Implementasi dan Analisis Kriptografi Hybrid Algoritma FEAL dan Algoritma ElGamal Dalam Pengamanan File Teks

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BIODATA MAHASISWA

A. DATA MAHASISWA

1. Nama Lengkap : Syabrul Majid

2. Tempat dan Tanggal Lahir : Batang Hari, 26 Maret 1992

3. Agama : Islam

4. Jenis Kelamin : Laki-laki

5. NIM : 131421058

6. E-mail : majidadnese@gmail.com

7. Golongan Darah : O

8. Anak ke : 2 (dua) dari 4 (Empat) bersaudara 9. Departemen/Program Studi : S1 Ilmu Komputer

10.Alamat Rumah : Jl. Dr.Mansyur No 70 Medan 11.No. Telepon Rumah/HP : 085362050610

12.Asal SMA/SMK/MA : SMA Negeri 1 Danau Kembar 13.Tahun Lulus SMA/SMK/MA : 2010

14.Kodya/Kabupaten : Solok, Sumatera Barat

15.Alamat Sekolah : Jl. Panorama danau Kembar, Solok

16.Nilai NEM** : 48,00

3. Tempat dan Tanggal Lahir

- Ayah : Syahril, 07 September 1964

6. Pendidikan Terakhir

- Ayah : SMP

- Ibu : SD

7. Jumlah Tanggungan Orangtua : 4 (Empat) Orang

8. Alamat Kantor : -

9. Alamat Rumah Orangtua : Jl. Batang Hari, Kecamatan Lembah Gumanti, Alahan Panjang, Kabupaten Solok, Sumatera Barat

10. No. Telepon/HP : 087868606468

Medan, 06 Januari 2016 Hormat Saya,

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LISTING PROGRAM

Index.php

<?php

session_start();

include "elgamal.php";

require 'nor1.class.php'; require 'norctr.class.php';

$timer = microtime(true);

$pw = empty($_POST['pw']) ? '' : $_POST['pw']; $pt = empty($_POST['pt']) ? '' : $_POST['pt'];

$cipher = empty($_POST['cipher']) ? '' :

$_POST['cipher'];

$plain = empty($_POST['plain']) ? '' :

$_POST['plain'];

$encr = empty($_POST['encr']) ? $cipher :

FEALCtr::encrypt($pt, $pw, 256) ;

$decr = empty($_POST['decr']) ? $plain :

FEALCtr::decrypt($cipher, $pw, 256);

$enkripsi = new

elgamal($_SESSION['p'],$_SESSION['g'],$_SESSION['x'],$_SE SSION['y'],$_SESSION['k']);

$dekripsi = new

elgamal($_SESSION['p'],$_SESSION['g'],$_SESSION['x'],$_SE SSION['y'],$_SESSION['k']);

$cipherkey = empty($_POST['cipherkey']) ? '' : $_POST['cipherkey'];

$plainkey = empty($_POST['plainkey']) ? '' : $_POST['plainkey'];

$chippertextkey = empty($_POST['enkey']) ?

$cipherkey : $enkripsi->_enkripsi($plainkey) ;

$plaintextkey = empty($_POST['dekey']) ? $pw :

$enkripsi->_dekripsi($cipherkey) ;

if(!isset($_SESSION['username'])) { header('location:login.php'); }

else { $username = $_SESSION['username']; } require_once("koneksi.php");

$query = mysql_query("SELECT * FROM user WHERE username = '$username'");

$hasil = mysql_fetch_array($query); ?>

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<head>

content="IE=edge">

content="width=device-width, initial-scale=1">

<title>IMPLEMENTASI DAN ANALISIS KRIPTOGRAFI HYBRID ALGORITMA FEAL DAN ALGORITMA ELGAMAL DALAM PENGAMANAN FILE TEKS</title>

rel="stylesheet" />

</head> <header>

<div class="col-md-6 col-sm-6 col-xs-6 text-right

navicon">

<div class="lg-container4">Proccess time : <?=

round(microtime(true) - $timer, 3) ?>s</div></p>

<a id="trigger-overlay" class="nav_slide_button

nav-toggle"

href="../template/index.php"><span></span></a></div> </div>

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var aMenu = document.getElementById(aMenu);

aMenu.style.display = (aMenu.style.display == "block") ? "none" : "block";

}

</script>

{

if (document.NamaForm.NamaSelection.value ==

"muncul"){document.getElementById('DivTampil').style.disp lay="inline"}

"muncul"){document.getElementById('DivTampil2').style.dis play="none"}

"hilang"){document.getElementById('DivTampil').style.disp lay="none"}

"hilang"){document.getElementById('DivTampil2').style.dis play="inline"}

}

</script>

<h3><b>File and Text Encryption using FEAL </b></h3>

<tr>

<td>Choose   : </td>

<select style="width:500px" name='NamaSelection'

onchange='DisplayShowHide()'>

</select> </form> <br> </table>

<table class="fixed-layout"

style="border-collapse:collapse;">

<form action="file-processor.php" method="post"

enctype="multipart/form-data">

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<td><select style="width:572px" name="aksi"> <option value="enc">Enkrypt</option> <option value="dec">Dekrypt</option> </select></br></td>

</form> </table> </p> </div>

style="border-collapse:collapse;"> <tr>

<td width="60"><span

style="width:70px">Plaintext:</span></td>

<td width="50"><textarea type="text" name="pt"

style="width:500px"><? echo stripslashes($pt);

?></textarea></td> </tr> <tr>

<td><input type="text" name="pw"

style="width:500px" value="<?= $pw ?>">

</div> </tr>

</table>

</td><tr><br>

<td width="69">Mode

<option value="">Block CHiper</option> </select>

</td></table>

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<td><button type="submit" name="encr"

style="width:70px" value="Encrypt

it">Encrypt</button></td>

<td><input type="text" name="cipher"

style="width:500px" value="<?= $encr ?>"></td></br> </tr>

<tr><td><button type="submit" name="decr"

style="width:70px" value="Decrypt

it">Decrypt</button></td>

<td><textarea name="plain"

style="width:500px" "\t"><? echo stripslashes($decr);

?></textarea> </table> </form>

</p>

</div></div>

<b><h3>Key Generator</h3></b>

</tr> <tr>

<td>g</td><td> :

</tr>

<tr>

<td>y</td><td> :

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<td>p</td><td> :

</tr> </table> <table>

<b>Bilangan Acak Pengirim (k)</b>

<tr>

<td>k</td><td> :

</tr> </table> <tr>

<td><input type='button'

style="width:227px" value='Bangkitkan Kunci'

onclick="javascript:location.href='key.php';"></td> </tr>

<div class="lg-container3"> <b><h3>Elgamal Key Encryption</b></h3>

<form method="post"> Key :

<table>

<tr>

</tr>

type="submit" name="enkey" value="Encrypt

<td><input type="text"

name="cipherkey" size="20" value="<?=

rtrim($chippertextkey) ?>" "/t"></td> </tr> </table>

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<table>

<tr>

Encrypted Key:

</tr>

<td><button type="submit" name="dekey" value="Decrypt it">Decrypt</button></td>

</tr>

</table> </form>

</div></div></aside>

</body> </html>

Login.php

<table>

<h3 align="center" class="animated

fadeInDown">IMPLEMENTASI DAN ANALISIS KRIPTOGRAFI HYBRID <BR>ALGORITMA FEAL DAN ALGORITMA ELGAMAL <br> DALAM PENGAMANAN FILE TEKS </h3>

<h3 align="center"

class="animated fadeInDown"> <br> SKRIPSI</h3>

<h3 align="center"

class="animated fadeInDown"> <br> Syabrul Majid <br> 131421058</br> <br> <img position="center" src="img/Logo Fasilkom-TI.png" class="single_image"> </br> </h3>

<h3 align="center" class="animated

fadeInDown">FAKULTAS ILMU KOMPUTER DAN TEKNOLOGI

INFORMASI <br> PROGRAM STUDI SARJANA ILMU KOMPUTER</br> UNIVERSITAS SUMATERA UTARA </br> MEDAN</br>2015</br></h3>

</div>

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</table> </div> </html> </body>

ProsesLogin.php

<?php session_start();

require_once("koneksi.php"); $username = $_POST['username']; $pass = $_POST['password'];

$cekuser = mysql_query("SELECT * FROM user WHERE username = '$username'");

$cekpass = mysql_query("SELECT * FROM user WHERE username = '$pass'");

$jumlah = mysql_num_rows($cekuser); $hasil = mysql_fetch_array($cekpass); if($jumlah == 0)

{

echo 'Username Belum Terdaftar!'; echo '<a href="login.php">Back</a>'; }

else {

if($pass = $hasil['password']) {

echo 'Password Salah!';

echo '<a href="login.php">Back</a>'; }

else

{

$_SESSION['username'] = $hasil['username']; header('location:index.php');

} }

?>

Logout.php

<?php session_start();

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echo "<script language=\"javascript\">location.href='login.php';</scrip t>";

?>

Nor1.class.php

<?php

Class FEAL {

public static function cipher($input, $w) {

$Nb = 4;

$Nr = count($w) / $Nb - 1;

$state = array();

for ($i = 0; $i < 4 * $Nb; $i++) $state[$i % 4][floor($i / 4)] = $input[$i];

$state = self::addRoundKey($state, $w, 0, $Nb);

for ($round = 1; $round < $Nr; $round++) { $state = self::subBytes($state, $Nb); $state = self::shiftRows($state, $Nb); $state = self::mixColumns($state, $Nb);

$state = self::addRoundKey($state, $w,

$round, $Nb); }

$state = self::subBytes($state, $Nb); $state = self::shiftRows($state, $Nb);

$state = self::addRoundKey($state, $w, $Nr, $Nb);

$output = array(4 * $Nb);

for ($i = 0; $i < 4 * $Nb; $i++) $output[$i] = $state[$i % 4][floor($i / 4)];

return $output; }

private static function addRoundKey($state, $w, $rnd, $Nb)

{

for ($r = 0; $r < 4; $r++) {

for ($c = 0; $c < $Nb; $c++) $state[$r][$c] ^= $w[$rnd * 4 + $c][$r];

}

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private static function subBytes($s, $Nb) {

private static function shiftRows($s, $Nb) {

private static function mixColumns($s, $Nb) {

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$Nb = 4; self::$rCon[$i / $Nk][$t];

} else if ($Nk > 6 && $i % $Nk == 4) {

private static function subWord($w) {

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0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,

0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,

0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,

0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,

0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,

0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,

0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,

0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,

0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,

0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,

0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,

0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,

0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,

0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,

0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,

0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16);

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Norctr.class.php

<?php

Class FEALCtr extends FEAL {

public static function encrypt($plaintext, $password, $nBits)

{

$blockSize = 16;

if (!($nBits == 128 || $nBits == 192 || $nBits == 256)) return '';

$nBytes = $nBits / 8; $pwBytes = array();

for ($i = 0; $i < $nBytes; $i++) $pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;

$key = FEAL::cipher($pwBytes,

FEAL::keyExpansion($pwBytes));

$key = array_merge($key, array_slice($key, 0, $nBytes - 16));

$counterBlock = array();

$nonce = floor(microtime(true) * 1000); $nonceMs = $nonce % 1000;

$nonceSec = floor($nonce / 1000); $nonceRnd = floor(rand(0, 0xffff));

for ($i = 0; $i < 2; $i++) $counterBlock[$i] = self::urs($nonceMs, $i * 8) & 0xff;

for ($i = 0; $i < 2; $i++) $counterBlock[$i + 2] = self::urs($nonceRnd, $i * 8) & 0xff;

for ($i = 0; $i < 4; $i++) $counterBlock[$i + 4] = self::urs($nonceSec, $i * 8) & 0xff;

$ctrTxt = '';

for ($i = 0; $i < 8; $i++) $ctrTxt .= chr($counterBlock[$i]);

$keySchedule = FEAL::keyExpansion($key);

$blockCount = ceil(strlen($plaintext) /

$blockSize);

$ciphertxt = array();

for ($b = 0; $b < $blockCount; $b++) {

for ($c = 0; $c < 4; $c++) $counterBlock[15 - $c] = self::urs($b, $c * 8) & 0xff;

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$cipherCntr = FEAL::cipher($counterBlock, $keySchedule);

$blockLength = $b < $blockCount - 1 ? $blockSize : (strlen($plaintext) - 1) % $blockSize + 1; $cipherByte = array();

for ($i = 0; $i < $blockLength; $i++) {

$cipherByte[$i] = $cipherCntr[$i] ^

ord(substr($plaintext, $b * $blockSize + $i, 1));

$cipherByte[$i] = chr($cipherByte[$i]); }

$ciphertxt[$b] = implode('', $cipherByte); }

$ciphertext = $ctrTxt . implode('', $ciphertxt); $ciphertext = base64_encode($ciphertext);

return $ciphertext; }

public static function decrypt($ciphertext,

$password, $nBits) {

$blockSize = 16;

if (!($nBits == 128 || $nBits == 192 || $nBits == 256)) return '';

$ciphertext = base64_decode($ciphertext);

$nBytes = $nBits / 8; $pwBytes = array();

for ($i = 0; $i < $nBytes; $i++) $pwBytes[$i] = ord(substr($password, $i, 1)) & 0xff;

$key = FEAL::cipher($pwBytes,

FEAL::keyExpansion($pwBytes));

$key = array_merge($key, array_slice($key, 0, $nBytes - 16));

$counterBlock = array();

$ctrTxt = substr($ciphertext, 0, 8);

for ($i = 0; $i < 8; $i++) $counterBlock[$i] = ord(substr($ctrTxt, $i, 1));

$keySchedule = FEAL::keyExpansion($key);

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$nBlocks = ceil((strlen($ciphertext) - 8) / $blockSize);

$ct = array();

for ($b = 0; $b < $nBlocks; $b++) $ct[$b] = substr($ciphertext, 8 + $b * $blockSize, 16);

$ciphertext = $ct; $plaintxt = array();

for ($b = 0; $b < $nBlocks; $b++) {

for ($c = 0; $c < 4; $c++) $counterBlock[15 - $c] = self::urs($b, $c * 8) & 0xff;

for ($c = 0; $c < 4; $c++) $counterBlock[15 - $c - 4] = self::urs(($b + 1) / 0x100000000 - 1, $c * 8) & 0xff;

$cipherCntr = FEAL::cipher($counterBlock,

$keySchedule);

$plaintxtByte = array();

for ($i = 0; $i < strlen($ciphertext[$b]); $i++) {

$plaintxtByte[$i] = $cipherCntr[$i] ^

ord(substr($ciphertext[$b], $i, 1));

$plaintxtByte[$i] =

chr($plaintxtByte[$i]);

}

$plaintxt[$b] = implode('', $plaintxtByte); }

$plaintext = implode('', $plaintxt);

return $plaintext; }

private static function urs($a, $b) {

$a &= 0xffffffff; $b &= 0x1f;

if ($a & 0x80000000 && $b > 0) { $a = ($a >> 1) & 0x7fffffff; $a = $a >> ($b - 1);

} else {

$a = ($a >> $b); }

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}

/* - - - - - - */

Key.php

<?php

session_start();

$key = new elgamal(0,0,0,0,0); $key->_key(258);

$_SESSION[p] = $key->p; $_SESSION[g] = $key->g; $_SESSION[x] = $key->x; $_SESSION[y] = $key->y; $_SESSION[k] = $key->k;

echo "<script

language=\"javascript\">location.href='index.php';</scrip t>";

?>

<html><h1>Please Wait</h1> </html>

feal.php

<?php

session_start();

$pw = empty($_POST['pw']) ? '' : $_POST['pw'];

$pt = empty($_POST['pt']) ? '' : $_POST['pt'];

$_POST['cipher'];

$_POST['plain'];

$encr = empty($_POST['encr']) ? $cipher :

FEALCtr::encrypt($pt, $pw, 256) ;

$decr = empty($_POST['decr']) ? $plain :

FEALCtr::decrypt($cipher, $pw, 256);

$enkripsi = new

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$dekripsi = new elgamal($_SESSION['p'],$_SESSION['g'],$_SESSION['x'],$_SE SSION['y'],$_SESSION['k']);

$cipherkey = empty($_POST['cipherkey']) ? '' : $_POST['cipherkey'];

$plainkey = empty($_POST['plainkey']) ? '' : $_POST['plainkey'];

$chippertextkey = empty($_POST['enkey']) ?

$cipherkey : $enkripsi->_enkripsi($pw) ;

$plaintextkey = empty($_POST['dekey']) ? $plainkey : $enkripsi->_dekripsi($cipherkey) ;

?>

<!DOCTYPE html>

<head>

content="IE=edge">

content="width=device-width, initial-scale=1">

<title>IMPLEMENTASI DAN ANALISIS KRIPTOGRAFI HYBRID <br> ALGORITMA FEAL DAN ALGORITMA ELGAMAL <br> DALAM PENGAMANAN FILE TEKS</title>

rel="stylesheet" />

</head> <header>

<div class="col-md-6 col-sm-6 col-xs-6 text-right

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<a id="trigger-overlay" class="nav_slide_button nav-toggle"

href="../template/index.php"><span></span></a></div> </div>

function showHide(aMenu) {

var aMenu = document.getElementById(aMenu);

aMenu.style.display = (aMenu.style.display == "block") ? "none" : "block";

}

</script>

{

"muncul"){document.getElementById('DivTampil').style.disp lay="inline"}

"muncul"){document.getElementById('DivTampil2').style.dis play="none"}

"hilang"){document.getElementById('DivTampil').style.disp lay="none"}

"hilang"){document.getElementById('DivTampil2').style.dis

<td>Choose   : </td>

<select style="width:500px" name='NamaSelection'

onchange='DisplayShowHide()'>

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</table>

<form action="file-processor.php" method="post"

enctype="multipart/form-data">

<br><input type="file" name="fName"> <br>Pilih Proses :

<select style="width:770px" name="aksi"> <option value="enc">Enkripsi</option> <option value="dec">Dekripsi</option> </select></br>

</form> </table> </p> </div>

style="border-collapse:collapse;"> <tr>

<td width="60"><span

style="width:70px">Plaintext:</span></td>

<td width="50"><textarea type="text" name="pt"

style="width:500px"><? echo stripslashes($pt);

?></textarea></td> </tr> <tr>

<td><input type="text" name="pw"

style="width:500px" value="<?= $pw ?>">

<div class="wrapper"> <div class="menuHeader"

onclick="showHide('menu1')">Encrypt Key </div>

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<tr>

<td colspan='2'><b>Kunci

Publik</b></td>

</tr> <tr>

<td

width='150'>p</td><td>: <input type="text" rows="10" cols="60" value="<?= $_SESSION['p'] ?>"></td>

</tr> <tr>

</tr> <tr> <tr>

</tr>

<td colspan='2'><b>Kunci

Privat</b></td>

</tr> <tr>

</tr> <tr>

</tr> </tr>

<td colspan='2'><b>Bilangan Acak Pengirim (k)</b></td>

</tr> <tr>

</tr> <tr>

<td colspan='2'><input

type='button' value='Bangkitkan Kunci'

onclick="javascript:location.href='key.php';"></td> </tr>

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<td width='150' valign='top'>PlainText</td>

<td>

<form

enctype="multipart/form-data" method='POST'

action='enkripsi.php'>

<td width='150'

valign='top'>ChipperText</td>

<td>

<form

enctype="multipart/form-data" method='POST'

action='dekripsi.php'>

</tr>

</table>

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<td><button

type="submit" name="enkey" value="Encrypt

<td><button type="submit" name="dekey" value="Decrypt it">Decrypt</button></td>

</td><tr><br>

<td width="69">Mode

<option value="">Block CHiper</option> </select>

</td></table>

<td><button type="submit" name="encr"

style="width:70px" value="Encrypt

<td><input type="text" name="cipher"

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<tr><td><button type="submit" name="decr"

style="width:70px" value="Decrypt

it">Decrypt</button></td>

<td><textarea name="plain"

style="width:500px" "\t"><? echo stripslashes($decr);

?></textarea> </table> </form>

</p>

</div><a class="chosen-single" tabindex="-1"> <tr id="row-frm-text">

</body> </html>

Elgamal.php

<?php

class elgamal{

public static $p,$g,$x,$y,$k;

public function __construct($p,$g,$x,$y,$k){ $this->p = $p;$this->g = $g;

$this->x = $x;$this->y = $y; $this->k = $k;

}

public function _key($batas){

$this->p = $this->_p($batas); $this->g = $this->_g();

$this->x = $this->_x();

$this->y = $this->_y($batas); $this->k = $this->_k();

}

private function _p($batas){

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return $this->_p($batas); }

}

private function _g(){

return rand(1,$this->p - 1); }

private function _x(){

private function _y($batas){

return

$this->_rekursifMod($this->g,$this->x,$this->p);

}

private function _k(){

public function _rekursifMod($basis,$pangkat,$mod){ if ($pangkat <= 2)

return ((pow($basis,$pangkat)) % $mod); else{

$s = $pangkat % 2; if ($s == 0){

$b = $pangkat / 2; $b1 = $b; $b2 = $b; }

else{

$b = floor($pangkat/2); $b1 = $b; $b2 = $b + 1; }

return

((($this->_rekursifMod($basis,$b1,$mod)) *

($this->_rekursifMod($basis,$b2,$mod))) % $mod); }

}

(28)

$chipperText = "";

for ($i=0;$i<(strlen($ascii));$i+=3){ $tmp = substr($ascii,$i,3);

if (strlen($tmp)==1) $tmp = "00".$tmp; if (strlen($tmp)==2) $tmp = "0".$tmp;

$r = $this->_rekursifMod($this->g,$this->k,$this->p);

$s =

((($this->_rekursifMod($this- >y,$this->k,$this->p))*($this->_rekursifMod($tmp,1,$this->p))) % $this->p);

$chipperText .= $r." ".$s." ";

}

return $chipperText; }

public function _dekripsi($chipperText){ $t = explode(" ",$chipperText); $ascii = ""; if (strlen($b)==1) $b = "00".$b; if (strlen($b)==2) $b = "0".$b; $ascii .= $b;

}

return $this->_toText($ascii); }

private function _toAscii($text){ $ascii = "";

for ($i=0;$i<(strlen($text));$i++){ $char = substr($text,$i,1); $a = ord($char);

if (strlen($a)==1) $a = "00".$a; if (strlen($a)==2) $a = "0".$a;

private function _toText($ascii){ $text = "";

(29)

$text .= chr($bil); }

return $text; }

} ?>

File-processor.php

<?php

$pt = empty($_POST['pt']) ? '' : $_POST['pt'];

$_POST['cipher'];

$_POST['plain'];

$target_dir = "upload/"; $aksi=$_POST['aksi']; $pw=$_POST['pw'];

$targetFile = basename( $_FILES["fName"]["name"]); //option aksi

if($aksi=='enc'){

if (move_uploaded_file($_FILES["fName"]["tmp_name"],

$target_dir.$targetFile)) { $success=true;

/*---*/

$fh = fopen($target_dir.$targetFile,

'r');//membuka file hasil upload

$pt = fread($fh, 2097152); fclose($fh);

$encr = rtrim($_POST["fName"]) ?

$cipher : FEALCtr::encrypt($pt, $pw, 256) ;

$fp = fopen($target_dir.$targetFile,

'wb');//menimpa file hasil upload dengan file hasil enkripsi

fwrite($fp,$encr); fclose($fp);

(30)

$success=false; }

}

else if($aksi='dec'){

if(move_uploaded_file($_FILES["fName"]["tmp_name"], $target_dir.'/'.$targetFile)){

/*---*/

$fh = fopen($target_dir.'/'.$targetFile, 'r');

$cipher = fread($fh, 2097152); fclose($fh);

$decr = rtrim($_POST['decr']) ? $plain : FEALCtr::decrypt($cipher, $pw, 256);

$fp = fopen($target_dir.$targetFile,

'wb');

fwrite($fp,$decr); fclose($fp);

} }

?> <html>

<h2>Succes Proccess:</h2> <h3><br><i><u><?= $targetFile ?></u></i></h3>

<a download href="<?= $target_dir.$targetFile ?>"

style="text-decoration:none">

<center><br><img src="download.png"

width="50px" height="50px" alt="Home" > </br>