tripledes

http://blog.kotowicz.net/2010/09/story-of-android-cryptography-and.html

import java.io.UnsupportedEncodingException;
import java.security.GeneralSecurityException;
import javax.crypto.Cipher;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
* @author rdamazio
* @see http://code.google.com/p/android-notifier/
*/
public class Encryption {

public static int MAX_KEY_LENGTH = DESedeKeySpec.DES_EDE_KEY_LEN;
private static String ENCRYPTION_KEY_TYPE = "DESede";
private static String ENCRYPTION_ALGORITHM = "DESede/CBC/PKCS5Padding";
private final SecretKeySpec keySpec;

public Encryption(String passphrase) {
    byte[] key;
    try {
     // get bytes representation of the password
     key = passphrase.getBytes("UTF8");
    } catch (UnsupportedEncodingException e) {
     throw new IllegalArgumentException(e);
    }

    key = padKeyToLength(key, MAX_KEY_LENGTH);
    keySpec = new SecretKeySpec(key, ENCRYPTION_KEY_TYPE);
}

// !!! - see post below
private byte[] padKeyToLength(byte[] key, int len) {
    byte[] newKey = new byte[len];
    System.arraycopy(key, 0, newKey, 0, Math.min(key.length, len));
    return newKey;
}

// standard stuff
public byte[] encrypt(byte[] unencrypted) throws GeneralSecurityException {
    return doCipher(unencrypted, Cipher.ENCRYPT_MODE);
}

public byte[] decrypt(byte[] encrypted) throws GeneralSecurityException {
    return doCipher(encrypted, Cipher.DECRYPT_MODE);
}

private byte[] doCipher(byte[] original, int mode) throws GeneralSecurityException {
    Cipher cipher = Cipher.getInstance(ENCRYPTION_ALGORITHM);
    // IV = 0 is yet another issue, we'll ignore it here
    IvParameterSpec iv = new IvParameterSpec(new byte[] { 0, 0, 0, 0, 0, 0, 0, 0 });
    cipher.init(mode, keySpec, iv);
    return cipher.doFinal(original);
}
}