Jump to content
Sign in to follow this  
pixartist

Help me speed up my encryption

Recommended Posts

pixartist

Hi, i built a little symmetric encryption algorithm. I don't know too much about encryption, but i tried to get as asymetric results as possible irrespective of the symmetry of the encrypted file, in other words i tried to get no patterns in the result even though the input may have very simple patterns (eg.: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...)

the encryption key is scrambled for every iteration which makes the algorithm VERY slow.

1. i wanna know what you think of the algorithm

2. i wanna know if you have any ideas to do this faster in autoit

#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
#include <EditConstants.au3>
#include <StaticConstants.au3>
#Include <GuiEdit.au3>

#Region ### START Koda GUI section ### Form=
$Form1 = GUICreate("pixcrypt", 315, 126, 193, 115)
$key = GUICtrlCreateInput("", 128, 8, 177, 21)
$Label1 = GUICtrlCreateLabel("Key:", 96, 16, 25, 17)
$Button1 = GUICtrlCreateButton("En/Decrypt", 8, 8, 75, 25, 0)
$Label2 = GUICtrlCreateLabel("->", 8, 64, 13, 17)
$Input2 = GUICtrlCreateInput("", 8, 40, 297, 21)
GUICtrlSetState(-1, $GUI_DISABLE)
$Input3 = GUICtrlCreateInput("", 8, 80, 297, 21)
GUICtrlSetState(-1, $GUI_DISABLE)

$Progress1 = GUICtrlCreateProgress(8, 104, 302, 16)
GUISetState(@SW_SHOW)
#EndRegion ### END Koda GUI section ###
$fsize = 0
While 1
    $nMsg = GUIGetMsg()
    Switch $nMsg
        Case $GUI_EVENT_CLOSE
            Exit
        Case $Button1
            
            $f = FileOpenDialog("Choose File",@ScriptDir, "Any (*.*)", 1)
            if $f then
                
                $s = FileSaveDialog( "Save result to", @ScriptDir, "Any (*.*)", 18)
                if $s Then
                    GUICtrlSetData($Input2,$f)
                    GUICtrlSetData($Input3,$s)
                    $fi= FileOpen ( $s, 18 )
                    If $fi = -1 Then
                        MsgBox(0, "Error", "Unable to open file.")
                        Exit
                    EndIf
                    $timerstart = TimerInit()
                    $enc = Binary(encrypt($f,  GUICtrlRead($key)))
                    GUICtrlSetData($Progress1, 0)
                    $timetaken = TimerDiff($timerstart)
                    MsgBox(0,"Done", "Process took "& (floor($timetaken/100)/10) &" seconds for "& $fsize &" bytes." & @CRLF & $fsize/$timetaken & " bytes per ms")
                    FileWrite($fi, $enc)
                    FileClose($fi)
                EndIf
                
            EndIf
    EndSwitch
WEnd


Func ArraySwap($array, $p1, $p2)
    $tval = $array[$p1];
    $array[$p1] = $array[$p2]
    $array[$p2] = $tval
    Return $array
EndFunc


Func encrypt($file, $key)
    
    Dim $res; = Binary(0);
    $t = 0
    $keyarr = StringSplit($key, "")
    Dim $filedata  = Binary(0);
    Dim $erg  = Binary(0);
    $filedata = FileRead(FileOpen ( $file, 16 ))
    $filelen = BinaryLen( $filedata )
    $keytstart2 = Ceiling($keyarr[0]/2)
    $keytbend2 = Floor($keyarr[0]/2)
    $tlen2 = ($keyarr[0]-$keytstart2)+1;
    $fsize = $filelen
    for $i = 0 to $filelen-1 ;iterate every singly byte in the file
        GUICtrlSetData($Progress1, (100/$filelen)*$i)
        For $im = 0 to $keytbend2-1 ;iterate through half the key chars (floored)
            $val = Asc($keyarr[$im+1])+$im+$i
            if $tlen2 > $val Then ;SCRAMBLE!
                $spos = Mod($tlen2, $val)
            Else
                $spos = Mod($val, $tlen2)
            EndIf
            
            $keyarr = ArraySwap($keyarr, $im+1, $keytstart2+$spos);swapping char positions, yes swapping bytes would be nice, but i'm lazy
        Next
        $kstr = ""
        For $im = 1 to $keyarr[0]
            $kstr &= $keyarr[$im] ;imploding the new key
        Next
        
        $keybinary = StringToBinary($kstr);
        $keylen = BinaryLen($keybinary);

        $c_keybyte = Mod($i, $keylen)

        
        ;keykeykeykeykeyke 
        ;bytes in the file
        $erg = BitXOR(BinaryMid($keybinary, $c_keybyte+1, 1),BinaryMid($filedata, $i+1, 1)) ;simple xor with bytes in the key and bytes in the file

        if $i > 1 Then
            $c_keybytePrior = Mod($i-1, $keylen)
            
            $erg = BitXOR(BinaryMid($keybinary, $c_keybytePrior+1, 1), $erg) ;xoring with the previous byte in the key
        EndIf
        FileClose($file)
        $res = $res & Hex($erg,2)
        
    Next

    return Binary("0x"& $res)
EndFunc

thanks

Share this post


Link to post
Share on other sites
Pain

Take a look at SkinnyWhiteGuy's Crypto Suite and you will see real Blowfish and Rijndael algorithms. Rijndael is really fast for being in AutoIt.

I believe the S-Box is one way to make it faster, if you don't know about S-Box you can read more here http://en.wikipedia.org/wiki/Rijndael_S-box and here http://en.wikipedia.org/wiki/Substitution_box

Also try put as many things as possible in loops and arrays to make it faster.

Share this post


Link to post
Share on other sites
pixartist

Take a look at SkinnyWhiteGuy's Crypto Suite and you will see real Blowfish and Rijndael algorithms. Rijndael is really fast for being in AutoIt.

I believe the S-Box is one way to make it faster, if you don't know about S-Box you can read more here http://en.wikipedia.org/wiki/Rijndael_S-box and here http://en.wikipedia.org/wiki/Substitution_box

Also try put as many things as possible in loops and arrays to make it faster.

well, i dont wanna use someone elses algorithm, but my own :)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.