Paper 2016/572

Faster Evaluation of SBoxes via Common Shares

Jean-Sebastien Coron, Aurelien Greuet, Emmanuel Prouff, and Rina Zeitoun


We describe a new technique for improving the efficiency of the masking countermeasure against side-channel attacks. Our technique is based on using common shares between secret variables, in order to reduce the number of finite field multiplications. Our algorithms are proven secure in the ISW probing model with $n \geq t+1$ shares against $t$ probes. For AES, we get an equivalent of $2.8$ non-linear multiplications for every SBox evaluation, instead of $4$ in the Rivain-Prouff countermeasure. We obtain similar improvements for other block-ciphers. Our technique is easy to implement and performs relatively well in practice, with roughly a 20% speed-up compared to existing algorithms.

Available format(s)
Secret-key cryptography
Publication info
A minor revision of an IACR publication in CHES 2016
Side-channel attacksISW countermeasuremasking.
Contact author(s)
jean-sebastien coron @ uni lu
a greuet @ oberthur com
r zeitoun @ oberthur com
e prouff @ gmail com
2016-06-07: last of 2 revisions
2016-06-03: received
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Creative Commons Attribution


      author = {Jean-Sebastien Coron and Aurelien Greuet and Emmanuel Prouff and Rina Zeitoun},
      title = {Faster Evaluation of SBoxes via Common Shares},
      howpublished = {Cryptology ePrint Archive, Paper 2016/572},
      year = {2016},
      note = {\url{}},
      url = {}
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