Construction of Odd-Variable Boolean Function with Maximum Algebraic Immunity Using Univariate Polynomial Representation

To protect against algebraic attacks, a high algebraic immunity is now an important criterion for Boolean functions used in stream ciphers. In this paper, a new method based on a univariate polynomial representation of Boolean functions is proposed. The proposed method is used to constmct Boolean functions with an odd number of variables and with maximum algebraic immunity. We also discuss the nonlinearity of the constructed functions. Moreover, a lower bound is deter- mined for the number of Boolean functions with rmximum algebraic immunity.

Construction of Balanced Rotation Symmetric Boolean Functions with Optimal Algebraic Immunity

Algebraic immunity is a new cryptographic criterion proposed against algebraic attacks. In order to resist algebraic attacks, Boolean functions used in many stream ciphers should possess high algebraic immunity. This paper presents one main result to find balanced rotation symmetric Boolean functions with maximum algebraic immunity. Through swapping the values of two orbits of rotation class of the majority function, a class of 4k＋l variable Boolean functions with maximum algebraic immu- nity is constructed. The function f（x） we construct always has terms of degree n-2 independence of what ever n is. And the nonlinearity off（x） is relatively good for large n.

Effect of Kang Ai injection + conventional chemotherapy on tumor markers, apoptotic molecules and immune response in patients with advanced NSCLC

Objective: To study the effects of Kang Ai injection + conventional chemotherapy on tumor markers, apoptotic molecules and immune response in patients with advanced non-small cell lung cancer (NSCLC). Methods: Patients diagnosed as advanced NSCLC in our hospital during March 2015 - October 2017 were randomly divided into the experimental group receiving Kang Ai injection + conventional chemotherapy and the control group receiving conventional chemotherapy. The contents of tumor markers, apoptotic molecules and immunologic cytokines in serum and the contents of immune cells in peripheral blood were determined before and after chemotherapy. Results: after chemotherapy, the content of CEA, CYFRA21-1, SCC-Ag, GDF15 and Livin in the serum of the two groups decreased significantly, and the content of PDCD5, P53 and Bax increased significantly, and the content of CEA, CYFRA21-1, SCC-Ag, GDF15, Livin in the serum of the experimental group were lower than those of the control group, and the content of PDCD5, P53 and Bax were higher than those of the control group;the content of CD3+ and CD4+ cells in peripheral blood and the content of IFN-γ, IL-2 in serum of control group significantly decreased, whereas the content of CD8+ cells in peripheral blood and the content of IL-4, IL-5 in serum significantly increased after chemotherapy;while the content of CD3+ and CD4+ cells in peripheral blood and the content of IFN-γ, IL-2 in serum of experimental group significantly increased, whereas the content of CD8+ cells in peripheral blood and the content of IL-4, IL-5 in serum significantly decreased after chemotherapy. Conclusion: Kang Ai injection + conventional chemotherapy in the treatment of advanced NSCLC can more significantly decrease the serum tumor markers, regulate the secretion of apoptotic molecules and anti-tumor immune response than conventional chemotherapy.

任意偶变元上代数免疫度最优的平衡旋转对称布尔函数的构造

旋转对称布尔函数是一类在输入进行循环移位的条件下输出保持不变的布尔函数.此类函数因具有特殊的结构并且包括许多具有良好密码学性质的布尔函数而在密码学领域受到广泛关注.在代数攻击出现之后,如何构造出具有最优代数免疫度的平衡旋转对称布尔函数成为布尔函数相关研究中的一个热点问题.对于这个问题的研究,在任意奇数变元上已经有了丰富的成果,而在任意偶变元上构造此类函数一直以来都是一件具有挑战性的工作.2021年,Mesnager等人提出了一类构造方法成功解决了这个难题,但所构造函数的非线性度不高.本文在任意偶变元n上给出了一类新的旋转对称布尔函数构造方法,所构造的函数不仅具有最优代数免疫度和平衡性,同时其非线性度在变元个数n大于等于8时均高于现有的任意偶变元上的同类构造.除此之外,通过电脑程序得到了这类新函数在变元个数小于等于16时不仅具有良好的抵抗快速代数攻击的能力而且代数次数可达到最高值n−1或次高值n−2.

Construction of 1-Resilient Boolean Functions with Optimal Algebraic Immunity and Good Nonlinearity

This paper presents a construction for a class of 1-resilient functions with optimal algebraic immunity on an even number of variables. The construction is based on the concatenation of two balanced functions in associative classes. For some n, a part of 1-resilient functions with maximum algebraic immunity constructed in the paper can achieve almost optimal nonlinearity. Apart from their high nonlinearity, the functions reach Siegenthaler＇s upper bound of algebraic degree. Also a class of l-resilient functions on any number n 〉 2 of variables with at least sub-optimal algebraic immunity is provided.

Boolean functions of an odd number of variables with maximum algebraic immunity

In this paper, we study Boolean functions of an odd number of variables with maximum algebraic immunity. We identify three classes of such functions, and give some necessary conditions of such functions, which help to examine whether a Boolean function of an odd number of variables has the maximum algebraic immunity. Further, some necessary conditions for such functions to have also higher nonlinearity are proposed, and a class of these functions are also obtained. Finally, we present a sufficient and necessary condition for Boolean functions of an odd number of variables to achieve maximum algebraic immunity and to be also 1-resilient.

On (2~m + 1)-variable symmetric Boolean functions with submaximum algebraic immunity 2^(m-1)

All (2m +1)-variable symmetric Boolean functions with submaximal algebraic immunity 2m-1 are described and constructed. The total number of such Boolean functions is 32 ·22m-3 +3m-2 · 24 - 2 for m≥2.

On the 2~m-variable symmetric Boolean functions with maximum algebraic immunity

The properties of the 2m-variable symmetric Boolean functions with maximum al- gebraic immunity are studied in this paper. Their value vectors, algebraic normal forms, and algebraic degrees and weights are all obtained. At last, some necessary conditions for a symmetric Boolean function on even number variables to have maximum algebraic immunity are introduced.

A Class of Rotation Symmetric Boolean Functions with Optimum Algebraic Immunity

For an odd integer n ≥ 7, this paper presented a class of n-variable rotation symmetric Boolean functions （RSBFs） with optimum algebraic immunity. The nonlinearity of the constructed functions is determined.

On designated-weight Boolean functions with highest algebraic immunity

Algebraic immunity has been considered as one of cryptographically significant properties for Boolean functions. In this paper, we study ∑d-1 i=0 (ni)-weight Boolean functions with algebraic immunity achiev-ing the minimum of d and n - d + 1, which is highest for the functions. We present a simpler sufficient and necessary condition for these functions to achieve highest algebraic immunity. In addition, we prove that their algebraic degrees are not less than the maximum of d and n - d + 1, and for d = n1 +2 their nonlinearities equalthe minimum of ∑d-1 i=0 (ni) and ∑ d-1 i=0 (ni). Lastly, we identify two classes of such functions, one having algebraic degree of n or n-1.

Construction and enumeration of Boolean functions with maximum algebraic immunity

Algebraic immunity is a new cryptographic criterion proposed against algebraic attacks. In order to resist algebraic attacks, Boolean functions used in many stream ciphers should possess high algebraic immunity. This paper presents two main results to find balanced Boolean functions with maximum algebraic immunity. Through swapping the values of two bits, and then generalizing the result to swap some pairs of bits of the symmetric Boolean function constructed by Dalai, a new class of Boolean functions with maximum algebraic immunity are constructed. Enumeration of such functions is also n given. For a given function p（x） with deg（p（x）） 〈 [n/2], we give a method to construct functions in the form p（x）＋q（x） which achieve the maximum algebraic immunity, where every term with nonzero coefficient in the ANF of q（x） has degree no less than [n/2].

Recent Results on Constructing Boolean Functions with (Potentially) Optimal Algebraic Immunity Based on Decompositions of Finite Fields

Boolean functions with optimal algebraic immunity(OAI functions) are important cryptographic primitives in the design of stream ciphers. During the past decade, a lot of work has been done on constructing such functions, among which mathematics, especially ?nite ?elds, play an important role. Notably, the approach based on decompositions of additive or multiplicative groups of?nite ?elds turns out to be a very successful one in constructing OAI functions, where some original ideas are contributed by Tu and Deng(2012), Tang, et al.(2017), and Lou, et al.(2015). Motivated by their pioneering work, the authors and their collaborators have done a series of work, obtaining some more general constructions of OAI functions based on decompositions of ?nite ?elds. In this survey article, the authors review our work in this ?eld in the past few years, illustrating the ideas for the step-by-step generalizations of previous constructions and recalling several new observations on a combinatorial conjecture on binary strings known as the Tu-Deng conjecture. In fact, the authors have obtained some variants or more general forms of Tu-Deng conjecture, and the optimal algebraic immunity of certain classes of functions we constructed is based on these conjectures.

Some results on the algebraic immunity of Boolean functions

From the motivation of algebraic attacks on stream and block ciphers,the concept of algebraic immunity（AI） of a Boolean function was introduced and studied extensively.High algebraic immunity is a necessary condition for resisting algebraic attacks.In this paper,we give some lower bounds on the algebraic immunity of Boolean functions.The results are applied to give lower bounds on the AI of symmetric Boolean functions and rotation symmetric Boolean functions.Some balanced rotation symmetric Boolean functions with their AI near the maximum possible value「n/2」are constructed.

A Combinatorial Condition and Boolean Functions with Optimal Algebraic Immunity

This paper first proposes an infinite class of 2k-variable Boolean functions with high nonlinearity and high algebraic degree. Then an infinite class of balanced Boolean functions are proposed by modifying the above Boolean functions. This class of balanced Boolean functions have optimal algebraic degree and high nonlinearity. Both classes have optimal algebraic immunity based on a general combinatorial conjecture.

A MATRIX CONSTRUCTION OF BOOLEAN FUNCTIONS WITH MAXIMUM ALGEBRAIC IMMUNITY

Boolean functions used in a cryptographic system should have high algebraic immunity to resist algebraic attacks. This paper presents a matrix method for constructing balanced Boolean functions achieving maximum algebraic immunity.

On Algebraic Immunity of Trace Inverse Functions on Finite Fields of Characteristic Two

The trace inverse functions Tr(λx^(-1)) over the finite field F_(2~n) are a class of very important Boolean functions and are used in many stream ciphers such as SFINKS,RAKAPOSHI,the simple counter stream cipher(SCSC) presented by Si W and Ding C(2012),etc.In order to evaluate the security of those ciphers in resistance to(fast) algebraic attacks,the authors need to characterize algebraic properties of Tr(λx^(-1)).However,currently only some bounds on algebraic immunity of Tr(λx^(-1)) are given in the public literature,for example,the NGG upper bound and the Bayev lower bound,etc.This paper gives the exact value of the algebraic immunity of Tr(λx^(-1)) over F_(2~n),that is,AI(Tr(λx^(-1))) =[2n^(1/2)]- 2,where n ≥ 2,A ∈ F_(2~n) and λ≠ 0,which shows that Dalai's conjecture on the algebraic immunity of Tr(λx^(-1)) is correct.What is more,the authors demonstrate some weak properties of Tr(λx^(-1)) against fast algebraic attacks.

On the construction of odd-variable boolean functions with optimal algebraic immunity

Algebraic immunity is an important cryptographic property of Boolean functions. In this paper, odd-variable balanced Boolean functions with optimal algebraic immunity are obtained by m-sequence and consequently, we get bases with special constructions of vector space. Furthermore, through swapping some vectors of these two bases, we establish all kinds of odd-variable balanced Boolean functions with optimal algebraic immunity.

A NOTE ON TWO CLASSES OF BOOLEAN FUNCTIONS WITH OPTIMAL ALGEBRAIC IMMUNITY

Tu and Deng proposed a class of bent functions which are of optimal algebraic immunity under the assumption of a combinatorial conjecture.In this paper,the authors compute the dual of the Tu-Deng functions and then show that they are still of optimal algebraic immunity under the assumption of the same conjecture.For another class of Boolean functions constructed by Tang,et al.which are of optimal algebraic immunity with similar forms to Tu-Deng functions,the authors show that they are not bent functions by using some basic properties of binary complete Kloosterman sums.

偶变元MAI旋转对称布尔函数

代数免疫度是布尔函数的一个重要密码学指标。给出了具有最大代数免疫度的偶数元旋转对称布尔函数的两种构造方法。进一步地,研究了特殊情形时所构造的旋转对称布尔函数的非线性度,当n≥18时,构造3得到的MAI旋转对称布尔函数的非线性度优于已知构造的偶数元MAI旋转对称布尔函数的非线性度。

基于矢功率谱-AIS的旋转机械故障识别方法研究

结合矢功率谱分析技术和人工免疫系统,提出一种新的机械故障模式识别方法,它以矢功率谱分析为特征提取工具,以aiNet网络为数据压缩工具,以支持向量机为分类器。该方法成功地应用到旋转机械故障诊断中,实验结果表明,该方法是可行和有效的。