Spend some time on Cardano's website: https://cardano.org
Spend as much time as you possibilty can, with the goal of finding a problem, any problem, anything that even makes you just a little uneasy. I'm serious. (Let me know about anything that you come up with that I may have missed.)
There's a lot there, I'll admit. Here's a good place to start in order to see if you want to continue investing your time there. https://cardano.org/ouroboros
Just a tidbit:
Ouroboros is the first provably secure proof-of-stake protocol, and the first blockchain protocol to be based on peer-reviewed research.
RE: Zero HIVE