查询词典 cryptanalysis

In the fourth chapter, firstly it introduces the Boolean functions algebraic expressions of the 2-value clock-controlled stop-and-go generator and Gunther generator. It reveals the balanced property of the two kinds of Boolean functions, and studies the Walsh cycle spectrum and the autocorrelation function. It also obtains the coincidence rate of their output sequences with affine sum of some bits of input sequences, and analyzes their ability of resisting the best affine approximation cryptanalysis and differential cryptanalysis. Secondly, we properly present a new definition of the Best Affine Approximation, namely BAA on the Boolean vector functions, followed by the spectral characteristic of such defined BAA attacks through using the decomposition formula of the union distribution for random variables. A lower bound of such BAA attacks is proposed. Finally, we also study the spectral characteristic of the second kind of nonlinearity of Boolean vector functions, followed by a higher bound of such nonlinearity. Furthermore, the limited relationship between the second kind of nonlinearity of Boolean vector functions and the linear structure of the linear combination of every component is analyzed.

在第四章中，首先给出了2值密钥流"停走生成器"和"衮特生成器"中实际存在的布尔函数的代数表示，揭示了这两类布尔函数的平衡性，随后研究了它们的Walsh循环谱和自相关函数等，得到了它们的输出序列与输入序列中的某些bit的仿射项的符合率，分析了它们抵抗最佳仿射逼近攻击和差分攻击的能力；其次，我们合理地给出了布尔向量函数最佳仿射逼近的新定义，利用布尔随机变量联合分布的分解式考察了相应的谱特征，并给出了布尔向量函数与其最佳仿射逼近的符合率的一个下界；最后，我们还考察了布尔向量函数第二类非线性度的谱特征，给出了布尔向量函数第二类非线性度的一个上界，并揭示了布尔向量函数第二类非线性度与其各个分量的线性和的线性结构之间存在的制约关系。

As a variant of differential cryptanalysis, impossible differential cryptanalysis is a simple and effective technique, and it is also one of the most frequently used cryptanalytic methods.

不可能差分分析作为差分分析的一种变体，是一种简单有效的密码分析方法，也是目前最常用的密码分析方法之一。

Active attack cryptanalysis based and fully scalable FGS encryption algorithm Aimed to the weakness of the current selective encryption algorithms in the sense of cryptanalysis, we design a active spacial—temporal correlation attack scheme and propose a both encryption strategies on base-layer and enhancement-layer. Not only the general FGS stream encryption is dealt with but also the case of FGST (fine granularity sealable temporal) is also well addressed.

2基于主动攻击安全的充分可扩展FGS加密算法针对目前压缩视频流加密算法所经常采用的选择加密方法，通过进行主动时域、空域相关性攻击，指出该类算法存在的问题，包括对于FGS基本层单独加密的安全分析，然后设计实现了基本层和增强层同时加密的安全策略，为保证FGS充分可扩展功能，算法同时还支持细粒度时域可扩展编码FGST(fine granularity scalable temporal)的情况。

When we make use of linear cryptanalysis method, finding the best linear approximation of the encrypting algorithm is very important.

在线性密码分析方法中，寻找加密算法的最佳线性逼近是很关键的一步。

The cryptanalysis and design of block ciphers are one of the hotspots in modern cryptography.

分组密码的设计与分析是当前密码学研究的热点课题之一。

An important problem in the design of the block cipher is to improve the performance of the resisting differential cryptanalysis.

在分组密码的设计中，提高分组密码的抗差分攻击性能是一个重要的课题。

This is a dedicated machine cryptanalysis in World War II has been applied.

这是一种专用的密码分析机，在第二次世界大战中得到了应用。

Cryptanalysis is the base of information security, and all applications are constructed on it.

但是这也带来信息的安全性问题。

Experiments show that this cryptanalysis is feasible and efficient.

该文还讨论了一些可能采取的改进措施及其效果。

Design and cryptanalysis on group signature is always the hotspot in the field of cryptography.

对群签名的设计与分析始终是密码学领域的一大热点。

Fostering the concept of multi-culture firmly and mastering the development of advanced culture correctly are conductive to resisting terrorism, separatism of nationalities and ultraism of religion, which is of great academic theoretical, immediate and profound historical si...

牢固树立多元文化的理念和正确把握先进文化的发展方向，有助于在世界范围内自觉地抵制恐怖主义，民族分裂主义和宗教极端主义。不仅具有重大的学术理论意义，而且也具有重大的现实意义和深远的历史意义。

But if anyone walks in the night, he stumbles, because the light is not in him.

11：10 若在黑夜行走，就必碰跌，因为那光不在他里面。