46 research outputs found

    Linear Complexity of Ding-Helleseth Generalized Cyclotomic Binary Sequences of Any Order

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    This paper gives the linear complexity of binary Ding-Helleseth generalized cyclotomic sequences of any order

    Some Notes on Constructions of Binary Sequences with Optimal Autocorrelation

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    Constructions of binary sequences with low autocorrelation are considered in the paper. Based on recent progresses about this topic, several more general constructions of binary sequences with optimal autocorrelations and other low autocorrelations are presented

    Linear Complexity and Autocorrelation of two Classes of New Interleaved Sequences of Period 2N2N

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    The autocorrelation and the linear complexity of a key stream sequence in a stream cipher are important cryptographic properties. Many sequences with these good properties have interleaved structure, three classes of binary sequences of period 4N4N with optimal autocorrelation values have been constructed by Tang and Gong based on interleaving certain kinds of sequences of period NN. In this paper, we use the interleaving technique to construct a binary sequence with the optimal autocorrelation of period 2N2N, then we calculate its autocorrelation values and its distribution, and give a lower bound of linear complexity. Results show that these sequences have low autocorrelation and the linear complexity satisfies the requirements of cryptography

    A General Construction of Binary Sequences with Optimal Autocorrelation

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    A general construction of binary sequences with low autocorrelation are considered in the paper. Based on recent progresses about this topic and this construction, several classes of binary sequences with optimal autocorrelation and other low autocorrelation are presented

    Constructions of Optimal and Near-Optimal Quasi-Complementary Sequence Sets from an Almost Difference Set

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    Compared with the perfect complementary sequence sets, quasi-complementary sequence sets (QCSSs) can support more users to work in multicarrier CDMA communications. A near-optimal periodic QCSS is constructed in this paper by using an optimal quaternary sequence set and an almost difference set. With the change of the values of parameters in the almost difference set, the near-optimal QCSS can become asymptotically optimal and the number of users supported by the subcarrier channels in CDMA system has an exponential growth

    A lower bound on the 2-adic complexity of modified Jacobi sequence

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    Let p,qp,q be distinct primes satisfying gcd(pβˆ’1,qβˆ’1)=d\mathrm{gcd}(p-1,q-1)=d and let DiD_i, i=0,1,⋯ ,dβˆ’1i=0,1,\cdots,d-1, be Whiteman's generalized cyclotomic classes with Zpqβˆ—=βˆͺi=0dβˆ’1DiZ_{pq}^{\ast}=\cup_{i=0}^{d-1}D_i. In this paper, we give the values of Gauss periods based on the generalized cyclotomic sets D0βˆ—=βˆ‘i=0d2βˆ’1D2iD_0^{\ast}=\sum_{i=0}^{\frac{d}{2}-1}D_{2i} and D1βˆ—=βˆ‘i=0d2βˆ’1D2i+1D_1^{\ast}=\sum_{i=0}^{\frac{d}{2}-1}D_{2i+1}. As an application, we determine a lower bound on the 2-adic complexity of modified Jacobi sequence. Our result shows that the 2-adic complexity of modified Jacobi sequence is at least pqβˆ’pβˆ’qβˆ’1pq-p-q-1 with period N=pqN=pq. This indicates that the 2-adic complexity of modified Jacobi sequence is large enough to resist the attack of the rational approximation algorithm (RAA) for feedback with carry shift registers (FCSRs).Comment: 13 pages. arXiv admin note: text overlap with arXiv:1702.00822, arXiv:1701.0376

    Binary linear codes with at most 4 weights

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    For the past decades, linear codes with few weights have been widely studied, since they have applications in space communications, data storage and cryptography. In this paper, a class of binary linear codes is constructed and their weight distribution is determined. Results show that they are at most 4-weight linear codes. Additionally, these codes can be used in secret sharing schemes.Comment: 8 page

    Linear complexity of generalized cyclotomic sequences of order 4 over F_l

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    Generalized cyclotomic sequences of period pq have several desirable randomness properties if the two primes p and q are chosen properly. In particular,Ding deduced the exact formulas for the autocorrelation and the linear complexity of these sequences of order 2. In this paper, we consider the generalized sequences of order 4. Under certain conditions, the linear complexity of these sequences of order 4 is developed over a finite field F_l. Results show that in many cases they have high linear complexity.Comment: Since there is a crucial error in Theorem 1 in the first version, we replace it by the new on

    A lower bound on the 2-adic complexity of Ding-Helleseth generalized cyclotomic sequences of period pnp^n

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    Let pp be an odd prime, nn a positive integer and gg a primitive root of pnp^n. Suppose Di(pn)={g2s+i∣s=0,1,2,⋯ ,(pβˆ’1)pnβˆ’12}D_i^{(p^n)}=\{g^{2s+i}|s=0,1,2,\cdots,\frac{(p-1)p^{n-1}}{2}\}, i=0,1i=0,1, is the generalized cyclotomic classes with Zpnβˆ—=D0βˆͺD1Z_{p^n}^{\ast}=D_0\cup D_1. In this paper, we prove that Gauss periods based on D0D_0 and D1D_1 are both equal to 0 for nβ‰₯2n\geq2. As an application, we determine a lower bound on the 2-adic complexity of a class of Ding-Helleseth generalized cyclotomic sequences of period pnp^n. The result shows that the 2-adic complexity is at least pnβˆ’pnβˆ’1βˆ’1p^n-p^{n-1}-1, which is larger than N+12\frac{N+1}{2}, where N=pnN=p^n is the period of the sequence.Comment: 1

    pp-ary sequences with six-valued cross-correlation function: a new decimation of Niho type

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    For an odd prime pp and n=2mn=2m, a new decimation d=(pmβˆ’1)22+1d=\frac{(p^{m}-1)^{2}}{2}+1 of Niho type of mm-sequences is presented. Using generalized Niho's Theorem, we show that the cross-correlation function between a pp-ary mm-sequence of period pnβˆ’1p^{n}-1 and its decimated sequence by the above dd is at most six-valued and we can easily know that the magnitude of the cross correlation is upper bounded by 4pnβˆ’14\sqrt{p^{n}}-1
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