(Android™) ARC4 Encryption (ARCFOUR)

ARC4 (ARCFOUR) encryption. The Chilkat encryption component supports the ARC4 streaming encryption algorithm.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkCrypt2 crypt = new CkCrypt2();

    // Set the encryption algorithm = "arc4"	
    crypt.put_CryptAlgorithm("arc4");

    // KeyLength may range from 1 byte to 256 bytes.
    // (i.e. 8 bits to 2048 bits)
    // ARC4 key sizes are typically in the range of 
    // 40 to 128 bits.
    // The KeyLength property is specified in bits:
    crypt.put_KeyLength(128);

    // Note: The PaddingScheme and CipherMode properties
    // do not apply w/ ARC4.  ARC4 does not encrypt in blocks --
    // it is a streaming encryption algorithm. The number of output bytes
    // is exactly equal to the number of input bytes.

    // EncodingMode specifies the encoding of the output for
    // encryption, and the input for decryption.
    // It may be "hex", "url", "base64", or "quoted-printable".
    crypt.put_EncodingMode("hex");

    // Note: ARC4 does not utilize initialization vectors.  IV's only
    // apply to block encryption algorithms.  

    // The secret key must equal the size of the key.
    // For 128-bit encryption, the binary secret key is 16 bytes.
    String keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F";
    crypt.SetEncodedKey(keyHex,"hex");

    // Encrypt a string...
    // The output length is exactly equal to the input.  In this
    // example, the input string is 44 chars (ANSI bytes) so the
    // output is 44 bytes -- and when hex encoded results in an
    // 88-char string (2 chars per byte for the hex encoding).
    String encStr = crypt.encryptStringENC("The quick brown fox jumps over the lazy dog.");
    Log.i(TAG, encStr);

    // Now decrypt:
    String decStr = crypt.decryptStringENC(encStr);
    Log.i(TAG, decStr);

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}