Public Function VigenereCode(Original As String, Passwort As String) As String
    Dim i As Long
    Dim aktpos As Long
    Dim bAkt As Byte
    Dim bCode As Byte
 
    VigenereCode = ""
 
    <font color=green>' Passwort auf die Länge des Klartextes bringen</font>
    <font color=green>' Dazu wird z.B. aus "Geheim" dann _
      "GeheimGeheimGehe...."</font>
    aktpos = 1
    For i = Len(Passwort) + 1 To Len(Original)
        Passwort = Passwort & Mid(Passwort, aktpos, 1)
        aktpos = aktpos + 1
        If aktpos > Len(Passwort) Then aktpos = 1
    Next i
 
    For i = 1 To Len(Original)
        bAkt = Asc(Mid(Original, i, 1))
        bCode = Asc(Mid(Passwort, i, 1))
 
        VigenereCode = VigenereCode & Chr(bAkt Xor bCode)
    Next i
 
End Function