public static void main(String[] args) throws IOException{
		String test = "This is a pen.";
		byte[] value = new byte[20];
		for(int i = 0; i < test.length(); i++){
			value[i] = (byte) test.charAt(i);
		}
		EncryptOutputStream e = new EncryptOutputStream(new FileOutputStream("test2003"));
		for(int i = 0; i < value.length; i++){
			e.write(value[i]);
		}
		DecryptInputStream d = new DecryptInputStream(new FileInputStream("test2003"));
		int c = 0;
		for(; ;){
			if((c = d.read()) != -1){
				System.out.println("after decryption : " + c);
				e.close();
				d.close();
			}
		}

	}