All modern cryptography is built on the same principle: the encryption scheme is defined by the key. And even if the cryptography itself is "conditionally reliable" or absolutely reliable (Vernam's ciphers), the fact of having a key will always be a natural vulnerability, which will be actively exploited by fraudsters in the first place. It is this vulnerability factor that instantly, irrevocably, completely levels out and weakens to zero any most reliable cryptographic system. Moreover, it has fatal consequences if the fact of compromising key information remains a mystery to the attacker. For this reason, all new post-quantum encryption systems, any key encryption technology, all the latest security systems of tomorrow will be no exception.
Any security system, a security protocol based on cryptography with a mandatory key function, will be attacked first, through the encryption keys, through its weakest point.