Cipher feedback mode , a block cipher mode whereby it s implemented as a self - synchronizing stream cipher 密码反馈方式（ cipher feedback mode ） ，作为自同步序列密码实现的一种分组密码方式。
For meeting the military radio needs , we encrypt the fh system with stream cipher to enhance it ’ s security . it is a good way to guarantee information safety and improve the properties of fh sequences 通过利用序列密码对跳频系统进行加密,可寻求到具有较好密码强度的跳频序列和更为安全的信息传输。
In terms of the difference between encryption key and decryption key , it can be divided into symmetry cryptogram and public key cryptogram , and symmetry can be further divided into block cipher and stream cipher 根据加密密钥和解密密钥性质上的不同，可以将密码体制分为对称密码和公钥密码两大类，而对称密码又包括分组密码和序列密码。
Among the algorithmic design , the corresponding solution to the problems of transforming from the real sequence to binary sequence and precision in the chaotic stream cipher is put forward , and more efficient algorithm and better randomness of key sequence are obtained 在算法的设计中，我们对混沌序列密码所面临的实数序列到二进制序列的转化和精度等问题采取了相应的解决方法，从而获得较高的算法执行效率和良好的密钥序列随机性。
Under finite precision , ways we always seek is easy to implement . and we encrypt the fh system with chaotic stream cipher . simulation results show that the security properties of fh sequence have been improved and the security of information is guaranteed even the fh patterns are broken 大量的对比分析试验表明,该密钥生成器生成的混沌序列密码的密码学特性良好。同时,本文还努力的寻求一种在有限精度条件下混沌加密的可实现方案,并利用混沌序列密码对跳频系统进行加密。
The paper emphasizes on the discussion of the problems in implementation of network speech communication system of pc to pc in lan and the schema of secure network speech communication . the aes algorithm , the chaotic sequence and the method of chaos modulation was adopted to encrypt the voice signal and the srp protocol was used for identity authentication , so as to strengthen security . and some pivotal problems is discussed and settled , such as the compressing , restraining of reverberation and the obliteration of voice signal dither 着重考虑了局域网环境下的pc到pc的网络语音通信系统的实现的相关问题；探讨并设计了网络语音传输中的保密解决方案，采用aes算法、混沌序列密码加密方法和混沌调制方法对语音武汉理工大学硕士学位论文信号进行加密处理，选用srp协议用于身份认证，以提高网络语音通信的保密性能;并针对网络语音传输中的几个关键问题，包括语音信号的压缩、网络语音信号的静音抑止和网络语音的去抖动处理等问题进行了分析。
We discuss the theory and technology of coding and cryptology in the study of information security and information reliability in the disseration . some valuable theoretic results are presented , most of these results are published on the important journey of china , parts of these results are used in some application system . in the design and analysis of error - correcting codes , we obtain the following results 本文探讨了信息安全和信息可靠性研究中的编码密码理论与技术，在纠错码的设计与分析、序列密码的设计与分析以及分组密码的设计与分析等方面，得到了一些有价值的理论结果，大多数结果已在国内核心刊物上发表，有些结果已用于实际的应用系统。
In the design and analysis of sequence cipher , we obtain the following results . first , we give the trace representation of primitive sequences and their corresponding highest lever sequences on galois ring by using the trace function theory and the characteristic of lever factorization , and determine the correlation function linear complexity and element distribution of the highest lever sequences of primitive sequences on galois ring gr ( 4 , m ) 在序列密码的设计和分析方面：首先，利用galois环上迹函数理论和本原序列的权位分解特征，给出了本原序列及其最高权位序列的迹表达式，然后利用galois域上二次型理论与指数和理论决定了特征为4的galois环上本原序列的最高权位的相关函数、线性复杂度和元素分布。
Main contributions of this thesis are as follows : firstly , describe the theory of the hamilton array codes and its general construction . secondly , we construct and program the fast algorithm of hamilton array codes for high dimension and big hamming distance . thirdly , we discussion the design principle of the symmetry ciphers 内容包括：首先论述了hamilton阵列编码的理论和常规构造方法；然后，构造和实现了快速高维大码距hamilton的阵列编码构造算法；接着，探讨了对称密码（包括分组密码和序列密码）的设计原理，最后，结合lfsr和hamilton阵列产生通用密钥编排算法。
In chapter one , the research status quo of the stream cipher including its generation and attacks are introduced , at the same time since the main design idea of the generalized self - shrinking sequences results from that of the shrinking sequences , the research status quo of the shrinking sequence is also presented in this chapter 其中第一章主要介绍了序列密码的研究现状，包括生成现状和攻击现状，另外在本章章末介绍了广义自缩序列设计思想的来源?缩减序列的研究现状。第二章介绍了广义自缩序列族的一些基本伪随机性特性，包括最小周期以及线性复杂度等结果。
