共查询到20条相似文献,搜索用时 15 毫秒
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基于AES和DES算法的可重构S盒硬件实现 总被引:5,自引:0,他引:5
密码芯片的可重构性不仅可以提高安全性,而且可以提高芯片适应性.S盒是很多密码算法中的重要部件,其可重构性对密码芯片的可重构性有重大影响.文章在分析AES和DES算法中S盒硬件实现方法的基础上,利用硬件复用和重构的概念和相关技术,提出了一种可重构S盒(RC-S)结构及其实现方法.实验结果表明RC-S可用于AES算法和DES的硬件实现.基于RC-S的AES、DES密码模块规模分别是AES、DES模块的0.81/1.13,性能分别是DES/AES的0.79/0.94. 相似文献
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为提高高级加密标准(advanced encryption standard,AES)算法的安全性,提出了一种新的S盒生成方案。在分析了现有S盒存在的问题后,基于S盒的构造原理和密码学性质,通过选择新的不可约多项式和仿射变换对,同时调整仿射变换与乘法逆的运算顺序,构造出一种新的S盒;对生成的新S盒与AES 的S盒以及其他改进S盒在代数式项数、严格雪崩标准距离等方面进行了比较,结果显示新S盒具有更好的代数性质,能够有效抵御代数攻击;还对新S盒进行了硬件设计并优化,DC综合结果显示新S盒复域优化实现消耗的资源比传统复域实现少12%,比查找表法实现少41%。新S盒在安全性方面优于现有S盒,将其应用于AES软件设计和硬件设计,并通过仿真测试验证了其正确性。 相似文献
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S盒是分组密码算法中的关键部件之一,其混淆和置乱作用决定着整个密码算法的安全强度。为使基于混沌系统生成的S盒具有更好的密码学性能,提出了一种基于抗退化混沌系统的动态S盒设计方案。首先,使用Lorenz混沌映射扰动Chebyshev混沌映射;然后,使用截取位数法和划分区间法生成两种初始S盒;最后,使用索引排序扰乱法得到最终S盒。所提抗退化混沌系统生成的混沌序列不存在短周期现象,具有遍历性、不可预测性等特点;运用于S盒的设计中能极大提升S盒的安全性能,消除混沌生成源的安全隐患;并且,通过对系统参数的调控可批量地生成动态S盒。对S盒的安全性能,即非线性度、差分均匀性、严格雪崩准则、输出比特间独立性和双射特性进行了测试和对比,实验结果表明,所提方案生成的S盒具有更好的密码学性能,可用于分组密码算法的设计中。 相似文献
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Sheng Gao Wenping Ma Zepeng Zhuo Fenghe Wang 《Frontiers of Computer Science in China》2011,5(4):448-453
Substitution boxes (S-boxes) are often used as the most important nonlinear components in many symmetric encryption algorithms.
The cryptographic properties of an S-box directly affect the security of the whole cipher system. Recently, generalized global
avalanche characteristics (GGAC) were introduced to measure the correlation between two arbitrary Boolean functions. In this
paper, to better evaluate the security of an S-box, we present two cross-correlation indicators for it. In addition, by studying
the related properties of the cross-correlation between two balanced Boolean functions, we propose the lower bounds on the
sum-of-squares indicator related to GGAC for two balanced functions and also for an S-box. 相似文献
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S盒是分组密码算法中唯一的非线性部件,设计一个性能良好的S盒具有重要的实际意义。本文提出了一种新的S盒构造方法,算法中利用两个混沌系统进行迭代,操作简单却大大增加了置乱效果。文中分析了S盒的密码学性能,包括双射特性,非线性度,严格雪崩准则,输出比特间独立性,差分概率和线性概率,最后在我们提出的S盒的Lyapunov指数定义的基础上,计算了本文构造的S盒的Lyapunov指数,结果表明该方法生成的S盒具有良好的密码学性质。 相似文献
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置换盒又被称为S盒,是分组密码中常采用的重要部件。在分析S盒性能评价指标的基础上,提出了一种基于时空混沌的S盒产生方法。仿真测试表明根据该方法,可以产生一批具有良好性能的S盒,为开发新的分组密码算法奠定了很好的基础。 相似文献
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满足若干密码学性质的S-盒的构造 总被引:15,自引:0,他引:15
S-盒是许多密码算法的唯一非线性部件,它的密码强度决定了整个密码算法的安全强度.但 是对于大的S-盒的构造比较困难,而且软硬件实现也比较难,目前比较流行的是8×8的S-盒 .基于m-序列,提出一种构造8×8与8×6的S-盒的方法,通过测试法从中选出了一批非线性 性质与差分均匀性都比较好的S-盒.同时,基于正形置换构造了一批4×4的S-盒.这些S-盒 对进一步设计密码算法提供了非线性资源. 相似文献
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Computational aspects of the expected differential probability of 4-round AES and AES-like ciphers 总被引:1,自引:0,他引:1
Joan Daemen Mario Lamberger Norbert Pramstaller Vincent Rijmen Frederik Vercauteren 《Computing》2009,85(1-2):85-104
In this paper we study the security of the Advanced Encryption Standard (AES) and AES-like block ciphers against differential cryptanalysis. Differential cryptanalysis is one of the most powerful methods for analyzing the security of block ciphers. Even though no formal proofs for the security of AES against differential cryptanalysis have been provided to date, some attempts to compute the maximum expected differential probability (MEDP) for two and four rounds of AES have been presented recently. In this paper, we will improve upon existing approaches in order to derive better bounds on the EDP for two and four rounds of AES based on a slightly simplified S-box. More precisely, we are able to provide the complete distribution of the EDP for two rounds of this AES variant with five active S-boxes and methods to improve the estimates for the EDP in the case of six active S-boxes. 相似文献
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著名的Rijndael(AES)以及Hierocrypt-L1密码算法都采用了有限域GF(2m)上一类置换作为S盒,这些S盒具有良好的差分/线性特性和比较复杂的代数结构。文章给出该类S盒的构造通式,并详细讨论和分析了这类S盒的差分/线性特性、代数结构与域上的生成多项式、使用的仿射变换以及幂次数之间的深刻关系。这对以后设计有限域上的同类S盒有一定的指导作用。 相似文献
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随着物联网的发展,轻量级分组密码算法的设计显得尤为重要。S盒是对称密码算法的关键部件。许多加密算法的硬件实现过程易受侧信道攻击,门限实现是一种基于秘密共享和多方计算的侧信道攻击对策。通过简单地对三次布尔函数中的变量进行循环移位,构建密码性质最优的4×4安全轻量S盒,并且为所构造的S盒设计了门限实现方案来抵御侧信道攻击,该方案是可证安全的。该方法构造的S盒的四个分量函数的实现电路相同,极大地降低了硬件实现的复杂度。给定S盒的一个分量,其余的三个分量可通过该分量的循环移位获得,这样大大降低硬件实现成本,易于快速软件实现。 相似文献
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Emad Mossa 《International Journal of Speech Technology》2017,20(1):163-169
This paper introduces a secure speech communication approach, which is based on encryption and authentication. This system is based on Advanced Encryption Standard (AES) for encryption and private image database for enhancement of encryption and for authentication. The idea of this cryptosystem is based on XOR of one image from image database with the clear speech before encryption and embedding the index number of this image in the database as a least significant bit watermark into speech. A comparison study is held between the AES block cipher algorithm and the proposed algorithm. This proposed cryptosystem used to enhance the security of AES algorithm and increase its immunity to brute force attacks. It used also to provide authentication and enhance security by addition of extra key which don’t need to be exchanged between parts depending on the embedded image. The extra proposed step remove residual intelligibility from clear speech and fill the silent periods within speech conversation and help in destroy format and pitch information. Security analyses are presented for the proposed cryptosystem from a strict cryptographic viewpoint. Experimental results verify and prove that the proposed cryptosystem is highly secure from the cryptographic viewpoint. 相似文献
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通过对分组密码安全性设计的分析,针对DES分组密码的不足进行改进,设计了一种基于非S盒变换的变种DES,用随机数产生S盒的排列顺序,通过对密钥和S盒顺序的交替移位,使所有的明文采用不同的密钥加密或不同的S盒处理,任意两组相同的明文加密后都会产生不同的密文,从而实现牢不可破的"一次一密"的密码体制. 相似文献
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In the paper we use recently proposed cellular automata (CA) based methodology (Szaban and Seredynski in LNCS, vol. 5191,
pp. 478–485, 2008) to design the 6×4 S-boxes functionally equivalent to S-boxes used in current cryptographic standard known as Data Encryption
Standard (DES). We provide an exhaustive experimental analysis of the proposed CA-based S-boxes in terms of non-linearity,
autocorrelation, balance and strict avalanche criterion, and compare results with ones corresponding to DES S-boxes. We show
that the proposed CA-based S-boxes have cryptographic properties comparable to or better than classical S-box tables. The
interesting feature of the proposed S-boxes is a dynamic flexible structure fully functionally realized by CA, while the classical
DES S-boxes are represented by predefined unchangeable table structures. 相似文献
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S盒是许多分组密码唯一的非线性部件,它的密码强度决定了整个密码算法的安全强度.足够大的S盒是安全的,但为了便于实现,分组密码多采用若干小S盒拼凑.针对一类分组密码算法,通过将S盒与密钥相关联,给出了S盒重组算法,丰富了S盒的应用模式,有效提高了分组密码的安全强度. 相似文献