed environment mean time, space, realize means, systematic platform operation terms different for use. In the distributed and networked information system, every user is distributed in environment , but must run in coordination with the whole system could finish crossing over the time, space. The agent refers to a kind of computer program that called software acts as agent. It can adopt behavior of autonomy, through mutual with environment in order to finish the definitely work. Put forward in text that individualized acts as agent to be kinds of simple KDC system, utilize KDC security, can trusting, and some relevant institutional framework, produce and manage the key system according to the individualized information that users offer, session key, public-key and acting for users to converse. Produce individualized KDC can remove the work of KDC system , KDC keep the all public-key only, when users need public-key to distribute with authentication, sign. What merits attention is KDC acts as agent to be encapsulation , independent to users, its purpose is for the key's security, avoid divulging a secret artificially, strengthen the systematic security, reduce work load of user, raise efficiency that converse, have effective differentiation news source very, confirm the news integrality and resist the denying function.The agent of KDC producing key on the basis of users' individual character information, it adopts the digital watermark technology based on colored static digital picture to hide users' individual character information in the corresponding picture, use RSA algorithm to produce the public-key and private key, and utilize the Diffie-Hellman algorithm safe conveying toKDC system; As to session key system , use algorithms of one-time key that put forward in text producing.The thesis depends on cryptography and mathematics, digital watermark, user individual character information hide , public-key and session key's production,custody, etc. Have analysed about the security of the algorithm, such as attack voluntarily, attack passively, key management.The key content of the thesis is session key system, it is a foundation of the security conversation. The agent of KDC according to the picture and individual character information which users input, the base key of producing automatically, make the conversation every side produce the self-same main key, has solved the problem of key distribute ingeniously. And it utilize irreversible hash function produce session key realize one-time key. The thesis has also analysed the application of different situations that the agent of KDC among the conversation modes in many ways.The research results of the thesis can lighten the burden of KDC system to a great extent, reduce network load, and can key produced with users' individual character information also, make attacker not have a primitive information source of sureness. The algorithms of one-time session keys can keep out the attack passively and attack voluntarily(mainly mean that the man-in-the-middle attack), and increase degree of difficulty of cryptanalysis, strengthen the security of conversing.