Kleene Algebra and Bytecode Verification

Most standard approaches to the static analysis of programs, such as the popular worklist method, are first-order methods that inductively annotate program points with abstract values. In [6] we introduced a second-order approach based on Kleene algebra. In this approach, the primary objects of interest are not the abstract data values, but the transfer functions that manipulate them. These elements form a left-handed Kleene algebra. The dataflow labeling is not achieved by inductively labeling the program with abstract values, but rather by computing the star (Kleene closure) of a matrix of transfer functions. In this paper we show how this general framework applies to the problem of Java bytecode verification. We show how to specify transfer functions arising in Java bytecode verification in such a way that the Kleene algebra operations (join, composition, star) can be computed efficiently. We also give a hybrid dataflow analysis algorithm that computes the closure of a matrix on a cutset of the control flow graph, thereby avoiding the recalculation of dataflow information when there are cycles in the graph. This method could potentially improve the performance over the standard worklist algorithm when a small cutset can be found.     

基于免疫原理的可执行文件签名验证模型的研究

病毒发现和防治策略是操作系统安全框架的重要组成部分。目前通过特征码匹配进行查杀病毒的方法通常落后于计算机病毒的发展,已经不能满足日益迫切的安全需求。文章根据生物体免疫系统检测病毒的机理,提出了一种对可执行文件签名验证的模型,通过文件签名界定“自我”和“非我”,并以此为依据完成系统中恶意代码的发现。最后介绍了在Windows操作系统下开发的基于可执行文件签名验证模型的病毒检测系统。     

An overview of JML tools and applications

The Java Modeling Language (JML) can be used to specify the detailed design of Java classes and interfaces by adding annotations to Java source files. The aim of JML is to provide a specification language that is easy to use for Java programmers and that is supported by a wide range of tools for specification typechecking, runtime debugging, static analysis, and verification.This paper gives an overview of the main ideas behind JML, details about JML’s wide range of tools, and a glimpse into existing applications of JML.     

Stepwise Development of Process-Algebraic Specifications in Decorated Trace Semantics

Process algebras are convenient formalisms to develop specifications stepwise. This can be done with the help of partially defined states in a specification. When refining the specification, new transitions are added to partially defined states. At every step, it is verified with the help of special preorders, refinement relations, that the step leads towards a desired goal. This approach has already been introduced in the case, where the verification is based on weak bisimulation equivalence. We show in this article that refinement relations can also be developed in decorated trace semantics. Moreover, the intuitive picture seems to be simpler in trace-based than in bisimulation-based semantics. The algorithms to compute the new refinement relations are exponential in the worst case, but behave quite well in practical cases.     

面向SOC系统设计的层次化CDFG的扩展

本文主要介绍了层次化CDFG中标准控制结构和并行结构的扩充及转换方法,从而为在高层次 SOC设计中真正使用HCDFG提供了基础。同时,文中还给出了HCDFG在系统验证中的作用,它为不同方法的混合验证提供了统一而有效的内部结构。     

SCV及其在SoC验证中的应用

片上系统(System on Chip,SoC)是集成电路设计发展的趋势,验证在整个SoC设计中工作量巨大且至关重要.应用验证领域的最新成果SCV(SystemCVerification),提出了通过设计用户定义的事务接口(Transactor),对RTL(RegisterTransferLevel)级设计进行事务级验证的策略,并对一个具体的FIFO事例进行了验证.     

指数分布可靠性验证试验系统的设计与实现

工程实际中,大量产品采用指数分布模型。指数分布可靠性验证中,需查阅大量表格,计算分析繁琐,急需实用的计算分析软件系统。按国家军用标准提出了指数分布可靠性验证试验系统的设计与实现方法,并研制了分析软件,帮助工程技术人员快速、准确地选择验证试验方案,从而有效地评定产品质量,并使其达到预定目标。     

存储系统功能验证方法浅析

IC日益增长的设计复杂性和在时间、代价方面的需求,使得验证工作很重要却又困难重重。传统的简单验证方法和手段已不能满足 要求,采用新的验证方法势在必行。以存储系统功能性的验证为例,介绍了目前流行的先进的验证方法.包括ABV(Assertion-based verification)和TBV(Transaction-based verification)。对ASIC芯片的一般功能验证流程也作了较为详尽的分析。     

基于概率统计的签名认证系统的研究与应用

针对签名在办公自动化系统中的广泛应用,该文首先对各种签名识别技术进行介绍、分析和比较,然后介绍了一个基于生物特征手写签名认证的系统原型,并着重提出了基于概率统计的手写签名识别方法。