Design And Implementation Of An Examination System For Vocational Certification And Training Based On Multi-layer Security

In recent years,both at home and abroad are constantly carrying out a series of industry certification exams,such as MCSE,CCNA,CCNP,CISP and so on.With the application of multimedia and artificial intelligence technology on the network,the vocational certification exam format is also moving towards informationization.The existing examination system generally has many shortcomings,such as the lack of diversity in question type,insufficient safety,and high difficulty to meet the needs of actual examination.Once private information in data-intensive application systems like vocational training and certification examination system,for example,candidate registration information,subject information and grade information,has been leaked,the privacy of users and the fairness of the exam will be seriously affected.In view of the deficiency of the existing certification examination system,this paper studies key technologies required for the development of the certification examination system and conducts in-depth investigation and analysis on security issues of current popular Web application systems.In the light of software security development lifecycle,the security strategy of the system is researched and implemented,combined with multiple security levels,such as operating system layer,middleware layer,code layer and application layer.Focus on permission authentication,database security and code security in the system platform,the common interfaces for authorization are extracted and a database encryption system is set up,and then the implementation of interfaces about code safety is completed.The combination of safety design standards,expert experience and best practices in safety is applied to all development stages to enable system safety.Combined with LAMP(Linux + Apache + MySQL + Perl/PHP/Python)dynamic web site architecture,ThinkPHP framework and other web development technologies,the system function modules such as certification registration,course study,online exam,Q&A column,forum and backstage management are able to be completed successfully.At the same time,the paper studies the algorithm of random test and the genetic algorithm in the test paper and the mathematical model of the algorithm is established and implemented with main control parameters including the question type,question amount,total score,exam difficulty and knowledge distribution.By comparing the performance of the two algorithms,such as the average time and the success rate of test assembly,and the repetition rate of test papers in different quantities of questions,a good reference is eventually provided for test strategy selection.