Securing interaction between threads and the scheduler in the presence of synchronization

The problem of information flow in multithreaded programs remains an important open challenge. Existing approaches to specifying and enforcing information-flow security often suffer from over-restrictiveness, relying on nonstandard semantics, lack of compositionality, inability to handle dynamic threads, inability to handle synchronization, scheduler dependence, and efficiency overhead for the code that results from security-enforcing transformations. This paper suggests a remedy for some of these shortcomings by developing a novel treatment of the interaction between threads and the scheduler. As a result, we present a permissive noninterference-like security specification and a compositional security type system that provably enforces this specification. The type system guarantees security for a wide class of schedulers and provides a flexible and efficiency-friendly treatment of dynamic threads.     

一种基于污点数据传播和无干扰理论的软件行为可信性分析模型

以无干扰理论为基础,提出了一种基于污点数据流的软件行为可信分析模型。该模型通过跟踪程序外部输入的污点数据,提取可能引发系统不可信的关键系统调用,并建立污点传播调用序列。利用完整性条件下的污点信息流无干扰模型来判定构成污点传播的系统调用序列执行时是否可信,并给出了调用序列可信性判定定理。     

一种基于无干扰的软件动态行为可信性分析方法

软件动态行为度量是可信计算必须要解决的核心问题之一。解决这个问题有两个关键步骤:第一,对软件动态行为进行行为建模;第二,对建模后的软件动态行为进行行为可信性分析。针对第二步,即建模完成后的行为可信性分析问题进行了研究,提出一种基于无干扰的软件动态行为可信性分析方法,并从理论上给出了行为可信性判定定理。     

A formal approach to the integrated analysis of security and QoS

Concurrent and distributed systems are subject to several requirements of different nature. Among them security and quality of service (QoS) are two fundamental aspects, which can have a profound impact on the system performability. Unfortunately, the study of the tradeoff between security guarantees and performance needs is hard to accomplish, because the related analysis activities are usually carried out separately. In this paper, we present an integrated and tool-supported methodology encompassing both activities, which can provide insights about how to trade the QoS delivered by a system with its security guarantees. The methodology is illustrated by assessing the effectiveness and the efficiency of the securing strategy implemented in the NRL Pump, a trusted device proposed to secure the replication of information from a low-security level enclave to a high-security level enclave.     

考虑位置失效的移动系统安全模型

以带位置扩展的移动进程π演算模型为形式化工具,在考虑位置失效的基础上,将移动系统的安全性质转换为系统进程在给定计算环境中的位置互模拟关系,提出了考虑位置失效的一种新安全模型。针对实际安全需求,该模型可以方便地描述不同的非干扰安全性质;该模型提供了一个统一的安全分析架构,可广泛用于移动计算系统的安全性分析。     

浅谈现场总线及现场总线控制系统

现场总线技术是一种集计算机技术,通信技术、集成电路技术及智能传感技术于一身的新兴控制技术,现代工业控制思想的核心是：控制功能进一步分散化,以体现“控制分散,危险分散”的设计思想,因其可在测量数据的基础上完成对工业过程的控制,使控制的危险进一步分散,从而满足现代化生产对工业控制日益提高安全性的要求。     

一种先进板料折弯机液压系统分析及其压力控制特点研究

本文介绍一种先进、高效板料折弯机的基本组成 ,分析了液压系统的工作原理 ,阐述了该机采用压力控制的技术特点 ,指出合理且完善的压力控制手段对提高液压系统乃至整个机器设备的性能有着不容忽视的作用     

A comparison of semantic models for noninterference

The literature on definitions of security based on causality-like notions such as noninterference has used several distinct semantic models for systems. Early work was based on state machine and trace-set definitions; more recent work has dealt with definitions of security in two distinct process algebraic settings. Comparisons between the definitions has been carried out mainly within semantic frameworks. This paper studies the relationship between semantic frameworks, by defining mappings between a number of semantic models and studying the relationship between notions of noninterference under these mappings.     

Noninterference in a predicative polymorphic calculus for access control

Polymorphic programming languages have been adapted for constructing distributed access control systems, where a program represents a proof of eligibility according to a given policy. As a security requirement, it is typically stated that the programs of such languages should satisfy noninterference. However, this property has not been defined and proven semantically. In this paper, we first propose a semantics based on Henkin models for a predicative polymorphic access control language based on lambda-calculus. A formal semantic definition of noninterference is then proposed through logical relations. We prove a type soundness theorem which states that any well-typed program of our language meets the noninterference property defined in this paper. In this way, it is guaranteed that access requests from an entity do not interfere with those from unrelated or more trusted entities.     

一种信任链传递模型研究

通过度量应用程序及其动态库的完整性来保障应用的静态可信,并且分析有交互的应用之间的关系,建立了一种信任链传递模型来保障应用运行过程中的动态可信,从而构建可信的应用环境。并基于无千扰理论,将系统抽象为应用程序、动作和状态输出,形式化地定义了应用运行可信,给出应用运行可信的条件和性质,推出应用运行可信定理,并证明了基于该模型的应用环境可信判定定理。