UWLDIFV CV MV ORA MWTCWHI CVKQPXSVZ (code RIZ)
Sub crypter()
alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Phrase = UCase(Cells(1, 2).Value)
Cle = UCase(Cells(2, 2).Value)
LenPhrase = Len(Phrase)
LenCle = Len(Cle)
code = ""
For i = 1 To LenPhrase
If Mid(Phrase, i, 1) <> " " Then
lettre1 = Mid(Phrase, i, 1)
pos1 = InStr(1, alpha, lettre1)
lettre2 = Mid(Cle, (i - 1) Mod LenCle + 1, 1)
pos2 = InStr(1, alpha, lettre2)
code = code & Mid(alpha, (pos1 + pos2 - 2) Mod 26 + 1, 1)
Else
code = code & " "
End If
Next
Cells(3, 2).Value = code
End Sub
Sub decrypter()
alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Phrase = UCase(Cells(3, 2).Value)
Cle = UCase(Cells(2, 2).Value)
LenPhrase = Len(Phrase)
LenCle = Len(Cle)
code = ""
For i = 1 To LenPhrase
If Mid(Phrase, i, 1) <> " " Then
lettre1 = Mid(Phrase, i, 1)
pos1 = InStr(1, alpha, lettre1)
lettre2 = Mid(Cle, (i - 1) Mod LenCle + 1, 1)
pos2 = InStr(1, alpha, lettre2)
code = code & Mid(alpha, pos1 - pos2 + 1 + IIf(pos1 - pos2 + 1 < 0, 26, 0), 1)
Else
code = code & " "
End If
Next
Cells(4, 2).Value = code
End Sub