Research And Realization Of The Secure System Of China Mathematical Contest In Modeling Based On PKI

In recent years, Internet-based examination systems have come into being. Network Examination thoroughly changes the traditional way of examination. Traditional examination needs to give out examinenation papers and submit answer papers with manual mode, so it makes the procedure of examinenation cumbersome, slow and inefficient. Network examination makes examination become convenient, efficient, paperless with automation mode. It can save a lot of manpowers and material resources. However, it offers much convenience, at the same time ,many new problems about security come into being.In this thesis, aiming at the four problems of downloading the contest paper simultaneou -sly , submitting the answer papers simultaneously, validating the identity of players and validating the integrality of answer paper in the China mathematical contest in modeling ,a corresponding PKI-based security solution is put forward with the help of comprehensive application of data encryption, digital signature ,digital certificate and time-stamp technique to solve a series of security problems such as privacy, integrality, undeniability and cheat-preventing . At the same time , the problem of time efficiency in the process of downloading is solved with the help of encryption and the problem of the time efficiency in the process of submitting test paper is solved with the help of time-stamp. The system issues information in B/S and carries out paper encryption ,digital signature and time-stamp functions in smart client program. starting from the use case model analysis, database design and functionality modular design ,this thesis depicts the workflow of the overall system.On the basis of theory research and analysis, the author establishes CA of the China mathematical contest in modeling in Windows 2003 environment, and establishes the PKI-based framework of the time-stamp service in the core of CA. In Visual Studio 2005 and .Net Framwork 2.0 environment, the author develops a smart client program for contest test with paper encryption ,digital signature and time-stamp functions, which can be used to the China Mathematical Contest in Modeling .