The Design And Implementation Of Security Toolkit And Security Email System

With the popularity of computers and the development of the Internet, various applications of computer network have remarkably affected all aspects of our life. The Internet not only promotes the development of the society and the science, but also improves the quality of our life. However, it also bring us a sequence of information security problems.The foreign countries usually limit the export of products of high security level severely, and conceal the internal implementation details of most of their security products, which leads our information security systems to an unreliable state. At the mean while, as one of the most early and popular applications of the Internet, the E-mail has been confronted with the more and more severe security problems. Especially some illegal or adverse persons often use the E-mails to pursue some activities against our party, people and socialism. In allusion to these phenomena, this paper has designed and developed a toolkit of information security CIST with host copyright, as well as a new safe E-mail system based on CIST(SEMS ).CIST's collectivity design is isolated from the external codes. Compared with other security toolkits, CIST has some advantages, such as high security and powerful expansibility. During the process of SEMS's design, we make full use of the advantages of both the existing E-mail security protocols and the safe E-mail systems, and try to conquer their disadvantages and deficiencies, which enhances the security of data and contexts in E-mails.This paper puts emphasis on the encryption technology which is tied up to CIST and SEMS, and some predominant information security toolkits and famous E-mail security protocols are analysed, such as PEM, S/MIME and PGP. In allusion to the problem that the operation of security toolkit CIST is usually complex, we design and implement an upper object of CIST-envelope object. By designing the envelope object's action list and context list, the crucial technique problem of the envelope object's intelligentization is settled, and users can use CIST more conveniently. At the mean while, this paper designs and implements a new safe E-mail system SEMS, whose kernel techniques include E-mail security agent, multi-level E-mail filter, the combination of static strategy and dynamic strategy, and the combination of the rule basis and the statistic basis. With the security agent, the system has conquered the hidden trouble due to the PGP protocol lacks special CA framework. With the multi-level E-mail filter, the system can give attention to both the filter's reliability, processing speed and the service performance. The E-mail statistic list is designed to create automatically the e-mail website, which promotes the quality of the E-mail filter more. What is more, during the design of the SEMS, ECC and improved IDEA algorithm are introduced in place of the normal RSA algorithm and the standard IDEAalgorithm respectively, which improves the E-mail system's security likewise.