AES Encryption 3: MixColumns 1 Dot Products (Patreon)

This video is on the MixColumns step in the inner loop of AES. Most of the topic for today is on how to manually multiply Galois fields, reduce them mod some polynomial, and add them together to compute a dot product. This is an important step in the construction of several look-up tables which form the basis of the mix columns step. We will eventually do the multiplication and reductions via a handful of lookup tables. This video does not present the entire MixColumns step but the rest is a little simpler once we look at dot products.