Paper 2007/366

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

Jintai Ding, Bo-Yin Yang, Chen-Mou Cheng, Owen Chen, and Vivien Dubois


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.

Available format(s)
Public-key cryptography
Publication info
Published elsewhere. multivariate public key cryptography,differential, symmetry, projection
Contact author(s)
ding @ math uc edu
2007-09-13: received
Short URL
Creative Commons Attribution


      author = {Jintai Ding and Bo-Yin Yang and Chen-Mou Cheng and Owen Chen and Vivien Dubois},
      title = {Breaking the Symmetry: a Way to Resist the New Differential Attack},
      howpublished = {Cryptology ePrint Archive, Paper 2007/366},
      year = {2007},
      note = {\url{}},
      url = {}
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