Encryption Algorithms

[chemicalNova]

Howdy all,

I'm wondering if there are any tutorials anyone has come across regarding advanced text encryption. I want to see how uncrackable I can get a small text file.

Hopefully I can possibly transpose this onto pictures aswell.

Thanks in advance,

chem

[dglienna]

I like to use Capicom, which Microsoft released. It encrypts differently each time, based on the time. It decrypts perfectly! You can google it.

I haven't encrypted files, but I'm pretty sure it would be possible. I have only encrypt text strings.

[chemicalNova]

I really only want to encrypt text strings (in turn, the text files). Can you provide any articles which have some algorithms or theory behind text encryption?

chem

[dglienna]

You mean other than Capicom? This is something that I have also used.

Dim ff As Integer
Public st As String
 
Private Sub Form_Load()
    ff = FreeFile
    Dim strBuff As String
    ff = FreeFile
    Open App.Path & "/site.txt" For Input As #ff
    Do Until EOF(ff)
       Line Input #ff, strBuff
    Loop
    Close #ff
    Text1.Text = RC4ED(strBuff, "837ufhjjkddQR13%^&*&@#$&9ASFewFDAAW!%9367")
    Call WriteFile
End Sub
 
Sub WriteFile()
 ff = FreeFile
    Open App.Path & "\site.txt" For Output As #ff
        Print #ff, Text1.Text ' <-- Might need to use Write # to add quotes
    Close #ff
End Sub
 
Function RC4ED(InString As String, password As String) As String
 
    Dim S(0 To 255) As Integer
    Dim K(0 To 255) As Integer
    Dim I As Integer, j As Integer, tmp As Integer
    Dim t As Integer
    Dim outstring As String
 
 
    For tmp = 0 To 255
        S(tmp) = tmp
        K(tmp) = Asc(Mid(password, 1 + (tmp Mod Len(password)), 1))
    Next
 
 
    For I = 0 To 255
        j = (j + S(I) + K(I)) Mod 256
        Swap S(I), S(j)
    Next
 
    I = 0
    j = 0
    outstring = ""
 
 
    For tmp = 1 To Len(InString)
        I = (I + 1) Mod 256
        j = (j + S(I)) Mod 256
        Swap S(I), S(j)
        t = (S(I) + S(j)) Mod 256
        outstring = outstring & Chr((mXor(S(t), Asc(Mid(InString, tmp, 1)))))
    Next
 
    RC4ED = outstring
End Function
 
 
Function mXor(I As Integer, j As Integer) As Integer
 
 
    If I = j Then
        mXor = j
    Else
        mXor = I Xor j
    End If
 
End Function
 
 
Sub Swap(ByRef a As Integer, ByRef b As Integer)
 
    Dim t As Integer
    t = a
    a = b
    b = t
End Sub

Here's a link. Run the program twice. First time encrypts, second time decrypts.
http://vbforums.com/attachment.php?attachmentid=37573

[chemicalNova]

Thanks for that DG, can start to fiddle with some things now

chem

[StrangerInBeijing]

I did not use it for a while, but you got encryption build into .Net

Check this out for a starter: RSA in VB.NET

[wossname]

VS.net has a whole namespace full of encryption classes. Gives you full control of everything. You won't get any much more uncrackable than that.

[chemicalNova]

I kinda want to see how far I can go with my own. I also hoped to make a voice recognition decryption. The person says the password, and the text is decrypted. I might actually look alot deeper than I originally was for this..

Ta though

chem

[StrangerInBeijing]

I kinda want to see how far I can go with my own. I also hoped to make a voice recognition decryption. The person says the password, and the text is decrypted. I might actually look alot deeper than I originally was for this..

Ta though

chem

huh? whatever you are smoking, I want some too!