Sunghwan KIM Gang-Mi GIL Jong-Seon NO
In this paper, a new class of bent functions is constructed by combining class M and class C bent functions. Using the construction method of the class D bent functions defined on the binary vector space, new p-ary generalized bent functions are also introduced for odd prime p.
Young-Sik KIM Ji-Woong JANG Jong-Seon NO Tor HELLESETH
In this paper, using p-ary bent functions defined on vector space over the finite field Fpk, we generalized the construction method of the families of p-ary bent sequences with balanced and optimal correlation properties introduced by Kumar and Moreno for an odd prime p, called generalized p-ary bent sequences. It turns out that the family of balanced p-ary sequences with optimal correlation property introduced by Moriuchi and Imamura is a special case of the newly constructed generalized p-ary bent sequences.
Shinya MATSUFUJI Naoki SUEHIRO
This paper discusses factorization of bent function type complex Hadamard matrices of order pn with a prime p. It is shown that any bent function type complex Hadamard matrix has symmetrical factorization, which can be expressed by the product of n matrices of order pn with pn+1 non-zero elements, a matrix of order pn with pn non-zero ones, and the n matrices, at most. As its application, a correlator for M-ary spread spectrum communications is successfully given, which can be simply constructed by the same circuits with reduced multiplicators, before and behind.
Shinya MATSUFUJI Naoki SUEHIRO Noriyoshi KUROYANAGI
This paper presents a quadriphase sequence pair, whose aperiodic auto-correlation functions for non-zero shifts and cross-one for any shift take pure imaginary values. Functions for pairs of length 2n are formulated, which map the vector space of order n over GF(2) to Z4. It is shown that they are bent for any n, such that their Fourier transforms take all the unit magnitude.
In this paper we study n-input m-output Boolean functions (abbr. (n,m)-functions) with high nonlinearity. First, we present a basic construction method for a balanced (n,m)-function based on a primitive element in GF(2m). With an iterative procedure, we improve some lower bounds of the maximum nonlinearity of balanced (n,m)-functions. The resulting bounds are larger than the maximum nonlinearity achieved by any previous construction method for (n,m)-functions. Finally, our basic method is developed to construct an (n,m)-bent function and discuss its maximum algebraic degree.
Shinya MATSUFUJI Kyoki IMAMURA
It is known that a family of p-ary bent sequences, whose elements take values of GF (p) with a prime p, possesses low periodic correlation properties and high linear span. Firstly such a family is shown to consist of balanced sequences in the sense that the frequency of appearances in one period is the same for each nonzero element and once less for zero element. Secondly the exact distribution of the periodic correlation values is given for the family.