A note on the algebraic immunity of the Maiorana-McFarland class of bent functions

  • Authors:
  • Qichun Wang;Chik How Tan

  • Affiliations:
  • Temasek Laboratories, National University of Singapore, 117411 Singapore, Singapore;Temasek Laboratories, National University of Singapore, 117411 Singapore, Singapore

  • Venue:
  • Information Processing Letters
  • Year:
  • 2012

Quantified Score

Hi-index 0.89

Visualization

Abstract

In Gupta et al. (2011) [5], the authors proved that the algebraic immunity of a subclass of Maiorana-McFarland functions is at most @?n4@?+2 and claimed that this bound is tight. The main theorem of the upper bound is correct. However, their proof is incomplete and the bound is not tight. We will prove a more general theorem of a much larger subclass of Maiorana-McFarland functions and find that its algebraic immunity cannot achieve the optimum value. However, we find an 8-variable Maiorana-McFarland function which is not in that larger subclass of Maiorana-McFarland functions achieving the optimum algebraic immunity (this is the first time that a nontrivial Maiorana-McFarland function with the optimum algebraic immunity is given). Hence, this shows that there exist the Maiorana-McFarland functions achieving the optimum algebraic immunity.