RC4 Encryption

Berikut ini adalah source code sederhana untuk enkripsi RC4. Source code ini dibuat menggunakan bahasa pemrograman Java.


import java.io.*;

//import java.lang.Character;

/**

*

* @author zlich

*/

public class RC4 {

public static void main (String [] args) throws IOException {

int [] key = null;

int keylen = 0;

int k = 0;

int [] SBox = new int [256]; DataInputStream input = new DataInputStream(System.in);
//inisialisasi S-Box

for (int i = 0; i 0) {

key = new int [keylen];

}

for (k=0; k<keylen; k++) {

key[k] = kunci.charAt(k);
System.out.print(key[k] + " ");

}
//permutasi S-Box

int i, j = 0;

for (i=0; i<256; i++) {

j = (j + SBox[i] + key[i % key.length]) % 256;
//swap

int temp = SBox[i];

SBox[i] = SBox[j];

SBox[j] = temp;

}
//Input Plaintext

System.out.println("\nPlaintext: ");

String plaintext = input.readLine();
//PRGA

int a = 0;

int b = 0;

for (i=0; i<plaintext.length(); i++) {

a = (a + 1) % 256;

b = (b + SBox[a]) % 256;
//swap

int temp = SBox[a];

SBox[a] = SBox[b];

SBox[b] = temp;
//pseudorandom generation

int pseudo = SBox[(SBox[a] + SBox[b]) % 256];

int chartext = plaintext.charAt(i);
//XOR

int chiper = pseudo ^ chartext;

System.out.print(Integer.toHexString(chiper).toUpperCase()); //chipertext

//System.out.print(Character.toChars(chiper));

}

}

}




Source codenya masih menggunakan prosedural, untuk pendekatan OOP sedang diusahakan.
Kalau dicompile terus dieksekusi outputnya kayak gini:

Key:
pwd12
112 119 100 49 50
Plaintext:
Math 310 Proves!
6CA86FE3CBC33C162595C3E78B9C97BC

Selamat Mencoba!!