Can Any Computer Program Be Secured Against Advanced Intelligence?

I suspect the answer is no, and that the best you could hope for is to detect intrusion, and I suspect that will only hold if P!=NP, and I'm not even sure I fully believe that detection of changes can hold. My gut feeling is that nothing is secure. I suspect that every system is vulnerable in ways that we scantly understand. Though, for the time being, we could probably still use hash functions to detect changes in the system, but even expecting that to hold is wishful thinking, if for no other reason than the fact that you have to store those hashes somewhere. I've gotten the feeling over the past two days that everything is vulnerable.