S-boxes Analysis

[antonyef]

How can we calcuate cryptographic properties ( difference distribution table, linear approximation table,....) of S-boxes using claasp ?

[juaninf]

Thanks for your question. CLAASP is built on top of SAGE. One option to check the cryptographic properties of S-boxes is to use the SBox module from SAGE. You can obtain the DDT (Difference Distribution Table) of the S-Box of Gaston by doing the following:

from sage.crypto.sbox import SBox
ddt = SBox([0, 5, 10, 11, 20, 17, 22, 23, 9, 12, 3, 2, 13, 8, 15, 14,
        18, 21, 24, 27, 6, 1, 4, 7, 26, 29, 16, 19, 30, 25, 28, 31]).difference_distribution_table()
print(ddt)

[antonyef]

your reply was very helpful. How to check Strict Avalanche Criterion (SAC) of a S-box?