Security Research And Improvement Of E-mail System Based On Network Protocol Analysis

With the popularity of the Internet,e-mail system has become one of the important communication tools because of its advantages,such as: diversity of content format,low cost of communication,and store-and-forward model.More and more enterprises are also beginning to use the e-mail system to carry out work exchanges to improve their work efficiency.The e-mail system brings great convenience to people's life,but it inevitably brings some security problems.Therefore,it is imperative to strengthen the research on the security of e-mail system.Firstly,this research analyzes working principles and structure of e-mail system and network protocols related to e-mail system.Secondly,based on the above analysis,this research analyzes the security of existing e-mail system in three aspects:user's identities certification,e-mail sending process and e-mail reading process;gives a case of recovering the content and attachment of WebMail to illustrate the possibility of leaking sensitive information.Thirdly,this research proposes a symmetric encryption algorithm based on chaos theory and encapsulates the encryption algorithm into a chrome plugin.Experiments show that the encryption algorithm proposed in this research realizes the encryption of plaintext,and the decryption of ciphertext.Otherwise,the decryption will failure.The secret key in this encryption algorithm is generated randomly,so the encryption algorithm realizes function of dynamic session secret key,which increases the difficulty of breaking secret key.In addition,the encryption algorithm can hide the static probability of plaintext in ciphertext by one-time pad.All in all,this encryption algorithm has high security.The browser plugin realized in this research apply the encryption algorithm to encrypt content and attachment of WebMail.With this browser plugin,users can encrypt content and attachments of WebMail expediently.