English

On the primitivity of the AES-128 key-schedule

Group Theory 2022-02-16 v3 Cryptography and Security

Abstract

The key-scheduling algorithm in the AES is the component responsible for selecting from the master key the sequence of round keys to be xor-ed to the partially encrypted state at each iteration. We consider here the group Γ\Gamma generated by the action of the AES-128 key-scheduling operation, and we prove that the smallest group containing Γ\Gamma and all the translations of the message space is primitive. As a consequence, we obtain that no proper and non-trivial subspace can be invariant under its action.

Keywords

Cite

@article{arxiv.2103.06169,
  title  = {On the primitivity of the AES-128 key-schedule},
  author = {Riccardo Aragona and Roberto Civino and Francesca Dalla Volta},
  journal= {arXiv preprint arXiv:2103.06169},
  year   = {2022}
}