Design And Implementation Of A Secure E-Mail System Based On PKI

As a common means of communication in the internet, e-mails are especially favored by businessmen since they can be sent timely, cost low and are easy to classify and organize. However the openness of the internet guarantees no security protection of the information while delivering. And most of the existing e-mail systems offer either no or simple encryption service which is insufficient for long-term users to send encrypted e-mails. Therefore, it’s significant to design a secure e-mail system to protect users’ privacy and trade secrets during emailing.After analyzed the modern encryption techniques, public key infrastructure (PKI) was chosen as the basis of the system design in this paper because of its applicable and strong security. Additionally, RSA and AES encryption algorithms were chosen to encrypt e-mails and other information in the system based on the analysis of common encryption algorithms. This paper represents the requirement analysis with use-case definition, and then illustrates the design of the system structure and the functional modules. Subsequently, the core structure has been constructed using the OpenSSL toolkit, and each module has been accomplished according to the instructions in the design. Then all the interfaces and functions have been tested after accomplishment, and an integration test has been done by connected to the mobile client to ensure that the system can send e-mails safely and correctly.By using the widely accepted PKI technology, an e-mail encryption system has been built to solve the traditional e-mail security issues. Now the system has been deployed on the public network, and the trial users can send and receive encrypted e-mails via the mobile and Wifi network.