(Chilkat for Android™ API)
ARC4 PRNG (Pseudo Random Number Generator)

Uses the ARC4 stream encryption algorithm as a pseudo random number generator.

Download: Chilkat for Android™ Java 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 {
  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    TextView tv = new TextView(this);
    String outStr = "";

    CkCrypt2 crypt = new CkCrypt2();

    boolean success;
    success = crypt.UnlockComponent("Anything for 30-day trial");
    if (success != true) {
        outStr += "Crypt component unlock failed" + "\n";
        tv.setText(outStr);
        setContentView(tv);
        return;
    }

    //  Set the encryption algorithm to ARC4:
    crypt.put_CryptAlgorithm("arc4");

    //  We want the encrypted output to be a hex-encoded string.
    crypt.put_EncodingMode("hex");

    String key;
    key = "000102030405060708090A0B0C0D0E0F";

    String data;
    data = "12345678";

    //  Key length is 128 bits in this example.
    crypt.put_KeyLength(128);
    crypt.SetEncodedKey(key,"hex");

    //  Generate 16 "random" 8-byte blocks, encoded as hex strings.
    //  This example will generate the identical output each time
    //  it is run.
    String cipherHex;
    int i;
    for (i = 0; i <= 15; i++) {
        cipherHex = crypt.encryptStringENC(data);
        outStr += data + "\n";
        outStr += cipherHex + "\n";
        data = cipherHex;
    }

    tv.setText(outStr);
    setContentView(tv);
  }

  static {
      // Important: Make sure the name passed to loadLibrary matches the shared library
      // found in your project's libs/armeabi directory.
      //  for "libchilkat.so", pass "chilkat" to loadLibrary
      //  for "libchilkatemail.so", pass "chilkatemail" to loadLibrary
      //  etc.
      // 
      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."
  }
}