Encryption and decryption in android using AESHelper

In this article we will learn how make a program which to helps you learn how you can perform encryption/decryption with java.

In this post I explain the encryption and decryption of string using Cipher class.

Below is the class in which method for encryption and decryption.

Add this class in your android project package.

import javax.crypto.Cipher;

import javax.crypto.spec.SecretKeySpec;

import android.util.Base64;

public class AESHelper{

        public static String encrypt(String seed, String cleartext) throws Exception {

                byte[] rawKey = seed.getBytes();

                byte[] result = encrypt(rawKey, cleartext.getBytes());

                return Base64.encodeToString(result, Base64.DEFAULT);

        }

        public static String decrypt(String seed, String encrypted) throws Exception {

                byte[] rawKey = seed.getBytes();

                byte[] enc = Base64.decode(encrypted, Base64.DEFAULT);

                byte[] result = decrypt(rawKey, enc);

                return new String(result);

        }

      

        private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {

            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");

                Cipher cipher = Cipher.getInstance("AES");

            cipher.init(Cipher.ENCRYPT_MODE, skeySpec);

            byte[] encrypted = cipher.doFinal(clear);

                return encrypted;

        }

        private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {

            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");

                Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");

            cipher.init(Cipher.DECRYPT_MODE, skeySpec);

            byte[] decrypted = cipher.doFinal(encrypted);

                return decrypted;

        }

}

For encryption of the string using this class

AESHelper.encrypt(HERE IS YOUR ENCRYPTION KEY, HERE PASS YOUR STRING TO BE ENCRYPT);

For decryption of the string using above class

AESHelper.decrypt(HERE IS YOUR ENCRYPTION KEY, HERE PASS YOUR STRING TO BE DECRYPT);

NOTE : Make sure that your key is of 128 bit or higher.

Hope this post is helpful for you...