局域网垃圾邮件监控及过滤技术的研究

发布时间：2018-10-04 23:26

【摘要】：随着Internet的迅速发展，人们在互联网之间的交流也越来越普及。电子邮件作为互联网上的通信服务，以方便快捷的传输方式和低廉的价格得到了广泛的应用，，并且成为了人们日常生活中的重要组成部分。但是电子邮件在给人们带来极大便利的同时，也带来了一系列的网络安全问题。垃圾邮件的泛滥成灾就是其中之一。不仅对人们的日常收发邮件造成了困扰，部分恶性垃圾邮件还会携带不良信息、钓鱼网站或者木马病毒，给收件人带来严重危害。因此为了减少网络中的垃圾邮件，为用户提供一个安全的收件环境，开发一个可用可靠的局域网垃圾邮件监控和过滤系统是十分重要的。本文深入分析了电子邮件在网络中的传输原理，在此基础上提出了一套采用旁路监听模式、使用软硬件相结合的方式进行局域网垃圾邮件的监控和过滤的思想和方案，并且实现了系统方案中最基本也是最重要的模块。经过实际网络环境下的测试实验，验证了本系统方案中已实现的功能是可用的，在局域网环境下可以准确地监控并还原邮件文本，并且在准确率与内存使用率等指标上达到了预期效果。本文的主要工作如下：首先阐述了课题的研究背景和研究意义，介绍了垃圾邮件过滤系统在国内外的研究现状。接着讨论了局域网垃圾邮件监控和过滤技术涉及的基本原理。随后，本文从接入网络的位置出发，对比分析了局域网垃圾邮件监控及过滤系统的几种实现方案，阐述了最终采用旁路监听模式的可行性与优点。在确定系统的网络架构之后，本文进一步确定了系统的软件构成，然后根据邮件还原的流程，对邮件还原这一重要模块进行了详细的分析与设计，并且使用Libnids网络安全开发工具实现了邮件的还原。最后，本文对系统中已实现的模块进行了功能性测试和内存使用量测试。本文提出的局域网垃圾邮件监控和过滤方案，具有对用户资源占用少，对局域网正常通讯影响小，接入方式灵活方便的特点，根据方案的实际需要，已实现的模块具有很强的可扩展性和可维护性。另外，在邮件还原模块的设计中，本文解决了一个关键技术：如何管理局域网同一时刻中正在接收的多封邮件。
[Abstract]:With the rapid development of Internet, communication between the Internet is becoming more and more popular. As a communication service on the Internet, email has been widely used with convenient and fast transmission mode and low price, and has become an important part of people's daily life. But email not only brings great convenience to people, but also brings a series of network security problems. The spamming of spam is one of them. It not only makes trouble for people to send and receive emails, but also brings bad information, fishing website or Trojan horse virus to the recipient. So it is very important to develop a reliable LAN spam monitoring and filtering system in order to reduce the spam in the network and provide a secure collection environment for users. This paper deeply analyzes the principle of email transmission in the network, and puts forward a set of ideas and schemes to monitor and filter spam in LAN by using the mode of bypass listening and the combination of software and hardware. And has realized the most basic and the most important module in the system scheme. Through the testing experiments in the actual network environment, it is verified that the functions realized in this system are available, and the mail text can be monitored and restored accurately in the LAN environment. And in the accuracy and memory utilization rate and other indicators to achieve the desired results. The main work of this paper is as follows: firstly, the research background and significance of the subject are described, and the research status of spam filtering system at home and abroad is introduced. Then it discusses the basic principle of LAN spam monitoring and filtering technology. Then, starting from the location of the access network, this paper compares and analyzes several implementation schemes of the local area network spam monitoring and filtering system, and expounds the feasibility and advantages of the final adoption of the bypass monitoring mode. After determining the network structure of the system, this paper further determines the software structure of the system, and then, according to the flow of mail restore, the important module of mail restore is analyzed and designed in detail. And the use of Libnids network security development tools to achieve the restoration of mail. Finally, the functional test and memory usage test of the implemented modules in the system are carried out. The local area network spam monitoring and filtering scheme proposed in this paper has the characteristics of less occupation of user resources, less influence on LAN normal communication, flexible and convenient access mode, according to the actual needs of the scheme. The implemented modules are extensible and maintainable. In addition, in the design of mail restore module, this paper solves a key technology: how to manage multiple messages that are being received in LAN at the same time.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.098

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