Sequences, Bent functions and Jacobsthal sums

  • Authors:
  • Tor Helleseth;Alexander Kholosha

  • Affiliations:
  • The Selmer Center, Department of Informatics, University of Bergen, Bergen, Norway;The Selmer Center, Department of Informatics, University of Bergen, Bergen, Norway

  • Venue:
  • SETA'10 Proceedings of the 6th international conference on Sequences and their applications
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

The p-ary function f(x) mapping GF(p4k) to GF(p) and given by f(x) = Tr4k(axd + bx2) with a, b ∈ GF(pp4k) and d = pp3k + p2k - pk + 1 is studied with the respect to its exponential sum. In the case when either apk(pk+1) ≠ apk+1: or a2 = bd with b ≠ 0, this sum is shown to be three-valued and the values are determined. For the remaining cases, the value of the exponential sum is expressed using Jacobsthal sums of order pk + 1. Finding the values and the distribution of those sums is a long-lasting open problem.