The Rijndael S-Box

[@osamaxz5720]

thanks from depth of my heart. All people who explain AES copy pre-calculated S-BOX table and explain some operations on GF(2^8) and I really got tired from bad videos trying to explain how to build the S-BOX table and you really was my savior thanks

[@matthishaddouche6574]

Really, it’s great, great work. I found it extremely clear, and we all know that it’s a challenge to simplify such complexe subject. Thank you for this hight quality content.

[@JacksonInfoSec]

Thanks very much for your kind words!

[@faridzaredar6529]

Perfect video I do appreciate for your clean and fresh video.

[@JacksonInfoSec]

Thanks for your kind words, glad you enjoyed the video!

[@supersteve1440]

For number_bits, you could use the bit_length() method of an int.

[@felipedeandrade]

Excellent explanation. Thank you, really.

[@JacksonInfoSec]

My pleasure, thanks for watching.

[@James-qb6cs]

great explanation, thanks!

[@JacksonInfoSec]

Glad it was helpful!

[@hariselahi9979]

Great video sir..i have a question will it work if i input x and y value first ?

[@MaRaBuNTa2RoKR]

Hi. Could you tell me which is the book above "Silverman - The Arithmetic Of Elliptic Curves"? Thanks. Nice explanation.

[@JacksonInfoSec]

Yes it is Silverman, the other one is Knapp.

[@digitalconsciousness]

From reading on wikipedia about the S-Box, it states that a Perfect S-Box is one that utilizes Bent Functions. Wikipedia states that Bent Functions are "as far away from linear and affine functions as possible". Since the Rijndael S-Box uses an affine transformation, does that mean it is not a perfect s-box? Would it be more secure if it was? Thank you for making this video by the way.

[@JacksonInfoSec]

Although the Rijndael S-Box does use an affine transformation, remember that the Rijndael inversion is first applied to the input. Therefore the final composition will not be affine. I will look more into the notions of perfect S-Box and bent functions.

[@digitalconsciousness]

@@JacksonInfoSec Thanks for the reply!

[@akramkermiche2772]

I have a question please ... if I want to produce my own S_box which parameters should I change whit keeping the same level of security

[@wanglei40]

Thanks a lot!

[@JacksonInfoSec]

You're welcome!