International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 27 August 2014

YUjuan Li, Wnehua Shen, Huaifu Wang, Peipei Zhou
ePrint Report ePrint Report
Recently, Kalikinkar Mandal and Guang Gong presented a family of nonlinear pseudorandom number generators using Welch-Gong Transformations in their paper [6]. They also performed the cycle decomposition of the WG-NLFSR recurrence relations over different finite fields by computer simulations where the nonlinear recurrence relation is composed of a characteristic polynomial and a WG permutation. In this paper, we mainly prove that the state transition transformation of the WG-NLFSR is an even permutation. We also prove that the number of the cycles in the cycle decomposition of WG-NLFSR is even. And we apply our results to the filtering WG7-NLFSR to prove that the period of the sequences generated by WG7-NLFSR can not be maximum.

Expand

Additional news items may be found on the IACR news page.