Comment by raincom

S-box is used in symmetric ciphers in cryptography. S-box = substitution box or lookup table [3][4]. You can see an example of Rijndael s-box in a python script here [1][2].

[1] https://github.com/kokke/tiny-AES-c/blob/f06ac37fc31dfdaca2e...

[2] https://anh.cs.luc.edu/331/code/aes.py

[3] https://en.wikipedia.org/wiki/S-box

[4] https://en.wikipedia.org/wiki/Rijndael_S-box