Kriptogfrafi Vigenere

Public Class Form1
    Function Enkripsi(ByVal text As String, ByVal kunci As String) As String

        Dim j As Integer
        Dim jum As Integer
        Dim skey As String
        Dim nkata As Integer
        Dim nkunci As Integer
        Dim skata As String
        Dim skunci As String
        Dim nEnc As Integer
        Dim splain As String
        j = 0

        jum = Len(text)
        splain = ""
        skey = kunci
        skata = text
        For i = 1 To jum
            If j = Len(skey) Then
            Else
                j = j + 1
            End If

            nkata = Asc(Mid(skata, i, 1)) - 65
            nkunci = Asc(Mid(skey, j, 1)) - 65
            nEnc = ((nkata + nkunci) Mod 26) + 65
            splain = splain & Chr(nEnc)
        Next i
        Enkripsi = splain
    End Function

    Private Sub Btnproses_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnproses.Click
        chipertext.Text = Enkripsi(plaintext.Text, kunci.Text)

    End Sub
End Class