code: public byte[] decryptData(byte[] data) throws SymmetricKeyException {
          if (data.length < IV_SIZE)
              throw new SymmetricKeyException("Invalid encrypted data, no IV prepended");
          byte[] iv = ArrayUtils.subarray(data, 0, IV_SIZE);
          Cipher cipher = getCipher(Cipher.DECRYPT_MODE, iv);
          try {
              return cipher.doFinal(data, iv.length, data.length - iv.length);
          } catch (Exception e) {
              throw new SymmetricKeyException(e);
          }
      }
docs: Decrypt the encrypted byte array data. The encrypted data must be prefixed with the
  IV header (16 bytes) used when encrypting the data.
  @param data Encrypted data
  @return Decrypted data
  @throws SymmetricKeyException