Nope, even smoke signals have bugs in them.
Nothing is secure, you just have to try your best and arm yourself with as much salt as possible. All you can do is try, you can keep 99% of people out with various methods, but eventually you will be exploited.
...thats only if you are targeted by an individual or a group for a particular reason. If someone wants your information and they are intelligent, then all it takes is time.
If its legal in your country, you should try out AES-256 encryption.



