I don't know exactly how to find the RC[ 1 ] of 80, or the RC[2] of 30. Can someone explain how to find them?

Here is a picture of the problem I am having with two questions.

S-AES HELP WITH RC constants

  • $\begingroup$ Source of the problem? $\endgroup$
    – kelalaka
    Commented Dec 3, 2018 at 15:46

1 Answer 1


Your question missing some information about the source, however, one can give an answer based on S-AES i.e. Simplified AES.

There is a nice definition of S-AES here.

The Round Constant (RC) or the other name R-con has 10 values for AES and utilized for the key schedule to eliminate the symmetry by making each step of the key schedule slightly different.

i      1   2   3   4   5   6   7   8   9  10
RC[i] 01  02  04  08  10  20  40  80  1B  36

S-AES has defined only 2-rounds, thus the designers of S-AES have to choose only; two RC values. This is just a selection issue, not a generation as in AES-key schedule.

  • RCon[1] = 80
  • RCon[2] = 30

Note: S-AES is only an oversimplified AES for educational use.


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