alt Hacker NewsIt didn't take 25 years to come up with Symmetric Encryption and AES but even though people try extensively to break it for the last 25 years no-one has come even close to anything that is not brute force (which is practically impossible even assuming very generous computing resources). So at least in that case coming up with the encryption seems to be a very solvable problem but breaking it seems close to impossible.
It’s worth considering AES is the result of many decades of development of prior block cipher algorithms. It is no so hard to make a variant of AES that looks similar but is not secure.