[richardthered]

Unbreakable cryptography is real.

https://en.wikipedia.org/wiki/One-time_pad

"If the key is truly random, is at least as long as the plaintext, is never reused in whole or in part, and is kept completely secret, then the resulting ciphertext will be impossible to decrypt or break"

[jessaustin]

That's not a great example in this case, because any useful system that incorporated OTP would have to store the really long secret keystream somewhere. That somewhere would be vulnerable to subpoena.