基于类型的密码协议验证方法

探讨使用一组形式化的规则来验证密码协议安全属性的方法.这些规则基于传统的等级和信息流的思想,通过将其扩展后用来处理密码协议中的并发进程.通过这些规则可以向用户提供一种检测方法,该方法用于判断:如果协议通过了检测,则可以认为该协议没有泄漏任何秘密的消息.     

分析安全协议密码系统相关缺陷的模态逻辑方法

安全协议未采用适当的密码系统来实现，会使最终的安全协议存在密码系统相关缺陷．对该类缺陷进行形式化分析时，不能使用完善的密码系统假设，这是安全协议形式化分析研究中的一个难点,以CKT5逻辑为基础，以对称密码算法为重点，将序列密码算法和分组密码算法的特性，以逻辑推理规则的形式引入到CKT5逻辑框架中，使得扩展后的逻辑能够用于分析安全协议密码系统相关缺陷,并用实例说明了如何使用扩展逻辑来分析密码系统相关缺陷.     

公钥密码体制下认证协议的形式化分析方法研究

本文通过对形式化方法中最广泛使用的类BAN逻辑进行研究发现，此方法更侧重于对称密码体制下认证协议的分析，而在分析基于公钥体制的认证协议时，该方法有很大的局限性。因此，文中针对公角密码的特点对类BAN逻辑进行了扩展。扩展后的逻辑方法能够更好地应用于分析公钥认证协议。     

基于串空间模型的电子商务协议的形式化分析

采用形式化方法分析安全协议是协议分析的有效手段,近年来,出现了众多的研究方法。串空间模型是一种新兴的密码协议形式化分析工具。文章基于串空间模型,扩展了认证测试方法,使之能够描述和分析电子商务协议。并用该方法对一个具体的协议进行了形式化分析,得到了与以往文献相同的结论。     

基于图元的事件图生成算法

与单轮运行情形不同，多轮并发运行的密码协议存在更为复杂的安全性问题。并发运行密码协议的形式化分析对象包括密码协议的多轮并发运行和多个密码协议的并发运行两种情形，且二者具有统一的形式化模型。基于扩展的串空间模型和Spi演算理论，提出用于并发运行密码协议安全属性验证的事件图模型。图元是事件图的构造单元，它满足消息事件之间的通信关系和前驱关系约束以及消息语句的新鲜性约束。定义消息事件之间、图元之间以及消息事件和图元之间的前缀、组合和选择运算，并给出事件图生成算法。     

一种基于问题求解理论的密码协议形式模型

提出了一种基于问题求解理论的密码协议模型，给出了模型的基本语法以及基于ρ演算的形式语义，明确了模型推理过程中涉及到的一些关键性的概念和命题。该模型具有以下特点：能够对密码协议进行精确的形式化描述；具有合理可靠的可证明语义；对密码协议安全性的定义精确合理；便于实现自动化推理。所有这些均确保了基于该模型的密码协议安全性分析的合理性和有效性，为正确的分析密码协议的安全性提供了可靠依据。     

密码协议安全性证明系统解析器的设计与实现*

可证明安全性是密码协议安全性评估的重要依据,但手写安全性证明容易出错且正确性难以判定,利用计算机辅助构造游戏序列进而实现自动化证明是当前一种可行的方法。为此提出一种基于进程演算的密码协议形式化描述模型,定义了描述密码协议安全性证明中攻击游戏的语法规则,并借助工具LEX和YACC,设计出解析器程序,将密码协议及其安全性的形式化描述解析为自动化安全性证明系统的初始数据结构,并用实例来说明这种方法的可行性。     

适应受限环境的认证协议及其SVO逻辑分析

针对认证协议在受限通信网络环境中的应用和安全问题,提出一种基于椭圆曲线密码技术的认证协议,使用对称密码为协议中的交互信息提供机密性,在协议最后生成参与者共享的会话密钥。采用扩展的SVO逻辑对推荐协议进行形式化分析,结果证明该协议的安全性符合要求。     

用BAN逻辑方法分析TLS协议

密码协议的形式化正在成为国际上研究的热点，通过形式化分析密码协议来判断密码协议是否安全可靠。BAN逻辑是最早提出、最为重要的一种安全协议分析方法，被广泛地用于密码协议的安全性证明。文章介绍了BAN逻辑和TLS协议，用BAN逻辑分析TLS协议，从而证明TLS协议的双方认证协议是完整的、没有漏洞的。     

一种新的共享密钥安全协议设计方法

为了设计出具有高安全性的安全协议，提出了一种面向主体的逻辑，可以形式化和系统地设计共享密钥安全协议；根据可以提供的不同安全服务，将密码机制抽象为不同信道，这样在设计安全协议时不必考虑密码机制的实现细节；提出安全协议的转发设计规则，将设计规则作为预防攻击的有效措施；运用该逻辑和设计规则设计了一种新的共享密钥安全协议，该协议能达到相互身份认证和密钥分发目的，并能预防与设计规则相对应的攻击。     

An Integrated View on Rules and Principles

In the law, it is generally acknowledged that there are intuitive differences between reasoning with rules and reasoning with principles. For instance, a rule seems to lead directly to its conclusion if its condition is satisfied, while a principle seems to lead merely to a reason for its conclusion. However, the implications of these intuitive differences for the logical status of rules and principles remain controversial.A radical opinion has been put forward by Dworkin (1978). The intuitive differences led him to argue for a strict logical distinction between rules and principles. Ever since, there has been a controversy whether the intuitive differences between rules and principles require a strict logical distinction between the two. For instance, Soeteman (1991) disagrees with Dworkin's opinion, and argues that rules and principles cannot be strictly distinguished, and do not have a different logical structure.In this paper, we claim that the differences between rules and principles are merely a matter of degree. We give an integrated view on rules and principles in which rules and principles have the same logical structure, but different behavior in reasoning. In this view, both rules and principles are considered to consist of a condition and a conclusion. The observed differences between rules and principles are, in our view, the result of different types of relations that they have with other rules and principles. In the integrated view, typical rules and typical principles are the extremes of a spectrum.We support our claim by giving an explicit formalization of our integrated view using the recently developed formal tools provided by Reason-Based Logic. As an application of our view on rules and principles, we give three ways of reconstructing reasoning by analogy.     

含序信息的粗集方法研究

经典粗集理论给出了不可识别、上近似、下近似、简式和核等概念，其核心思想是运用条件属性集导致的知识粒子来近似决策属性集导致的知识粒子，进而推导出规则。这些知识粒子的实质是根据存在于属性值问的等价关系得到的，而事实上可能存在某些属性，其属性值内部存在序关系，与其它某属性间存在语义关系，这样的属性称为标准。本文所研究的粗集方法，考虑标准所携带的这些信息，推导出含有序信息的规则，并探讨使推导的规则更加完全和一致。本文给出了含序粗集方法（CORS）的定义、数据分析以及规则生成方法，并提出了一种更加合理的质量近似公式以及生成规则的四条原则。     

A theory of legal reasoning and a logic to match

This paper describes a model of legal reasoning and a logic for reasoning with rules, principles and goals that is especially suited to this model of legal reasoning. The paper consists of three parts. The first part describes a model of legal reasoning based on a two-layered view of the law. The first layer consists of principles and goals that express fundamental ideas of a legal system. The second layer contains legal rules which in a sense summarise the outcome of the interaction of the principles and goals for a number of case types. Both principles, goals and rules can be used in legal arguments, but their logical roles are different. One characteristic of the model of legal reasoning described in the first part of the paper is that it takes these logical differences into account. Another characteristic is that it pays serious attention to the phenomena of reasoning about the validity and acceptance of rules, respectively principles and goals, and about the application of legal rules, and the implications of these arguments for the use of rules, principles and goals in deriving legal conclusions for concrete cases.The second part of the paper first describes a logic (Reason-Based Logic) that is especially suited to deal with legal arguments as described in terms of the previously discussed model. The facilities of the logic are illustrated by means of examples that correspond to the several aspects of the model.The third part of the paper deals with a number of logico-philosophical reflections on Reason-Based Logic. The occasion is also used to compare these presuppositions with theories of defeasible reasoning based on the comparison of arguments.The ideas developed in this paper are based on the draft of my book Reasoning with rules which will be published by Kluwer Academic Publishers in the Law and Philosophy Series. The book offers not only more elaborate and sometimes different treatments of the topics of this paper, but also pays more attention to the philosophical background of this work.     

Rules and Principles in Legal Reasoning. A Study of Vagueness and Collisions in Artificial Intelligence and Law

There is a difference between rules and principles in Law Argumentation Theory. The conflict of rules is solved by meta-rules like Lex Superior (based in general hierarchical structure of legal system), Lex Posterior (based on later rule priority), Lex Specialis (based on specification of rules) and also by exceptions, which exclude the conflict. The collisions of rules imply the validity negation of one rule. However, this does not occur in a collision of principles. Even when one principle is not applied by collisions, its validity remains. Another point is that the priority could change, changing the overridden principle. So, it is necessary to build a reasoning model that allows reasoning with conflicting legal principles. Another problem is vagueness of principles. Vagueness does not mean just an imprecise meaning, linguistically talking. There should be attributed a semantic, or a pragmatic meaning. Vagueness of principles occurs on account of its opened antecedent, with no established conduct. In this paper a model of reasoning using Artificial Intelligence (AI) & Law methods is described aiming at treating vagueness and collisions of principles, searching to establish rationality in legal argumentation systems.     

Iptables防火墙性能优化研究

研究Linux下Netfilter/Iptables防火墙的实现机制,分析影响防火墙性能的关键因素,提出防火墙优化的概念,并给出几点规则组织的原则,按照此原则编制优化后防火墙规则的模板,最后讨论优化后取得的效果。     

规则库冗余性控制策略的研究

冗余性控制是研究知识库组织、管理和维护中的一个问题．本文通过对智能型机译系统中规则知识表示方法的分析，提出了将冗余规则划分为显式冗余规则和隐式冗余规则分别予以处理的思想，给出了显式冗余规则的判别算法和部分隐式冗余规则的检测标准，并提出了控制机译系统规则库冗余性的基本原则.     

The application of certainty factors to neural computing for rulediscovery

Discovery of domain principles has been a major long-term goal for scientists. The paper presents a system called DOMRUL for learning such principles in the form of rules. A distinctive feature of the system is the integration of the certainty factor (CF) model and a neural network. These two elements complement each other. The CF model offers the neural network better semantics and generalization advantage, and the neural network overcomes possible limitations such as inaccuracies and overcounting of evidence associated with certainty factors. It is a major contribution of the paper to show mathematically the quantizability nature of the CFNet since previously the quantizability of the CF model was demonstrated only empirically. The rule discovery system can be applied to any domain without restriction on both the rule number and rule size. In a hypothetical domain, DOMRUL discovered complex domain rules at a considerably higher accuracy than a commonly used rule-learning program C4.5 in both normal and noisy conditions. The scalability in a large domain is also shown. On a real data set concerning promoters prediction in molecular biology, DOMRUL learned rules with more complete semantics than C4.5.     

汉语文本中交集型切分歧义的分类处理

自动分词是中文信息处理的基本问题，交集型歧义字段的切分又是中文分词的难点．本文把交集型歧义字段按其宏结构分类，再依据本文提出的4条切分原则，使用歧义字段的结构信息和语法规则对不同类型的交集字段分别处理，提高了分词的准确性．该分词方法已作为中文网页索引和检索工具被用于网络搜索引擎中．实验效果表明，这一分词系统能够处理某些其它分词系统不能正确划分的实例．     

扩充与缺省规则的简化和分类

文章从缺省理论扩充的定义出发,在求扩充前根据缺省规则的特征,把对计算扩充没有影响的规则不予考虑,同时把具有不相容判断的规则分开考虑,也即就是在求扩充前对缺省规则进行适当的简化和分类,通过分析讨论给出了若干简化和分类的原则,从而使计算得以简化。     

多步原子规则的大规模关联分类

关联分类已成为数据挖掘研究的热点问题之一.为解决大规则关联分类问题,本文提出了基于原子规则的多步分类方案,并对作者提出的多步原子关联规则分类新技术进行了深入的理论研究.与同类关联分类方法(如CBA)比较,本文提出的方法具有学习速度快、分类准确度高的优点.