Kriptografi

• 
•  
• Public Class Form1
      Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
          plainteks.Text = ""
          chiperteks.Text = ""
      End Sub
      Private Sub Btnenkript_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnenkript.Click
          Dim jumlah As Double = Len(plainteks.Text)
          Dim x As String
          Dim xkalimat As String = ""
          Dim i As Double
          Dim bil As Integer
          For i = 1 To jumlah
              x = Mid(plainteks.Text, i, 1)
              bil = Asc(x) + 3
              x = Chr(bil)
              xkalimat = xkalimat + x
          Next i
          chiperteks.Text = xkalimat
      End Sub
      Private Sub Btnerase_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnerase.Click
          chiperteks.Text = ""
          plainteks.Text = ""
      End Sub
  End Class
   
•  Caesar

Public Class Form2

    Private Sub Btnenkrip_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnenkrip.Click
        Dim x As String
        Dim bil As Integer
        Chiperteks.Text = ""
        For i = 1 To Len(plainteks.Text)
            x = Microsoft.VisualBasic.Mid(Plainteks.Text, i, 1)
            bil = Asc(x)
            bil = bil + 3 Mod 26
            x = Chr(bil)
            Chiperteks.Text = Chiperteks.Text & x
        Next
    End Sub

    Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        chiperteks.Text = ""
        plainteks.Text = ""

    End Sub

    Private Sub Btndeskrip_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btndeskrip.Click
        Dim x As String
        Dim bil As Integer
        chiperteks.Text = ""
        For i = 1 To Len(plainteks.Text)
            x = Microsoft.VisualBasic.Mid(plainteks.Text, i, 1)
            bil = Asc(x)
            bil = bil - 3 Mod 26
            x = Chr(bil)
            chiperteks.Text = chiperteks.Text & x
        Next

    End Sub
End Class

• Vernam
• Public Class Form3
  
      Private Sub Form3_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
          plainteks.Text = ""
          kunci.Text = ""
          chiperteks.Text = ""
  
      End Sub
  
      Private Sub Btnenkript_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnenkript.Click
          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 sPlain As String = ""
          Dim nEnc As Integer
          j = 0
          sKata = plainteks.Text
          jum = Len(sKata)
          sKey = kunci.Text
          For i = 1 To jum
              If j = Len(sKey) Then
                  j = 1
              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)
  
              sPlain = sPlain & Chr((nEnc) + 65)
          Next i
          chiperteks.Text = sPlain
  
  
      End Sub
  
      Private Sub plainteks_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles plainteks.KeyPress
          e.KeyChar = UCase(e.KeyChar)
          Dim tombol As Integer = Asc(e.KeyChar)
          If Not (((tombol >= 65) And (tombol <= 90)) Or (tombol = 8)) Then
              e.Handled = True
          End If
  
  
      End Sub
  
      Private Sub kunci_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles kunci.KeyPress
          e.KeyChar = UCase(e.KeyChar)
          Dim tombol As Integer = Asc(e.KeyChar)
          If Not (((tombol >= 65) And (tombol <= 90)) Or (tombol = 8)) Then
              e.Handled = True
          End If
  
      End Sub
  End Class

• Vigenere

Public Class Form4

    Private Sub BtnProses_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnProses.Click
        chiperteks.Text = Enkripsi(plainteks.Text, kunci.Text)
    End Sub
    Function enkripsi(ByVal teks As String, ByVal kunci As String) As String
        Dim a As Integer
        Dim b As Integer
        Dim sKey As String
        Dim nKata As Integer
        Dim nKunci As Integer
        Dim sKata As String
        Dim sPlain As String
        Dim nEnc As Integer
        a = 0
        b = Len(teks)
        sPlain = ""
        sKey = kunci
        sKata = teks
        For i = 1 To b
            If a = Len(sKey) Then
                a = 1
            Else
                a = a + 1
            End If
            nKata = Asc(Mid(sKata, i, 1))
            nKunci = Asc(Mid(sKey, a, 1))
            nEnc = ((nKata + nKunci) Mod 256)
            sPlain = sPlain & Chr((nEnc))
        Next i
        enkripsi = sPlain
    End Function


    Private Sub Btnhapus_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnhapus.Click
        plainteks.Text = ""
        chiperteks.Text = ""
        kunci.Text = ""

    End Sub

    Private Sub Btnkeluar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnkeluar.Click
        Close()
    End Sub
End Class

• Gronsfeld
• Public Class Form5
•  Private Sub Btnenkript_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnenkript.Click
          Dim x As String
          Dim CI As Integer
          chiperteks.Text = ""
          For i = 1 To Len(plainteks.Text)
              x = Microsoft.VisualBasic.Mid(plainteks.Text, i, 1)
              CI = Asc(x)
              CI = (plainteks.Text + kunci.Text) Mod 26
              x = Chr(CI)
              chiperteks.Text = chiperteks.Text & x
          Next
          chiperteks.Text = enkripsi(plainteks.Text, kunci.Text)
      End Sub
  
      Private Sub Btndeskript_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btndeskript.Click
          Dim x As String
          Dim CI As Integer
          Dim KI As Integer
          Dim PI As Integer
          chiperteks.Text = ""
          For i = 1 To Len(plainteks.Text)
              x = Microsoft.VisualBasic.Mid(plainteks.Text, i, 1)
              PI = Asc(x)
              PI = (CI - KI) Mod 26
              x = Chr(PI)
              chiperteks.Text = chiperteks.Text & x
          Next
  
      End Sub
      Function enkripsi(ByVal teks As String, ByVal kunci As String) As String
          Dim a As Integer
          Dim b As Integer
          Dim sKey As String
          Dim nKata As Integer
          Dim nKunci As Integer
          Dim sKata As String
          Dim sPlain As String
          Dim nEnc As Integer
          a = 0
          b = Len(teks)
          sPlain = ""
          sKey = kunci
          sKata = teks
          For i = 1 To b
              If a = Len(sKey) Then
                  a = 1
              Else
                  a = a + 1
              End If
              nKata = Asc(Mid(sKata, i, 1))
              nKunci = Asc(Mid(sKey, a, 1))
              nEnc = ((nKata + nKunci) Mod 26)
              sPlain = sPlain & Chr((nEnc))
          Next i
          enkripsi = sPlain
      End Function
  
      Private Sub Form5_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
          chiperteks.Text = ""
          plainteks.Text = ""
          kunci.Text = ""
  
      End Sub
  End Class

 

Link Tugas TI-P1104