Design And Implementation Of Distributed Cipher Cracking System Based On Mobile Agent

Public security organ has played an important role in the prevention, controlling and strike on offences and crimes, and the maintenance of social stability. With the great development of science and technology, especially that on the computer and Internet in the twenty-first century, the criminals have an intelligent trend in crime means, using a lot of assistant tools in their machination and collusion, such as Word,QQ,MSN,E-mail. Simultaneously, they usually use more complicated passwords with the increasing of their safety and anti-detection consciousness. So a great problem that the public security organ tackles is how to attack targets'secret cores, find out the clues, fix the evidence and track the criminals by analyzing their passwords.Making full use of network resource to implement high-paralleled and distributed computation is an important way of password decoding. Mobile Agent technology is a new distributed computation with the quality of independence, mobility, reactivity, motility and asynchronism, so it is a new idea to design the password decoding systems.In the project, firstly, Mobile Agent based Distributed Cipher Cracking Model (MADCCM) was researched and built, and the Model's arrangement structure and its system framework were designed, as the Model's operation flow and main Agent module functions were described in detail. Secondly, the key techniques on task disassembly and allotment, communication mechanism, transference scheme, and the fault-tolerant strategy were emphatically analyzed and studied to the MADCCM. Sub-task disassembly and allotment were implemented with the techniques of password interspaces, primary disassembly and second disassembly. The settings of register table and sign-bit were used to solve the problems on transparent locating and communication invalidation of Mobile Agent. As the concepts of obvious migration and connotative migration were created, the occasion on connotative migration was confirmed and the process of migration of Mobile Agent was described in detail. The methods of Agent's rebuilding and sub-task's recomputing were adopted to solve simply the fault-tolerant problem on the model. Then, Aglet 2.0 that IBM Corporation developed was used as the Mobile-Agent system platform. The certain functions on the model were realized with JAVA technology, and the system was checked and analyzed on its capability to testify its rationality and usability. At last, the main summarized research work brought forward the further problems on t Distributed Password Decoding Systems based on Mobile-Agent, and it indicated the direction of the further research.Innovative research in this paper includes the following points: 1. Propose the model of MADCCM by researching the theories of mobile Agent and Distributed Cipher Cracking system.2. Design the arrangement structure,system framework,operation flow and main Agent module functions of MADCCM.3. Solve the key techniques on task disassembly and allotment, communication mechanism, transference scheme, and the fault-tolerant strategy.4. Indicate the feasibility and advantage of using mobile Agent in cipher cracking by realizing and testing the certain functions of the model.