Let me avoid the technical aspects to make things easy for all readers.
So someone said that America's NSA has this great computer(quantum computer) that could easily hack Bitcoin private keys. I really doubt his claim but I know for sure that certain computers like the most powerful Super Computers are within the reach of some of this Intelligence organizations.
Do you think such computers can crack any security codes put in place to make Bitcoin very secure?
Everything is possible to happen. Using super Computers maybe can hack bitcoin but if the computer upgrade the bitcoin security also upgrade and as the years has past the bitcoin continue to develop including it's security from a lot of hackers and thief.