杂凑函数

A primary motivation for cryptographic hash functions is that they serve as compact representative images of input messages, which they can uniquely identify. For example, the MD5 hash code "72c067b50c90837c95186d019f686700" can be looked on as the "fingerprint" to represent this thesis title uniquely.

密码学杂凑函数也称Hash函数、哈希函数或单向散列函数，它可以将任意长度的消息压缩到固定长度的杂凑值。

A mathematical formula, called a hashing function, is used to produce a unique number that will identify the record's physical location on the disk.

所谓的杂凑函数，是用来制造了一个独特的识别号码，将记录的物理位置在磁盘上。

The smart card system is due to an application of RFID, the first scheme of our research is using this to help store the information of authentications. It uses hashing function combined with smart card to the network authentication for the most part to cut down the cost of computation as well as communication and further accomplish higher security.

智慧卡属於射频辨识的一种应用，本研究的机制一为使用智慧卡系统辅助储存认证用资讯，并采用杂凑函数结合智慧卡的方式来进行网路认证，以降低计算与通讯的成本，并达到高度安全性。

The security of PKI system itself is especially emphasized during the system design and implementation process, which is in accordance with the pervasive characteristic of PKI. Second, the concept of a Trusted Key Management Center is introduced for the first time. This technology greatly strengthens key management practices and allows for smooth transition from PKI to Key Management Infrastructure. Third, certificate status mechanisms are investigated in depth, and a certificate revocation performance simulation system is devised. All these work will provide guides to practice and employment of PKI applications. Based on time constraints, a new taxonomy for authenticated dictionaries is proposed. Fourth, formal analysis ofOCSP protocol is carried out; then an efficient and scalable OCSP system is developed. Fifth, the special requirements caused by the working environments of Wireless PKI are analyzed. Based on communicative hashing and dynamic Merkle hash tree, an efficient certificate status validation method suitable for WPKI is presented. Sixth, one important kind of fair exchange protocols is studied, and a new CEMBS based on RSA cryptosystem is proposed. Afterwards, a novel fair exchange protocol totally based on RSA signature scheme is devised.

在系统设计和实现的过程中，考虑到PKI作为普适性安全基础平台的特点，特别强调PKI系统自身的安全性；第二，首次在PKI系统的设计中提出了"可信密钥管理中心"的概念，这一独特设计大大地强化了密钥管理功能的实施，为PKI向密钥管理基础设施的平滑过渡提供了良好的技术准备；第三，对证书状态验证机制进行了深入研究，设计了证书状态模拟系统，以指导PKI系统和应用的部署和实施；在此基础上，基于时间约束首次给出了认证字典的一种新的分类方法；第四，对OCSP协议进行了形式化分析，设计和实现了一种高效、可扩展的OCSP系统；第五，分析了WPKI工作环境对设计安全基础平台提出的特殊要求，结合无线移动设备的具体特点，基于可交换杂凑函数和动态Merkle杂凑树设计出了一种适用于WPKI环境的高效证书状态查询机制；第六，对一类公平交换协议进行了深入的研究，从设计公平交换协议的密码基础结构出发，提出了一种新型的基于RSA密码体制的高效CEMBS；在此工作的基础上，设计了一种基于RSA密码体制的最优化公平交换协议。

The security of PKI system itself is especially emphasized during the system design and implementation process, which is in accordance with the pervasive characteristic of PKI. Second, the concept of a Trusted Key Management Center is introduced for the first time. This technology greatly strengthens key management practices and allows for smooth transition from PKI to Key Management Infrastructure . Third, certificate status mechanisms are investigated in depth, and a certificate revocation performance simulation system is devised. All these work will provide guides to practice and employment of PKI applications. Based on time constraints, a new taxonomy for authenticated dictionaries is proposed. Fourth, formal analysis of OCSP protocol is carried out; then an efficient and scalable OCSP system is developed. Fifth, the special requirements caused by the working environments of Wireless PKI are analyzed. Based on communicative hashing and dynamic Merkle hash tree, an efficient certificate status validation method suitable for WPKI is presented. Sixth, one important kind of fair exchange protocols is studied, and a new CEMBS based on RSA cryptosystem is proposed. Afterwards, a novel fair exchange protocol totally based on RSA signature scheme is devised.

在系统设计和实现的过程中，考虑到PKI作为普适性安全基础平台的特点，特别强调PKI系统自身的安全性；第二，首次在PKI系统的设计中提出了"可信密钥管理中心"的概念，这一独特设计大大地强化了密钥管理功能的实施，为PKI向密钥管理基础设施的平滑过渡提供了良好的技术准备；第三，对证书状态验证机制进行了深入研究，设计了证书状态模拟系统，以指导PKI系统和应用的部署和实施；在此基础上，基于时间约束首次给出了认证字典的一种新的分类方法；第四，对OCSP协议进行了形式化分析，设计和实现了一种高效、可扩展的OCSP系统；第五，分析了WPKI工作环境对设计安全基础平台提出的特殊要求，结合无线移动设备的具体特点，基于可交换杂凑函数和动态Merkle杂凑树设计出了一种适用于WPKI环境的高效证书状态查询机制；第六，对一类公平交换协议进行了深入的研究，从设计公平交换协议的密码基础结构出发，提出了一种新型的基于RSA密码体制的高效CEMBS；在此工作的基础上，设计了一种基于RSA密码体制的最优化公平交换协议。

Each of these three methods uses a different mathematic background, including one-way hash function, Chinese remainder theorem, and elliptic curve cryptosystem, to ensure the security of the secret key, and to meet the requirements of dynamic management such as solution to problems like adding and deleting groups, modifying relationships among groups, and changing of secret key, etc.

这三种方法分别使用不同的数学背景，包括单向杂凑函数、中国余数定理、以及椭圆曲线密码系统，用以确保秘密金钥的安全性，并且达到动态管理问题的需求，诸如：群组的新增与删除、群组关系的异动、以及更改秘密金钥等问题的解决方案。

At the same time, Biham gave an attack on 40-step SHA-1[6] and Joux improved upon the results of Biham and Chen[5] by presenting practical collisions in SHA-0 [24].The most important result is the break of MD5 by Xiaoyun Wang and Hongbo Yu.

比特追踪法是现今分析MD4系列杂凑函数所使用的最为广泛有效的方法，它的技术细节在2005年欧密会上公开，是破解包含MD5和SHA-1在内的多数MD4系列杂凑算法的理论基础。

A one time password algorithm HTOPC is proposed based on HMAC SHA-1 and a dynamic truncating function.

采用HMAC SHA-1杂凑函数和动态截短函数设计了一次性口令算法HOTP_C。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。