Java Tutorial/Security/ARC

Basic stream cipher example

import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
public class MainClass {
  public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] input = "input".getBytes();
    byte[] keyBytes = "input123".getBytes();
    SecretKeySpec key = new SecretKeySpec(keyBytes, "ARC4");
    Cipher cipher = Cipher.getInstance("ARC4", "BC");
    byte[] cipherText = new byte[input.length];
    cipher.init(Cipher.ENCRYPT_MODE, key);
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    System.out.println("cipher text: " + new String(cipherText));
    byte[] plainText = new byte[ctLength];
    cipher.init(Cipher.DECRYPT_MODE, key);
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println("plain text : " + new String(plainText));
  }
}