未成年人上网内容过滤系统的设计与实现

【作者】 张沛强；

【导师】 吴振强；

【作者基本信息】 华东师范大学 ， 软件工程， 2008， 硕士

【摘要】 随着互联网技术的发展,Internet已成为当今世界最大的资源库。然而Internet上的信息良莠不齐,信息的随意浏览与发布,使得它在给人们带来便利的同时也产生了负面影响。如何有效防范互联网上不良信息对未成年人的危害,保护未成年人的健康上网是当今社会义不容辞的责任。论文在分析未成年人沉迷于网络的若干因素的基础上,认为造成这一现状的原因是互联网访问过程中缺乏有效、可控的管理机制。因此论文通过对家庭接入互联网的安全过滤技术和安全监管等内容进行研究,并利用各种过滤技术与方法对访问的网络内容和网站等进行严格控制,帮助家长对未成年人上网活动进行管理。从技术和监管的角度探索了对未成年人进行网络保护的方法。本论文的主要工作如下:1、分析了当前几款针对未成年上网内容进行过滤的产品的特点和不足,设计并实现了一款基于主机的未成年人网络内容过滤的开放性系统—网络保姆。该系统可以在家庭计算机上直接安装,具有安装简单、免费使用、易于配置等优点。2、论文分析比较了Windows环境下几种数据包截获技术的特点,研究了IP与TCP等包头的过滤技术。通过对特定的IP地址、TCP或UDP协议端口等的过滤,可以实现对特定网址和特定服务的限制。通过白名单机制,可以限制未成年人只能对指定的“绿色网站”进行访问,实现有效的安全控制与防护。3、考虑到网站的动态性和内容的不确定性,网络保姆系统实现了横跨驱动层、网络层、应用层的过滤模式,配合黑名单机制,对不健康或暴力内容的网页进行过滤,效果更好。4、通过对系统的功能和性能进行测试,证明该系统能够根据制定的网络访问策略有效地管理未成年人访问网络的行为,能够及时地阻断网络上的不良信息对未成年人造成伤害,实现了论文的初步研究目标。更多还原

【Abstract】 With the development of Internet technology, Internet has been the biggest resources depository in the world. While on the Internet, the good and the bad information are mixed together. Besides convenience, the arbitrary browse and release of information bring people a great negative effect. Although the current security tools, such as firewall, anti-virus software and intrusion detection system, do better in the prevention of security threats, these tools are mainly aiming at the security protection of enterprise network but not home network. This situation will cause a large number of young persons to be addicted to games, browse pornographic or violent website, and finally be guided to commit crime. So how to effectively protect young persons from harmful information and form a healthy climate of Internet use become a bounden responsibility in the current society.After analyzing the various reasons why many young persons are addicted to games, we find that the most important reason is the lack of effective and controllable management mechanism on the Internet. So the security filtering and supervision in home access to Internet are selected for researching in this dissertation. Meanwhile, several filtering technologies and methods are adopted to control the information which is released on the Internet. All the things we do will help the parents manage their children’s behavior of Internet use and protect the children from different angles such as technology and supervision. The main works are as follows:1. There are many deficiencies in the current content filtering products. For example, their filtering technologies are either too simple to use or relatively advance but the price of the product is very expensive. So the spread and popularization of Internet are affected in family area. In this dissertation, an open source system named Network Nanny, which is used for filtering network content ,is implemented. It can be installed directly on home computer, and have a lot of advantages, such as easy-installing, easy-configuring and charge free. 2. The supervision to the young persons’ behavior of Internet use. Several technologies of data packet interception on windows operating system are analyzed, while the filtering technologies of TCP/IP header are studied. By filtering some specific IP address ,TCP and UDP ports, the limitations to the specific URLs and service are realized. With the help of white list mechanism, young persons could only access specific green websites, and the security control and protection are realized effectively.3. The supervision to network content visited by young persons. Considering the dynamicity of websites and the uncertainty of network content, the Network Nanny realizes data packet interception on driver layer by adopting Winsock SPI on application layer. After that data packets are sent to application layer. So the system could realize multilayer filtering model from network to application layers and the filtering effect is very well. Cooperate with black list mechanism, unhealthy and violent websites can be filtered.4. After designing, debugging and programming, a system named Network Nanny is implemented on windows operating system. The performance testing results show that the system could effectively manage young persons’ behavior of Internet use according to the formulated network accessing strategy and timely blockade the hurt to young persons produced by harmful information on the Internet. In a word, the initial researching objective is realized.更多还原