一段明文如何加密为密文

发布网友发布时间：2022-04-29 17:27

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热心网友时间：2023-07-14 14:51

可以用古典密码进行加密

古典密码常用的有凯撒加密等等

要好理解的话我说一下吧

比如明文 abcd 密钥 5 密文 efgh 就是将字母顺序向右移动五位（位移5）

现在用凯撒密码加密一句话 i love you

密文为n qtaj dtz

还有一个反字母表加密

字母表 abcdefghijklmnopqrstuvwxyz

反字母表 zyxwvutsrqponmlkjihgfedcba

比如 abcdefg 加密后为 stuvwyz

Function Caesar(str, offset)
Dim length, char, i
Caesar = ""
length = Len(str)
For i = 1 To length
char = Mid(str, i, 1)
If char >= "A" And char <= "Z" Then
char = Asc("A") + (Asc(char) - Asc("A") + offset) Mod 26
Caesar = Caesar & Chr(char)
ElseIf char >= "a" And char <= "z" Then
char = Asc("a") + (Asc(char) - Asc("a") + offset) Mod 26
Caesar = Caesar & Chr(char)
Else
Caesar = Caesar & char
End If
Next
End Function

inputbox "密文:","凯撒密码",Caesar("i love you", 5)
'"i love you" 是要加密的字符串；5是字母的位移数

Input=Inputbox("输入字符加解密","反字母表加解密")
If Input="" Then Wscript.quit
For i = 1 To Len(LCase(Input))
        If Mid(LCase(Input), i, 1) = "a" Then Output = Output & "z"
        If Mid(LCase(Input), i, 1) = "b" Then Output = Output & "y"
        If Mid(LCase(Input), i, 1) = "c" Then Output = Output & "x"
        If Mid(LCase(Input), i, 1) = "d" Then Output = Output & "w"
        If Mid(LCase(Input), i, 1) = "e" Then Output = Output & "v"
        If Mid(LCase(Input), i, 1) = "f" Then Output = Output & "u"
        If Mid(LCase(Input), i, 1) = "g" Then Output = Output & "t"
        If Mid(LCase(Input), i, 1) = "h" Then Output = Output & "s"
        If Mid(LCase(Input), i, 1) = "i" Then Output = Output & "r"
        If Mid(LCase(Input), i, 1) = "j" Then Output = Output & "q"
        If Mid(LCase(Input), i, 1) = "k" Then Output = Output & "p"
        If Mid(LCase(Input), i, 1) = "l" Then Output = Output & "o"
        If Mid(LCase(Input), i, 1) = "m" Then Output = Output & "n"
        If Mid(LCase(Input), i, 1) = "n" Then Output = Output & "m"
        If Mid(LCase(Input), i, 1) = "o" Then Output = Output & "l"
        If Mid(LCase(Input), i, 1) = "p" Then Output = Output & "k"
        If Mid(LCase(Input), i, 1) = "q" Then Output = Output & "j"
        If Mid(LCase(Input), i, 1) = "r" Then Output = Output & "i"
        If Mid(LCase(Input), i, 1) = "s" Then Output = Output & "h"
        If Mid(LCase(Input), i, 1) = "t" Then Output = Output & "g"
        If Mid(LCase(Input), i, 1) = "u" Then Output = Output & "f"
        If Mid(LCase(Input), i, 1) = "v" Then Output = Output & "e"
        If Mid(LCase(Input), i, 1) = "w" Then Output = Output & "d"
        If Mid(LCase(Input), i, 1) = "x" Then Output = Output & "c"
        If Mid(LCase(Input), i, 1) = "y" Then Output = Output & "b"
        If Mid(LCase(Input), i, 1) = "z" Then Output = Output & "a"
        If Mid(LCase(Input), i, 1) = " " Then Output = Output & " "
    Next
Msgbox Output,0,"反字母表加解密"