Attacking AES without transposition using ShiftRow and Mixcolumn layers How can we attack by using chosen plaintext attack (and which plaintext should we choose) if AES didnt have the ShiftRow and Mixcolumn layers. I know each byte would be independent in the 16 byte scheme but couldnt figure out a way to attack.
After the key expansion, there would be 16 different mappings for each of the 16 bytes in a block. 

Suppose we are attacking the block cipher itself (in ECB mode), with each byte having 256 different values, we can query 256 ciphertext blocks (all-bytes-0, all-bytes-1, ... all-bytes-255) to get the exact plaintext-to-ciphertext mapping for all 16 bytes's 256 values. 

To decrypt future blocks, you just need to have a 16x256=4096 byte (1 memory page) table of the inverse map which you can easily create now.