Public Class Form1
Private Sub VigenToolStripMenuItem_Click(ByVal sender As
System.Object, ByVal e As
System.EventArgs) Handles
VigenToolStripMenuItem.Click
Form2.MdiParent = Me
Form2.Show()
End Sub
Private Sub CaesarChiperToolStripMenuItem_Click(ByVal sender As
System.Object, ByVal e As
System.EventArgs) Handles
CaesarChiperToolStripMenuItem.Click
Form3.MdiParent = Me
Form3.Show()
End Sub
Private Sub GransfeldChiperToolStripMenuItem_Click(ByVal sender As
System.Object, ByVal e As
System.EventArgs) Handles
GransfeldChiperToolStripMenuItem.Click
Form4.MdiParent = Me
Form4.Show()
End Sub
Private Sub VernamChiperToolStripMenuItem_Click(ByVal sender As
System.Object, ByVal e As
System.EventArgs) Handles
VernamChiperToolStripMenuItem.Click
Form5.MdiParent = Me
Form5.Show()
End Sub
Private Sub DesChiperToolStripMenuItem_Click(ByVal sender As
System.Object, ByVal e As
System.EventArgs) Handles DesChiperToolStripMenuItem.Click
Form6.MdiParent = Me
Form6.Show()
End Sub
Private Sub RC4ToolStripMenuItem_Click(ByVal sender As
System.Object, ByVal e As
System.EventArgs) Handles
RC4ToolStripMenuItem.Click
Form7.MdiParent = Me
Form7.Show()
End Sub
Private Sub KeluarToolStripMenuItem_Click(ByVal sender As
System.Object, ByVal e As
System.EventArgs) Handles
KeluarToolStripMenuItem.Click
End
End Sub
End Class
Caesar Chiper
Public Class Form2
Private Sub btnEnkripsi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEnkripsi.Click
Dim x As String
Dim bil As Integer
Cipher.Text = ""
For i = 1 To Len(Plain.Text)
x = Microsoft.VisualBasic.Mid(Plain.Text, i, 1)
bil = Asc(x)
bil = bil + 3
x = Chr(bil)
Cipher.Text = Cipher.Text & x
Next
End Sub
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Plain.Text = ""
Cipher.Text = ""
End Sub
End Class
Gransfeld Chiper
Vernam Chiper
contoh:
Saya memiliki sebuah plaintext yaitu RUSDI dan memiliki sebuah kunci yaitu
CRASH (ingat panjang kunci harus sama dengan plaintext dan sebaiknya tidak
ada karakter yang diulang).
Pertama kita harus mendapatkan kode ASCII dari plaintext kemudian diubah
ke bentuk biner
kode
Setelah itu masing-masing karakter di XOR-kan dengan Key
R = 0101 0010 U = 0101 0101 S = 0101 0011 D = 0100 0100 I = 0100 1001
C = 0100 0011 R = 0101 0010 A = 0100 0001 S = 0101 0011 H = 0100 1000
XOR -------------------------------------------------------------------------
Cipher: 0001 0001 0000 0111 0001 0010 0001 0111 0000 0001
-----------------------------------------------------------------------------
ASCII : Ctrl-Q Ctrl-G Ctrl-R Ctrl-W Ctrl-A
Proses dekripsi pesan juga melakukan operasi yang sama yaitu XOR antara Cipher
dengan key.
Cipher: 0001 0001 0000 0111 0001 0010 0001 0111 0000 0001
Key: 0100 0011 0101 0010 0100 0001 0101 0011 0100 1000
XOR -------------------------------------------------------------------------
Plain : 0101 0010 0101 0101 0101 0011 0100 0100 0100 1001
-----------------------------------------------------------------------------
code
Option Explicit
Private RByte() As Variant
Private Sub cmdDecrypt_Click()
TxtPlain.Text = crypt(TxtCipher.Text, False)
End Sub
Private Sub cmdEncrypt_Click()
TxtCipher.Text = crypt(TxtPlain.Text, True)
End Sub
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
FrmAbout.Show
End Sub
Private Function crypt(strInput As String, _
ByVal bEncrypt As Boolean) As String
Dim I As Long
Dim NewAsc As Long
Dim keypos As Long
GetKey TxtKey
For I = 1 To Len(strInput)
If bEncrypt Then
NewAsc = Asc(Mid$(strInput, I, 1)) + RByte(keypos)
Else
NewAsc = Asc(Mid$(strInput, I, 1)) - RByte(keypos)
End If
Do While NewAsc < newasc =" NewAsc"> 255
NewAsc = NewAsc - 255
Loop
Mid$(strInput, I, 1) = Chr$(NewAsc)
keypos = keypos + 1
If keypos > UBound(RByte) Then
keypos = 0
End If
Next I
crypt = strInput
End Function
Private Sub GetKey(StrA As String)
Dim I As Long
If Len(StrA) Then
ReDim RByte(Len(StrA) - 1) As Variant
For I = 1 To Len(StrA)
RByte(I - 1) = Asc(Mid$(StrA, I, 1))
Next I
End If
End Sub
Vigenere Chiper
Public
Class Form2
Private Sub btnProses_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnProses.Click
Chipertext.Text = Enkripsi(Plaintext.Text, Kunci.Text)
End Sub
Function Enkripsi(ByVal Teks As String, ByVal Kunci As String) As String
Dim j As Integer
Dim jum As Integer
Dim sKey As String
Dim nKata As Integer
Dim nKunci As Integer
Dim sKata As String
Dim sPlain As String
Dim nEnc As Integer
j = 0
jum = Len(Teks)
sPlain = ""
sKey = Kunci
sKata = Teks
For i = 1 To jum
If j = Len(sKey) Then
j = 1
Else
j = j + 1
End If
nKata = Asc(Mid(sKata, i, 1))
nKunci = Asc(Mid(sKey, j, 1))
nEnc = ((nKata + nKunci) Mod 256)
sPlain = sPlain & Chr((nEnc))
Next i
Enkripsi = sPlain
End Function
End Class
Private Sub btnProses_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnProses.Click
Chipertext.Text = Enkripsi(Plaintext.Text, Kunci.Text)
End Sub
Function Enkripsi(ByVal Teks As String, ByVal Kunci As String) As String
Dim j As Integer
Dim jum As Integer
Dim sKey As String
Dim nKata As Integer
Dim nKunci As Integer
Dim sKata As String
Dim sPlain As String
Dim nEnc As Integer
j = 0
jum = Len(Teks)
sPlain = ""
sKey = Kunci
sKata = Teks
For i = 1 To jum
If j = Len(sKey) Then
j = 1
Else
j = j + 1
End If
nKata = Asc(Mid(sKata, i, 1))
nKunci = Asc(Mid(sKey, j, 1))
nEnc = ((nKata + nKunci) Mod 256)
sPlain = sPlain & Chr((nEnc))
Next i
Enkripsi = sPlain
End Function
End Class
Des Chiper
RC4
Public Function RC4(ByVal Expression As String, ByVal Password As String) As String
On Error Resume Next
Dim RB(0 To 255) As Integer, X As Long, Y As Long, Z As Long, Key() As Byte, ByteArray() As Byte, Temp As Byte
If Len(Password) = 0 Then
Exit Function
End If
If Len(Expression) = 0 Then
Exit Function
End If
If Len(Password) > 256 Then
Key() = StrConv(Left$(Password, 256), vbFromUnicode)
Else
Key() = StrConv(Password, vbFromUnicode)
End If
For X = 0 To 255
RB(X) = X
Next X
X = 0
Y = 0
Z = 0
For X = 0 To 255
Y = (Y + RB(X) + Key(X Mod Len(Password))) Mod 256
Temp = RB(X)
RB(X) = RB(Y)
RB(Y) = Temp
Next X
X = 0
Y = 0
Z = 0
ByteArray() = StrConv(Expression, vbFromUnicode)
For X = 0 To Len(Expression)
Y = (Y + 1) Mod 256
Z = (Z + RB(Y)) Mod 256
Temp = RB(Y)
RB(Y) = RB(Z)
RB(Z) = Temp
ByteArray(X) = ByteArray(X) Xor (RB((RB(Y) + RB(Z)) Mod 256))
Next X
RC4 = StrConv(ByteArray, vbUnicode)
End Function
