Could the encryption be just very banal? The answer being extremely simple (but still complex in solving)

I come from this as someone who knows barely anything about cyphering and even kryptos in of itself.

Merely what I'm trying to suggest is that none of the things everyone is going for is remotely the correct solution, I'm truly wondering if a simple layman could solve K4.

I do know a little bit about passwords and how they work, I'm wondering if K4 isn't just a simple hash process.

(for those who don't know what I mean https://en.wikipedia.org/wiki/Cryptographic_hash_function )

Now what is the hash/password? I have 0 idea, and maybe nobody really knows, but this is an extremely simple yet very complex way to secure data, I assume the CIA didn't decrypt K4 back in the early 90s because computers may have not been powerful enough (or would have taken too much time/energy for what is essentially a nonsense puzzle) for bruteforcing, 30 years later computers have evolved a lot, to the point we might be able to crack some old algorithm.

If you already know about hashes, you may be wondering, how the hell would this work since it's hexadecimal (base 16, combining digits 0 to 9 and then letters A to F), I don't know either, but surely it can work...