I'm reading FIPS 197 (AES) to try and understand how the algorithm works but I don't yet have answer for are these two questions:
- I see the 256 byte s-box for substituting during the rounds. Do the values in this 256 byte table get updated or is it a static table for the whole transformation?
- In key expansion, I see that the key is expanded based on the amount of rounds there are which determined by the size of the key (128, 192, or 256). But does the expanded key ever change or is it static for the whole transformation?