Why is AES secure? Apparently there is no answer - Why is AES resistant to known-plaintext attacks?.
With this in mind, one would obviously want a cipher that is mathematically provable to be resistant to KPA. How would one go about constructing such a cipher? Has it been done? Can it be done? Is someone doing it? Why hasn't it been done? Can you blame mathematics atleast?
When I look at AES, I see a bunch of random up-the-sleeves operations, with, as aforementioned, mostly no explanation. Why can't there be a simple, efficient and secure algorithm to encrypt things?
Imagine a simple (e.g. xor) cipher with a 256-bit key that is applied to each 256 bit aligned block of the plaintext. Suppose it wasn't vulnerable to KPA and other attacks. Then it would be equally secure as AES-256, if not better, given the potential flaws of AES. Problem solved? Unfortunately not; contradiction.