计算机密码学中的加密技术研究进展

随着网络信息技术的发展,对网络上传输的数据的安全性要求越来越高,而计算机密码学中的加密技术是保证信息保密性的一种有效手段。文中概括介绍了密码学中的对称密码体制、非对称密码体制和量子密码等三类主要加密技术的相关发展情况,并指出一些值得关注的问题。     

一种混合加密体制的研究与实现

怎样综合利用分组密码和序列密码两种密码体制来得到较高的安全性,如何保证密码分组链接(CBC)方式中IV的安全性,一直是密码学界很关心的问题。提出了一种混合密码体制方案能够较好地解决这些问题,并结合开发实践对整个解决方案进行了详细的阐述。     

A CRYPTOGRAPHER'S WAR MEMORIES

Georgiou [4] proposed a method to strengthen ciphers based on a combination of an enciphering transformation and a multiplication. If the enciphering transformation is a homomorphism and the multiplication in the domain is used in the A cipher and the multiplication in the range is known to the cryptanalyst, his method does not strengthen the cipher at all.     

网吧管理软件密码算法分析与探讨

本文对当前应用广泛的网吧管理软件密码算法系统地进行了分析,指出了以“美萍安全卫士”为代表的一系列国产网吧管理软件加密算法的不足,提出了改进的加密算法,这样将使网络更为安全．     

THE SLIDEX RT CODE

Abstract

In this article, we describe the five block cipher modes of operation that have been approved by the National Institute of Standards and Technology (NIST) for confidentiality. Each mode specifies an algorithm for encrypting/decrypting data sequences that are longer than a single block.     

Format-preserving encryption: Overview and NIST specification

This article reviews the concepts of and motivation for format-preserving encryption (FPE), and then describes three FPE algorithms approved by the National Institute of Standards and Technology (NIST).     

简化轮LBlock的密钥中比特检测及分析

LBlock密码算法是近来提出的一类轻量级分组加密算法。利用LBlock算法的结构特点,结合立方检测的基本思想,设计2个密钥中比特捕获算法,对LBlock算法输出所涉及的密钥比特个数情况进行分析。9轮简化LBlock的每个输出比特全部卷入所有的主密钥比特信息,在18维立方变元下,11轮简化LBlock的输出累加中每个比特全部卷入所有的主密钥比特信息。上述2轮简化LBlock均不存在密钥中比特。研究结果表明,全轮LBlock密码算法具有稳固的密钥信息扩散及混淆性,足以抵抗经典立方攻击。     

基于时空混沌的伪随机数发生器设计

时空混沌系统有很好的密码学特性,但目前基于该模型提出的伪随机数发生器存在效率不高的问题。为此,提出了一种高效的基于时空混沌的伪随机数设计方案。在产生伪随机数的过程中,将一些耗时操作尽可能地替换为一些快速操作,并尽可能地减少时空混沌模型自身的迭代次数,因此算法的效率得到有效提升。对算法所产生的伪随机序列的密码学属性进行了测试,结果表明该伪随机发生器方案不仅运算速度快,而且具有很好的密码学性能。     

How I reconstructed a Spanish cipher from 1591

The present author identified a cipher used in a letter of Alessandro Farnese, Duke of Parma, dated 25 January 1591. It turned out to be similar to known Spanish ciphers of the time in that it is based on simple substitution (with some homophones) and vowel indicator symbols to form syllables systematically. About the same time, the Duke of Mayenne used a much simpler cipher in writing to the same recipient.     

“CRYPTANALYSIS OF THE HAGELIN CRYPTOGRAPH” Wayne G. Barker

Abstract

During the last two centuries, the Mexican diplomatic service produced a huge amount of cryptographic documents. The author has collected, surveyed, and classified nearly 100 since he began to research this subject. In this article, the author shall describe and briefly comment on four different cryptosystems from the first half of the nineteenth century.     

GF(2)上周期为2pn序列的m(s)

给出多项式的若干引理,并对引理进行证明。在此基础上,给出GF(2)上周期序列线性复杂度的表达形式,应用该表达式得出周期N=2pn的二元序列线性复杂度和m(s)之间的关系,其中p是个奇素数,并且2是一个模p2的本源根。结合魏算法,给出2个实例进行证明,结果表明该结果的正确性。     

A survey on the Metaheuristics for Cryptanalysis of Substitution and Transposition Ciphers

This paper presents state-of-art cryptanalysis studies on attacks of the substitution and transposition ciphers using various metaheuristic algorithms. Traditional cryptanalysis methods employ an exhaustive search, which is computationally expensive. Therefore, metaheuristics have attracted the interest of researchers in the cryptanalysis field. Metaheuristic algorithms are known for improving the search for the optimum solution and include Genetic Algorithm, Simulated Annealing, Tabu Search, Particle Swarm Optimization, Differential Evolution, Ant Colony, the Artificial Bee Colony, Cuckoo Search, and Firefly algorithms. The most important part of these various applications is deciding the fitness function to guide the search. This review presents how these algorithms have been implemented for cryptanalysis purposes. The paper highlights the results and findings of the studies and determines the gaps in the literature.     

一种可指定密钥的IDEA加密算法及其实现

提出了一种基于对称性加密原理的可指定密钥加密算法。该算法使得分组的加密密钥可被用户指定,可用于邮件间的信息加密传递。该算法采用Visual C 语言设计,简洁高效,并在某局部网上调试通过。     

THE ADVANCED ENCRYPTION STANDARD

In this paper, we describe the Advanced Encryption Standard (AES), which has been approved after an international competition by the National Institute of Standards and Technology.     

基于RSA公钥密码安全性的研究

RSA是目前最重要的公开密钥密码算法之一。文中介绍了该算法的实现、基本原理等,重点是对其攻击方法和安全性进行分析,相应给出了防止攻击的方法。通过对RSA密码特点以及目前的密码技术发展形势分析,RSA在将来相当一段时期内依旧是应用最广泛的密码算法之一。     

密码学及其在现代通讯中的应用

随着计算技术和网络技术的快速发展,电子商务、电子政务和电子银行应用的普及,信息安全也面临着严峻的考验。而在信息安全领域,密码学占有不可替代的地位。本文主要介绍了常用的对称密码算法、非对称密码算法和Hash函数,最后,介绍了典型的密码算法在现代通讯中的应用。     

AAAS CRYPTO SESSIONS PROCEEDINGS: REVIEW

A simple rotor device is described which can generate two levels of encryption security: periodic encryption to any key length, and random-key encryption. The latter depends on what appears to be a useful and widely-available source of at least pseudorandom numbers: the telephone directory.     

LiCi密码的差分故障攻击

LiCi轻量级分组密码算法是2017年提出的一种新型密码算法,其具有结构微小、消耗能量少等优点,适用于物联网等资源受限的环境。在 LiCi 的设计文档中,对该算法抵御差分攻击和线性攻击的能力进行了分析,但LiCi算法对于差分故障攻击的抵抗能力尚未得到讨论。针对LiCi算法每轮迭代的移位规律,在第31轮迭代时的左半侧多次注入单比特故障,结合其差分性质,可以恢复32 bit长度的轮密钥。根据LiCi算法的密钥编排方案,再对第 30、29、28、27、26 轮迭代进行同样的差分故障攻击,最终可以恢复全部原始密钥。该攻击共需要48个单比特故障,计算复杂度为2³²,说明LiCi算法难以抵抗差分故障攻击。     

混沌自同步序列发生器和数字语音保密通信

提出一种基于自同步序列密码的混沌加密系统，并将产生的混沌序列用于数字语音保密通信，对该混沌序列进行了随机性测试，同时利用计算机网络实现了一个数字语音保密通信试验系统，并取得满意的效果。