code: public IvParameterSpec init(SecretKey key) throws InvalidKeyException{
  		byte[] iv = new byte[key.getEncoded().length];
  		new SecureRandom().nextBytes(iv);
  		IvParameterSpec ivSpec =  new IvParameterSpec(iv);
  		init(key, ivSpec);
  		return ivSpec;
  	}
docs: Initializes the cipher with key, creates a random IV to use with the cipher.
  @param key A key to encrypt with. Key can be any length over MIN_KEY_SIZE but a key longer than the block size will run more slowly.
  @return An IV that has been created for this cipher to use. IV will be the same length as the key.
  @throws InvalidKeyException