International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Breaking the Symmetry: a Way to Resist the New Differential Attack

Jintai Ding
Bo-Yin Yang
Chen-Mou Cheng
Owen Chen
Vivien Dubois
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Abstract: Sflash had recently been broken by Dubois, Stern, Shamir, etc., using a differential attack on the public key. The $C^{\ast-}$ signature schemes are hence no longer practical. In this paper, we will study the new attack from the point view of symmetry, then (1) present a simple concept (projection) to modify several multivariate schemes to resist the new attacks; (2) demonstrate with practical examples that this simple method could work well; and (3) show that the same discussion of attack-and-defence applies to other big-field multivariates. The speed of encryption schemes is not affected, and we can still have a big-field multivariate signatures resisting the new differential attacks with speeds comparable to Sflash.
  title={Breaking the Symmetry: a Way to Resist the New Differential Attack},
  booktitle={IACR Eprint archive},
  keywords={public-key cryptography /},
  note={multivariate public key cryptography,differential, symmetry, projection 13769 received 13 Sep 2007},
  author={Jintai Ding and Bo-Yin Yang and Chen-Mou Cheng and Owen Chen and Vivien Dubois},