Re: AES-related question

AES is based on a design principle known as a Substitution permutation
network. It is fast in both software and hardware.[6] Unlike its
predecessor, DES, AES does not use a Feistel network.
AES has a fixed block size of 128 bits and a key size of 128, 192, or
256 bits,

Actually, OP problem can be solved: size_key>size_block doesn't allow
to get bijective function:-)