Building access control policy model for privacy preserving and testing policy conflicting problems

This paper proposes a purpose-based access control model in distributed computing environment for privacy preserving policies and mechanisms, and describes algorithms for policy conflicting problems. The mechanism enforces access policy to data containing personally identifiable information. The key component is purpose involved access control models for expressing highly complex privacy-related policies with various features. A policy refers to an access right that a subject can have on an object, based on attribute predicates, obligation actions, and system conditions. Policy conflicting problems may arise when new access policies are generated that are possible to be conflicted to existing policies. As a result of the policy conflicts, private information cannot be well protected. The structure of purpose involved access control policy is studied, and efficient conflict-checking algorithms are developed and implemented. Finally a discussion of our work in comparison with other related work such as EPAL is presented.     

基于角色的访问控制扩展模型的设计

基于角色的访问控制(RBAC)被普遍认为是当前最具有发展潜力的访问控制策略,已经成为信息安全等领域研究的热点之一。本文对典型RBAC模型进行了扩展,增加了对用户组、访问客体以及访问模式等概念的抽象。在有多用户参与以及多客体的大型分布式信息管理系统中该模型具有更好的可用性以及与现实世界更接近。     

访问控制模型研究综述

访问控制是一种重要的信息安全技术。为了提高效益和增强竞争力,许多现代企业采用了此技术来保障其信息管理系统的安全。对传统的访问控制模型、基于角色的访问控制模型、基于任务和工作流的访问控制模型、基于任务和角色的访问控制模型等几种主流模型进行了比较详尽地论述和比较,并简介了有望成为下一代访问控制模型的UCON模型。     

Access control management for ubiquitous computing

The purpose of ubiquitous computing is anywhere and anytime access to information within computing infrastructures that is blended into a background and no longer be reminded. This ubiquitous computing poses new security challenges while the information can be accessed at anywhere and anytime because it may be applied by criminal users. Additionally, the information may contain private information that cannot be shared by all user communities. Several approaches are developed to protect information for pervasive environments against malicious users. However, ad hoc mechanisms or protocols are typically added in the approaches by compromising disorganized policies or additional components to protect from unauthorized access.In this paper, we present a usage control model to protect services and devices in ubiquitous computing environments, which allows the access restrictions directly on services and object documents. The model not only supports complex constraints for pervasive computing, such as services, devices and data types but also provides a mechanism to build rich reuse relationships between models and objects. Finally, comparisons with related works are analysed.     

Model-driven specification and enforcement of RBAC break-glass policies for process-aware information systems

ContextIn many organizational environments critical tasks exist which – in exceptional cases such as an emergency – must be performed by a subject although he/she is usually not authorized to perform these tasks. Break-glass policies have been introduced as a sophisticated exception handling mechanism to resolve such situations. They enable certain subjects to break or override the standard access control policies of an information system in a controlled manner.ObjectiveIn the context of business process modeling a number of approaches exist that allow for the formal specification and modeling of process-related access control concepts. However, corresponding support for break-glass policies is still missing. In this paper, we aim at specifying a break-glass extension for process-related role-based access control (RBAC) models.MethodWe use model-driven development (MDD) techniques to provide an integrated, tool-supported approach for the definition and enforcement of break-glass policies in process-aware information systems. In particular, we provide modeling support on the computation independent model (CIM) layer as well as on the platform independent model (PIM) and platform specific model (PSM) layers.ResultsOur approach is generic in the sense that it can be used to extend process-aware information systems or process modeling languages with support for process-related RBAC and corresponding break-glass policies. Based on the formal CIM layer metamodel, we present a UML extension on the PIM layer that allows for the integrated modeling of processes and process-related break-glass policies via extended UML Activity diagrams. We evaluated our approach in a case study on real-world processes. Moreover, we implemented our approach at the PSM layer as an extension to the BusinessActivity library and runtime engine.ConclusionOur integrated modeling approach for process-related break-glass policies allows for specifying break-glass rules in process-aware information systems.     

使用会话期上下文检查的RBAC模型：RBAC CCS

在大型信息系统的设计中,访问控制一直是一项复杂的工作。基于角色的访问控制（RBAC）被推荐来代替传统的访问控制模型。应用到信息系统中时,需要解决RBAC的控制粒度问题。我们需要一个能够基于上下文进行细粒度访问控制的RBAC模型,即基于对象实例上下文上的访问控制。对现有的解决方案进行综述和比较,提出了使用会话期上下文检查的RBAC模型：RBACCCS。RBACCCS中用了参数化权限,在权限检查时用上下文变量实例化这些参数化权限,这样就解决了上下文的表示和上下文作用机制问题。最后对RBACCCS模型进行     

基于上下文的普适计算使用控制模型

目前普适计算中的访问控制绝大多数采用基于角色访问控制模型(RBAC);然而使用控制(UCON)模型具有可变性和持续性,更适合普适计算,但没有充分考虑上下文信息。在UCON模型中增加对上下文信息考虑的同时将义务和条件决策因素分为静态和动态,提出了基于上下文的普适计算使用控制(Con_UCON)模型,动态义务和条件作为使用过程中的决策因素;同时建立了模型的核心规则集,并给出了形式语言描述。该模型能满足普适计算环境中访问控制的需求。通过普适计算智能办公系统中的三个实例,证明此模型具有有效性、灵活性和安全性。     

PBAC: Provision-based access control model

Over the years a wide variety of access control models and policies have been proposed, and almost all the models have assumed “grant the access request or deny it.” They do not provide any mechanism that enables us to bind authorization rules with required operations such as logging and encryption. We propose the notion of a “provisional action” that tells the user that his request will be authorized provided he (and/or the system) takes certain actions. The major advantage of our approach is that arbitrary actions such as cryptographic operations can all coexist in the access control policy rules. We define a fundamental authorization mechanism and then formalize a provision-based access control model. We also present algorithms and describe their algorithmic complexity. Finally, we illustrate how provisional access control policy rules can be specified effectively in practical usage scenarios. Published online: 22 January 2002     

Access control and view generation for provenance graphs

Data provenance refers to the knowledge about data sources and operations carried out to obtain some piece of data. A provenance-enabled system maintains record of the interoperation of processes across different modules, stages and authorities to capture the full lineage of the resulting data, and typically allows data-focused audits using semantic technologies, such as ontologies, that capture domain knowledge. However, regulating access to captured provenance data is a non-trivial problem, since execution records form complex, overlapping graphs with individual nodes possibly being subject to different access policies. Applying traditional access control to provenance queries can either hide from the user the entire graph with nodes that had access to them denied, reveal too much information, or return a semantically invalid graph. An alternative approach is to answer queries with a new graph that abstracts over the missing nodes and fragments. In this paper, we present TACLP, an access control language for provenance data that supports this approach, together with an algorithm that transforms graphs according to sets of access restrictions. The algorithm produces safe and valid provenance graphs that retain the maximum amount of information allowed by the security model. The approach is demonstrated on an example of restricting access to a clinical trial provenance trace.     

Personal information leakage detection method using the inference-based access control model on the Android platform

The web services used on desktop can be accessed through a smartphone due to the development of smart devices. As the usage of smartphones increases, the importance of personal information security inside the smartphone is emphasized. The openness features of Android platform make a lot easier to develop an application and also deploying malicious codes into application is an easy task for hackers. The security practices are also growing rapidly as the number of malicious code increases exponentially. According to these circumstances, new methods for detecting and protecting the behavior of leaked personal information are needed to manage the personal information within a smartphone.In this paper, we study the permission access category in order to detect the malicious code, which discloses the personal information on Android environment such as equipment and location information, address book and messages, and solve the problem related to Resource access of Random Access Control method in conventional Android file system to detect the new malware or malicious code via the context ontology reasoning of permission access and API resource information which the personal information are leaked through. Then we propose an inference-based access control model, which can be enabled to access the proactive security. There is more improvement accuracy than existing malicious detecting techniques and effectiveness of access control model is verified through the proposal of inference-based access control model.     

An extended attribute based access control model with trust and privacy: Application to a collaborative crisis management system

Many efforts in the area of computer security have been drawn to attribute-based access control (ABAC). Compared to other adopted models, ABAC provides more granularity, scalability, and flexibility. This makes it a valuable access control system candidate for securing platforms and environments used for coordination and cooperation among organizations and communities, especially over open networks such as the Internet. On the other hand, the basic ABAC model lacks provisions for context, trust and privacy issues, all of which are becoming increasingly critical, particularly in high performance distributed collaboration environments. This paper presents an extended access control model based on attributes associated with objects and subjects. It incorporates trust and privacy issues in order to make access control decisions sensitive to the cross-organizational collaboration context. Several aspects of the proposed model are implemented and illustrated by a case study that shows realistic ABAC policies in the domain of distributed multiple organizations crisis management systems. Furthermore, the paper shows a collaborative graphical tool that enables the actors in the emergency management system to make better decisions. The prototype shows how it guarantees the privacy of object’s attributes, taking into account the trust of the subjects. This tool incorporates a decision engine that relies on attribute based policies and dynamic trust and privacy evaluation. The resulting platform demonstrates the integration of the ABAC model, the evolving context, and the attributes of actors and resources.     

应用于多级安全网络的安全策略模型研究

为了应用多级安全策略,阻止信息流向不受信任的目的地,将BLP模型完整性增强的安全策略扩展到多级安全网络中,基于信息流的强制访问控制机制提出一个应用于多级安全网络的安全策略模型.该模型主要为网络层和数据链路层数据流提供相应的安全策略,很好地保证网络中数据流的机密性和完整性.     

Linux通用访问控制框架的设计

访问控制是用来处理主体和客体之间交互的限制,是安全操作系统最重要的功能之一。Linux系统中所采用的访问控制是传统UNIX的基于访问模式位的单一的自主访问控制,在实现这一功能时,系统的访问控制代码散列在核心中,没有形成统一的访问控制模块和相应的接口,不支持策略与机制的分离,缺乏相应的灵活性、扩充性以及易维护性,无法定制化系统的访问控制策略。而在当前以分布式计算作为主导计算模式的背景之下,Linux系统中原有的访问控制是无法满足信息处理系统的日益多样化安全需求。针对上述Linux系统中访问控制机制的缺陷,该文引入了一种通用的访问控制框架称之为Linux通用访问控制框架。该框架是一种与具体的访问控制策略无关的体系结构,支持系统的访问控制策略和机制的分离,与传统的Linux访问控制相比,它借助于在Linux核心系统中得到广泛应用的框架式抽象数据类型,提供了一个一致的、抽象的访问控制接口从而对多种访问控制策略如强制访问控制、基于角色的访问控制等加以支持。在该框架之下,用户甚至可以提供自己的访问控制策略模块,以获得具有更高的灵活性、扩充性和易维护性的系统访问控制机制。同时,由于该框架的引入,系统的访问控制策略模块可以与系统其它部分相分离,从而有利于系统访问控制的结构化?     

Flexible secure inter-domain interoperability through attribute conversion

The access control policy of an application that is composed of interoperating components/services is defined in terms of the access control policies enforced by the respective services. These individual access control policies are heterogenous in the sense that the services may be independently developed and managed and it is not practical to assume that all policies are defined with respect to some uniform domain vocabulary of policy attributes. A framework is described that provides a domain mapping for heterogenous policies. A fuzzy-based conversion mechanism determines the degree to which an access control attribute of one (service) policy may safely interoperate with an access control attribute of another (service) policy. The approach is scalable in the sense that it is not necessary to a priori specify every pairwise policy interoperation relationship, rather, where obvious interpretations exist then policy relationships are specified, while other relationships are inferred using the fuzzy mechanism.     

可扩展存取控制建模、实现与应用

有效控制资源的存取是实现多用户协同工作的关键,也是信息安全的重要保障。在分析传统存取控制技术的基础上,提出了一种新型的存取控制模型——可扩展存取控制模型（XACM）。基于该模型设计的可扩展存取控制系统成功应用于某公司基于工作流技术的办公自动化系统中信息的存取控制,表现出优良的通用性和灵活性。     

RBAC及XACML在制造网格访问控制中的应用

研究符合制造网格特点的访问控制规范,引入“角色”及“授权服务”设定用户的访问策略,在用户访问具体资源时再根据资源拥有者设置特定的权限来确定用户的访问权限,以实现制造网格总体访问策略和用户自主访问策略的协同,为制造网格平台提供符合制造业特点的安全功能和服务。     

基于使用控制和上下文的动态网格访问控制模型研究

网格环境动态、多域和异构性的特点决定其需要灵活、易于扩展和精细的授权机制.近来在网格环境下的访问控制方面做了大量研究,现有的模型大多在相对静止的前提下,基于主体的标识、组和角色信息进行授权,缺乏具体的上下文信息和灵活的安全策略.本文提出了网络环境下基于使用控制和上下文的动态访问控制模型.在该模型中,授权组件使用主体和客体属性定义传统的静态授权;条件组件使用有关的动态上下文信息体现了对主体在具体环境中的动态权限控制.在该模型的基础上,本文实现了一个原型系统,以验证模型的效率和易于实现性.     

一种新型访问控制技术研究

使用控制（UCON）是对访问控制的一种概述,它包含授权、职责、条件、连续性（正在进行的控制）和易变性。通常来说,访问控制只是对主体访问的目标资源进行授权,作为访问的结果并没有进行系统的分析研究。文章根据使用控制的需求,研究了一种ABC模型,该模型定义为使用控制的核心模型,并且说明了它是怎样包含了传统的访问控制。例如强制的、自主的、基于角色的访问控制。另外,也讨论了它的体系结构。引入了一种全新的对使用控制及其变化的监控方法。     

CDS访问控制模型研究与实现

通过分析协同设计系统对访问控制的特殊需求,研究现有访问控制模型的特点,设计了一个面向协同设计系统的访问控制模型-（CDAC Model）。该模型不但支持用户身份动态改变,体现时序依赖概念,而且能够控制委托深度,遵循最小特权和职责分离原则,同时还减少了因个人权限受到攻击对信息系统造成危害的概率,很好地满足了协同设计系统对访问控制的要求。     

Specification and enforcement of flexible security policy for active cooperation

Interoperation and services sharing among different systems are becoming new paradigms for enterprise collaboration. To keep ahead in strong competition environments, an enterprise should provide flexible and comprehensive services to partners and support active collaborations with partners and customers. Achieving such goals requires enterprises to specify and enforce flexible security policies for their information systems. Although the area of access control has been widely investigated, current approaches still do not support flexible security policies able to account for different weighs that typically characterize the various attributes of the requesting parties and transactions and reflect the access control criteria that are relevant for the enterprise. In this paper we propose a novel approach that addresses such flexibility requirements while at the same time reducing the complexity of security management. To support flexible policy specification, we define the notion of restraint rules for authorization management processes and introduce the concept of impact weight for the conditions in these restraint rules. We also introduce a new data structure for the encoding of the condition tree as well as the corresponding algorithm for efficiently evaluating conditions. Furthermore, we present a system architecture that implements above approach and supports interoperation among heterogeneous platforms.