信息安全導(dǎo)論課程-ch15-電子郵件安全-全文預(yù)覽
【正文】 ? Windows里的文件加密 – EFS(須 NTFS) – 試驗(yàn)這個(gè)功能 ? 先以一個(gè)一般用戶的身份加密，再試圖用管理員權(quán)限讀 ? 一般不同用戶的文件的互訪問可能 (?) ? 關(guān)于備份員 B 案例分析 ? 先看一個(gè)短文 –Google(“加密的慘劇 ”) ? 試用網(wǎng)上某些文件加密工具 –“值得一提的是它的加密速度極快，上百 G 的數(shù)據(jù)僅需 1秒鐘完成。 B SMTP/POP3 ? SMTP – 制做假冒郵件 ? POP3 ? IMAP,… B EMail: ? SMTP – RFC 821 SMTP Simple Mail Transfer Protocol ? POP3 – RFC 1939 POP3 Post Office Protocol – V3 ? IMAP – RFC 2060 Inter Message Access Protocol ? allows a client to access and manipulate electronic mail messages on a server ? X400 – X400 is a whole of protocols adapted to EDI B EMail software * Client: Outlook/Exp, Foxmail, Eudora * Server: Sendmail, Exchange, Exim, Qmail, Postfix SMTP Server Survey // 958 All ? 401 UNIX Sendmail ? 176 Windows Microsoft Exchange or IIS SMTP ? 167 UNIX qmail ? 57 Windows Ipswitch IMail ? 23 UNIX smap ? 15 UNIX IBM Postfix, formerly VMailer ? 14 UNIX Exim ? 12 Windows Gordano NTMail B SMTP HELO SP domain CRLF MAIL SP FROM:reversepath CRLF RCPT SP TO:forwardpath CRLF DATA CRLF RSET CRLF SEND SP FROM:reversepath CRLF SOML SP FROM:reversepath CRLF SAML SP FROM:reversepath CRLF VRFY SP string CRLF EXPN SP string CRLF HELP [SP string] CRLF NOOP CRLF QUIT CRLF TURN CRLF B SMTP model ? ++ ++ ? ++ | | | | ? | User || | SMTP | | ? ++ | Sender |Commands/Replies| Receiver| ? ++ | SMTP || SMTP | ++ ? | File || | and Mail | || File | ? |System| | | | | |System| ? ++ ++ ++ ++ ? ? SenderSMTP ReceiverSMTP ? Model for SMTP Use B Extended SMTP ? rfc1869 SMTP Service Extensions ? EHLO (Extended HELLO) – rather t
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號-1