"长城"安全政策的扩充研究及其实现

"长城"安全政策(Chinese Wall Security Policy,CWSP)是商业信息领域中重要的安全政策之一.但是Brewer-Nash提出的CWSP并不能很好地满足实际的需要.基于角色的访问控制(Role-Based Access Control,RBAC)模型是一种"政策中性(Policy Neutral)"的模型,被看作是最有可能替代传统的自主和强制访问控制模型的一种全新的模型,正越来越被信息安全领域所重视.本文首先介绍了RBAC和"长城"安全政策,然后根据实际应用对CWSP作了系统的扩充,最后本文系统地论述了基于RBAC的扩充CWSP的实现方法.     

一种基于策略的跨自主域访问控制模型研究

针对分布式环境下各自主域访问控制模型的异构性以及跨域访问中域自治与协作问题,提出了一种基于策略的跨自主域访问控制模型.该模型通过自主域间访问主体的不同粒度映射机制,支持域间的安全互操作;通过安全控制器并结合基于XACML的访问控制策略,实现了域间用户权限的逻辑整合.各域的相关权限信息封装在域内,既保持原有的独立性又实现了域间的协作,同时屏蔽了域间主体差异,解决了不同域系统互不认知和异构访问控制模型映射问题.     

ASPE: attribute-based secure policy enforcement in vehicular ad hoc networks

Vehicular ad hoc networks (VANETs) are usually operated among vehicles moving at high speeds, and thus their communication relations can be changed frequently. In such a highly dynamic environment, establishing trust among vehicles is difficult. To solve this problem, we propose a flexible, secure and decentralized attribute based secure key management framework for VANETs. Our solution is based on attribute based encryption (ABE) to construct an attribute based security policy enforcement (ASPE) framework. ASPE considers various road situations as attributes. These attributes are used as encryption keys to secure the transmitted data. ASPE is flexible in that it can dynamically change encryption keys depending on the VANET situations. At the same time, ASPE naturally incorporates data access control policies on the transmitted data. ASPE provides an integrated solution to involve data access control, key management, security policy enforcement, and secure group formation in highly dynamic vehicular communication environments. Our performance evaluations show that ASPE is efficient and it can handle large amount of data encryption/decryption flows in VANETs.     

手机支付安全研究

针对手机支付安全问题,通过介绍手机的现场支付和远场支付业务,分析了手机终端、无线网络、支付平台所面临的安全威胁,提出了解决手机支付安全问题的安全框架。该安全框架通过综合应用密码技术、访问控制、安全协议、安全审计等4种安全技术手段和手机终端安全管理策略、通信传输安全管理策略、支付平台安全管理策略等3种安全管理策略为保障手机支付的安全提供了一种解决方案。     

基于加权熵的访问控制策略安全性分析研究

为解决访问控制策略的安全性分析问题,提出了一种基于信息熵的策略量化分析理论.首先,根据信息论中加权熵的知识定义了策略安全熵,提出了非授权访问行为的最大不确定性计算方法.然后,分别给出了典型访问控制策略的一维安全熵和N维安全熵,并对结果进行了证明.最后,依据安全熵分析了典型访问控制策略的安全性.     

Homonymous role in role‐based discretionary access control

The access control model is a core aspect of trusted information systems. Based on the role based access control (RBAC) model, we put forward the concept of the homonymous role, which extends the role control categories in RBAC, balances the control granularity and the storage space requirements, and executes the fine‐grained access control. Instead of the traditional global access control policies (GACP), we propose the homonymous control domain (HCD) mechanism to enable the coexistence of multiple types of access control policies in a single system, thereby improving the control granularity and flexibility. The HCD mechanism facilitates the discretionary supporting of independent access control policies for its homonymous user. The HCD mechanism and the traditional access control mechanism can be linked to construct a two‐layer access control policy mechanism for a system. Notably, we also consider the temporal characteristic in HCD, which is a critical feature of modern access control models. Furthermore, we analyze the conflicts between the HCD and GACP mechanisms. Finally, we design and implement our HCD on FreeBSD to demonstrate the advantages of the two‐layer access control mechanism. Copyright © 2008 John Wiley & Sons, Ltd.     

Cross-domain access control policy mapping mechanism for balancing interoperability and autonomy

Cross-domain access control can improves interoperability but reduces intra-domain autonomy.To balance inter-domain interoperability and intra-domain autonomy,a cross-domain access control policy mapping to the problem of multi-objective integer optimization programming was formulated.Both the maximization of inter-domain interoperability and the minimization of intra-domain autonomy were taken as the objectives.Further,seven constraints were designed to prevent typical cross-domain conflicts.To solve the optimization problem,a constrained NSGA-III algorithm was proposed.The experimental results show that the proposed algorithm can quickly converge and accurately find the policy mapping even in the large-scale datasets.     

一种支持动态调节的最小特权安全策略架构

最小特权机制可为安全操作系统提供恰当的安全保证级.本文描述了一种支持动态调节的最小特权安全策略架构,它结合角色的职责隔离和域的功能隔离特性,通过一种基于进程上下文—角色、执行域和运行映像的权能控制机制,将每个进程始终约束在这些上下文允许的最小特权范围内.本文实例分析了该架构在安胜OS v4.0,一种自主开发的、符合GB17859-1999第四级——结构化保护级的安全操作系统中的实现.结果表明,它可支持安全操作系统实施动态调节的最小特权控制,并提供灵活有效的系统.     

A new framework for GLIF Interdomain Resource Reservation Architecture (GIRRA)

Many existing and emerging Scientific high-end applications (E-science) require end-to-end circuits interconnecting Grid resources for large data transfers. A few advanced networks, mainly National Research and Education Networks (NRENs), such as Surfnet, National Lambda Rail and Internet 2, now provide mechanisms for end-users to reserve and provision lightpaths via middleware referred to as Network Resource Mangers (NRMs). Although, some progress has been made in automated intra-domain lightpath services, inter-domain lightpath provisioning still requires manual intervention and presents several key challenges such as scalability of topology information exchanged, consistency and scalability of information model, security of access to the resources, hybrid networking and multi-layer lightpaths, and accounting and billing. In this paper, we describe a new architectural framework called Global Lambda Integrated Facility (GLIF) Interdomain Resource Reservation Architecture (GIRRA) with the goal to provide an integrated response to these challenges. We propose a new approach to model GLIF network domains and GOLEs as virtual switches and to describe their behavior, functionality, policy capabilities, and topology aggregation. We define an inter-domain path computation model to determine paths that meet constraints and access policy restrictions. We propose a security framework for authentication and authorization of users and a model for accounting and billing that aims to provide easy and secure access to the resources. Key aspects of the GIRRA solution are that it focuses on the inter-dependence between different challenges of inter-domain path provision, and it is built around already existing solutions for intra-domain resource provisioning.     

基于角色的域-类型增强访问控制模型研究及其实现

安全系统只有能够支持多种安全政策才能满足实际需求.基于角色的访问控制(Role-Based Access Control,RBAC)是一种政策中性(Policy Neutral)的新模型,已经实现了多种安全政策.域-类型增强(Domain and Type Enforcement,DTE)安全政策充分体现了最小特权(Least Privilege)和职责分离(Separation of Duty)的安全原则,但是,RBAC96不便于直接实现DTE.根据RBAC和DTE的思想,本文提出了"基于角色的域-类型增强访问控制"(Role-Based Domain and Type Enforcement Access Control,RDTEAC)模型.该模型继承了RBAC96的优点,又体现了DTE的安全思想,并易于实现DTE安全政策.此外,我们还在Linux上实现了RDTEAC模型的一个原型.