#StackBounty: #aes #block-cipher #algorithm-design #rijndael #diffusion Confusion and Diffusion in the AES functions

Bounty: 50

I am pondering, how each of the four functions that a full AES round does consist of (Add Round Key, Substitute Bytes, Shift Rows and Mix Columns) add to the confusion and diffusion of the full AES.

My understanding would be

  • Add Round Key: Confusion
  • Substitute Bytes: Confusion
  • Shift Rows: Diffusion
  • Mix Columns: Confusion and Diffusion

Is my understanding correct? There are actually two parts, where I am quite unsure:

  • Can confusion be introduced without a secret (subBytes)?
  • Can confusion be introduced from the state alone (Mix Columns)?

I am aware of that and that answer, but they don’t go all the way.

Get this bounty!!!

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