Uploaded January 2016 | Updated September 2026, 2 weeks ago
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.
This has been a tricky one to upload, I had it as one vid, but it was too long. So I split the matrix multiplication part to a separate vid. Hopefully, it's better that way.
Wikipedia page with mul2 and mul3 look-up tables:
en.wikipedia.org/wiki/Rijndael_mix_columns
Become a patron and support What's a Creel programming vids on Patreon:
patreon.com/whatsacreel
FaceBook:
facebook.com/pages/WhatsaCreel/167732956665435
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.
This has been a tricky one to upload, I had it as one vid, but it was too long. So I split the matrix multiplication part to a separate vid. Hopefully, it's better that way.
Wikipedia page with mul2 and mul3 look-up tables:
en.wikipedia.org/wiki/Rijndael_mix_columns
Become a patron and support What's a Creel programming vids on Patreon:
patreon.com/whatsacreel
FaceBook:
facebook.com/pages/WhatsaCreel/167732956665435
