Diffie-Hellmann Key Exchange Protocol

Diffie Hellmann Key exchange Protocol code in visual basic.
step 1: Design the form1 and form2
step 2: paste the code and run the application.

Form1.frm

Private Sub Command1_Click()

Form1.Hide

MsgBox ("Click the form to Enter values")

Form2.Show

End Sub

Form2.frm

Dim a, c, b, q, xa, xb, ya, yb, k1, k2, e, f, g, h, i As Double

Private Sub Command1_Click()

xa = Val(Text1.Text)

g = xa

a = Val(Text4.Text)

q = Val(Text3.Text)

ya = 1

e = a Mod q

Do

If (xa Mod 2) <> 0 Then

ya = (ya * e) Mod q

End If

xa = Int(xa / 2)

e = (e * e) Mod q

Loop Until xa = 0

Text5.Visible = True

Text5.Text = ya

Command2.Visible = True

End Sub

Private Sub Command2_Click()

xb = Val(Text2.Text)

h = xb

yb = 1

f = a Mod q

Do

If (xb Mod 2) <> 0 Then

yb = (yb * f) Mod q

End If

xb = Int(xb / 2)

f = (f * f) Mod q

Loop Until xb = 0

Text6.Visible = True

Text6.Text = yb

Command3.Visible = True

End Sub

Private Sub Command3_Click()

k1 = 1

c = yb Mod q

Do

If (g Mod 2) <> 0 Then

k1 = (k1 * c) Mod q

End If

g = Int(g / 2)

c = (c * c) Mod q

Loop Until g = 0

'k1 = (yb ^ xa) Mod q

k2 = 1

d = ya Mod q

Do

If (h Mod 2) <> 0 Then

k2 = (k2 * d) Mod q

End If

h = Int(h / 2)

d = (d * d) Mod q

Loop Until h = 0

'k2 = (ya ^ xb) Mod q

If k1 = k2 Then

MsgBox ("K1 = " & k1 & vbCrLf & "K2 = " & k2)

Text7.Visible = True

Text7.Text = k1

Else

End

End If

Command5.Visible = True

End Sub

Private Sub Command4_Click()

End

End Sub

Private Sub Command5_Click()

Form2.Hide

Form1.Show

Text1.Text = " "

Text2.Text = " "

Text3.Text = " "

Text4.Text = " "

Text5.Text = " "

Text6.Text = " "

Text7.Text = " "

Text1.Visible = False

Text2.Visible = False

Text3.Visible = False

Text4.Visible = False

Text5.Visible = False

Text6.Visible = False

Text7.Visible = False

Command1.Visible = False

Command2.Visible = False

Command3.Visible = False

Command5.Visible = False

End Sub

Private Sub Form_Click()

Text1.Visible = True

Text2.Visible = True

Text3.Visible = True

Text4.Visible = True

Command1.Visible = True

End Sub

Private Sub Form_Load()

Text1.Visible = False

Text2.Visible = False

Text3.Visible = False

Text4.Visible = False

Text5.Visible = False

Text6.Visible = False

Text7.Visible = False

Command1.Visible = False

Command2.Visible = False

Command3.Visible = False

Command5.Visible = False

End Sub