1)将该字符ASCI码转换成对应8位二进制;
2)将对应8位二进制数进行按位取反(1变0;0变1);
3)将产生的8位二进制数循环左移3次;
4)最后产生的8位二进制数转换成对应的十六进制数。
例如:明文大写字母“A”通过上述算法加密算法加密后生成的密文是“F5”,在文本框Text1中输入明文,单击“生成密文”按钮Command1,加密后生成的密文显示在文本框Text2中。
Function btoh(m As String)As String ‘将4位二进制数转换成对应的十六进制数
Dim s As Integer, i As Integer, str As String
str ="0123456789ABCDEF": s=0
For i=1 To 4
s=s*2+ Val(Mid(m, i, 1))
Next i
①
End Function
Private Sub Command1_Click()
Dim ans As String, s As String, ch As String, ret As String
Dim i As Integer, asc1 As Integer, n As Integer
②
ans=" "
For i = 1 To Len(s)
ch =Mid(s, i, 1) ‘取出第i个字符存入变量ch
asc1=Asc(ch)
ret" "
For m =1 To 8 ‘完成加密步骤1)和步骤2)
n=(asc1+1)mod 2
ret =n & ret
③
Next m
ret = Mid(ret, 4, 5)+ Mid(ret, 1, 3) ‘完成加密步骤3)和步骤4)
s1=btoh(Mid(ret, 1, 4))
s2 =btoh(Mid(ret, 5, 4))
ans =ans & s1 & s2 ‘将第i个加密后的字符添加到变量ans的末尾
Next i
Text2.Text = ans
End Sub
① ② ③