In 1997, a contest began to develop a new encryption algorithm to become the Advanced Encryption Standard. After years of debate, one algorithm was chosen as the AES. But how does AES work? And what makes for a secure encryption algorithm?

***

Spanning Tree is an educational video series about computer science and mathematics. See more at https://spanningtree.me

To be notified when a new video is released, sign up for the Spanning Tree mailing list at https://spanningtree.substack.com/

Spanning Tree is created by Brian Yu. https://brianyu.me/

Email me at [email protected] to suggest a future topic.

***

0:00 The Contest
1:02 Encryption
3:57 Confusion and Diffusion
5:44 Block Cipher
6:55 KeyExpansion
7:34 AddRoundKey
8:14 Substitution Cipher
8:55 SubBytes
11:30 MixColumns
12:53 ShiftRows
13:21 The Algorithm