0
$\begingroup$

Maximum Distance Separable (MDS) Matrices are used for providing diffusion in a cipher. How to test the strength (with respect to cryptographic properties) of an MDS matrix used in a cipher?

$\endgroup$
  • $\begingroup$ What properties does the cipher need to assume from the MDS matrix? If it's just whether it is, in fact, MDS, well, that's straight-forward to test... $\endgroup$ – poncho Jul 13 '18 at 22:46
  • $\begingroup$ The only strength any matrix can contribute to a cipher is diffusion. Since matrix multiplication is linear. $\endgroup$ – kodlu Jul 14 '18 at 3:33
  • $\begingroup$ @kodlu: however, one could design a cipher which is weak with one specific MDS matrix, and strong with another. Hence, it can be more than just the MDS properties; it can also be how well it plays with the rest of the cipher... $\endgroup$ – poncho Jul 14 '18 at 13:51
  • $\begingroup$ @poncho, could you clarify with an example? I can ask a separate question if you like. I havent seen MDS used differently than in AES, and I thought ( beyond efficiency) any MDS matrix would have the same diffusion/security properties since all MDS codes with the same parameters have the same weight distribution. $\endgroup$ – kodlu Jul 14 '18 at 23:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.