合作式垃圾信件過濾系統

Abstract

在網際網路上，電子郵件已經成為了最重要的應用軟體之一，最近這幾年，網路的管理者及使用者花了很大的心力在對付惱人的問題，那就是垃圾信件，垃圾信問題的嚴重性在於發送垃圾信的人只要花很低得成本就能夠從垃圾信上獲得相當大的利益。 在本論文，我們設計且建立了CASEF系統在路由的階段來過濾垃圾信件，我們的方法主要是利用垃圾信會在短時間內發送大量且相同信件的特性，除此之外，我們也建立了垃圾信誘捕系統來幫助CASEF系統，我們的CASEF系統不僅能在路由的階段來阻擋相同的垃圾信也比SpamAssassin有較高的準確率。

Email has become one of the most important applications on the Internet. In recent years, system administrators and Internet users had tried their best effort to solve the annoying email spam problem. The problem is that spammers can send huge amount of junk emails with a low cost and then get a large reward from the spam. In this thesis, we design and implement the CASEF system to filter the spam at the router level. Our proposed method exploits the property of the spam that is distributing lots of identical spam mails at the same time. Moreover, we also implement an email honeypot to capture the spam mails to augment the CASEF system. Our CASEF system not only defends the repeated spam mails at the router level but also has a higher accuracy than SpamAssassin.