Even if the mathematical theories were flawless, hackers will start by looking at the algorithm used (how the math is applied), then proceed with the source code (how it is translated in computer language), then the way it's compiled, then how it interacts with the OS and if it's not enough, look at the hardware (and it's a whole new story). Without speaking about the weakest link: the user (social engineering, cognitive bias, etc.).
There is a reason why critical systems are air gapped. And sometimes it's not even enough.
So, let me stand behind my point here: there is no such thing as computer security.
I really hope no one here, if given the chance, would put the nuclear launch codes on the cloud
Anyway, my $0.02