code: private byte[] encryptInternal(SecretKeySpec key, String toEncrypt) {
          try {
              Cipher cipher = Cipher.getInstance(ENCRYPTION_ALGORITHM + ENCRYPTION_ALGORITHM_MODIFIER);
              cipher.init(Cipher.ENCRYPT_MODE, key);
              return cipher.doFinal(toEncrypt.getBytes(ENCODING));
          } catch (GeneralSecurityException e) {
              throw new RuntimeException("Exception during decryptInternal: " + e, e);
          } catch (UnsupportedEncodingException e) {
              throw new RuntimeException("Exception during encryptInternal: " + e, e);
          }
      }
docs: Internal Encryption method.
  
  @param key       - the SecretKeySpec used to encrypt
  @param toEncrypt - the String to encrypt
  @return the encrypted String (as byte[])