Study And Implementation On Identity Authentication Of The Exam System

With the development of campus network, paperless examination is applied in the vocational and specialized colleges widely. But there is potential safety hazard inevitably in it. It is important and worth to in-depth research to guarantee the security of the examination. Identity authentication technology is especially important as the first pass of the system.In-depth investigation and comprehensive introduction on cryptography theory and technology which are related with identity authentication were carried out in this paper firstly. Based on the analysis of the disadvantage of existing digital signature solution, An improved digital signature solution was proposed which combines the advantage of symmetrical key algorithm, asymmetrical key algorithm and unidirectional hashing function. It successfully solved the problem of symmetrical digital signature caused by the difficulty to store key and indispensability of arbitrator. And it also avoided the disadvantage of asymmetrical digital signature that it was too slow to suit for the long file signature.The demand of the safe RSA asymmetrical key cipher system to prime number was investigated. Considering the shortage of slow operation sp??caused by complex model and power operation in the traditional large prime number generation method, an optimized method for large prime number generation which was based on the Miller-Rabin probabilistic prime number detection method was proposed. The number of judging times in this method was cut down by improving the Miller-Rabin probabilistic prime number detection method, and the scope of test was reduced by being filtered using little prime number. Searching large prime number was accelerated effectively.Aiming at the shortage of strong prime generation methods, a new method was proposed. Based on the character of the strong prime, strong prime was generated by using top-down construction method. It's easy to realize and good enough to satisfy the request of the security of RSA algorithm.Finally, analysis and comparison of several well-known identity authentication technology such as based on secret knowledge, smart card, and biological features etc were completed. By using the digital signature solution solution designed in this paper, a simple and practical bidirectional identity authentication solution in the client and the server is proposed, and this solution is realized using the .NET cryptography technology in the C# platform. This solution could meet the system structure and security demand prescribed in the research project named Paperless Examination System in Vocational and Specialized Colleges Based Campus Network which is established by the education department of Hunan province. After validation of the user's name and password, a digital signature was applied to confirm the identity of user further more. Participation of the third party organization and additional authentication equipments were not needed in the whole process. The security performance and easiness to realize of this solution is good enough for examination system under building. And because it is easy to be transplanted to other information management systems, it has good application prospect.