Role-based Delegation Research Articles

Modeling Support for Role-Based Delegation in Process-Aware Information Systems

In the paper, an integrated approach for the modeling and enforcement of delegation policies in process-aware information systems is presented. In particular, a delegation extension for process-related role-based access control (RBAC) models is specified. The extension 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 delegation models. Moreover, the detection of delegation-related conflicts is discussed and a set of pre-defined resolution strategies for each potential conflict is provided. Thereby, the design-time and runtime consistency of corresponding RBAC delegation models can be ensured. Based on a formal metamodel, UML2 modeling support for the delegation of roles, tasks, and duties is provided. A corresponding case study evaluates the practical applicability of the approach with real-world business processes. Moreover, the approach is implemented as an extension to the BusinessActivity library and runtime engine.

Comprehensive two-level analysis of role-based delegation and revocation policies with UML and OCL

ContextRole-based access control (RBAC) has become the de facto standard for access management in various large-scale organizations. Often role-based policies must implement organizational rules to satisfy compliance or authorization requirements, e.g., the principle of separation of duty (SoD). To provide business continuity, organizations should also support the delegation of access rights and roles, respectively. This, however, makes access control more complex and error-prone, in particular, when delegation concepts interplay with SoD rules. ObjectiveA systematic way to specify and validate access control policies consisting of organizational rules such as SoD as well as delegation and revocation rules shall be developed. A domain-specific language for RBAC as well as delegation concepts shall be made available. MethodIn this paper, we present an approach to the precise specification and validation of role-based policies based on UML and OCL. We significantly extend our earlier work, which proposed a UML-based domain-specific language for RBAC, by supporting delegation and revocation concepts. ResultWe show the appropriateness of our approach by applying it to a banking application. In particular, we give three scenarios for validating the interplay between SoD rules and delegation/revocation. ConclusionTo the best of our knowledge, this is the first attempt to formalize advanced RBAC concepts, such as history-based SoD as well as various delegation and revocation schemes, with UML and OCL. With the rich tool support of UML, we believe our work can be employed to validate and implement real-world role-based policies.

Independently Verifiable Decentralized Role-Based Delegation

In open systems such as cloud computing platforms, delegation transfers privileges among users across different administrative domains and facilitates information sharing. We present an independently verifiable delegation mechanism, where a delegation credential can be verified without the participation of domain administrators. Our protocol, called role-based cascaded delegation (RBCD), supports simple and efficient cross-domain delegation of authority. RBCD enables a role member to create delegations based on the dynamic needs of collaboration; in the meantime, a delegation chain can be verified by anyone without the participation of role administrators. We also describe an efficient realization of RBCD by using aggregate signatures, where the authentication information for an arbitrarily long role-based delegation chain is captured by one short signature of constant size.

Hierarchical Role-Based Delegation Authorization Execution Model for Service Grid

针对网格应用中对委托限制的多方面需求,提出了基于层次角色委托的服务网格授权执行模型.模型支持委托角色授予与撤销功能以及相应的关联性限制特性.通过加入信任度,细化了关联性限制的表达粒度.通过定义角色树作为委托授权的基本单位并对角色树进行剪枝,改善了部分委托实现的难度.通过定义带信任度的委托传播树,细化了对委托传播限制的控制.提出的委托凭证全面支持了角色委托的临时性、关联性、部分性、传播性限制需求.对模型中的委托授权执行规则作了形式化描述,并证明了执行规则能够细粒度地控制委托授权的执行过程.实例展示表明,模型能够满足网格应用对委托限制多方面的需求.

Delegating revocations and authorizations in collaborative business environments

Efficient collaboration allows organizations and individuals to improve the efficiency and quality of their business activities. Delegations, as a signif icant approach, may occur as workflow collabora tions, supply chain collaborations, or collaborative commerce. Role-based delegation models have been used as flexible and efficient access management for collaborative business environments. Delegation revocations can provide significant functionalities for the models in business environments when the delegated roles or permissions are required to get back. However, problems may arise in the revocation process when one user delegates user U a role and another user delegates U a negative authorization of the role. This paper aims to analyse various role-based delegation revocation features through examples. Revocations are categorized in four dimensions: Dependency, Resilience, Propagation and Dominance. According to these dimensions, sixteen types of revocations exist for specific requests in collaborative business environments: DependentWeakLocalDelete, Dependent WeakLocalNegative, DependentWeakGlobalDelete, DependentWeakGlobalNegative, IndependentWeak LocalDelete, IndependentWeakLocalNegative, Inde pendentWeakGlobalDelete, IndependentWeakGlobal Negative, and so on. We present revocation delegating models, and then discuss user delegation authorization and the impact of revocation operations. Finally, comparisons with other related work are discussed.

Towards secure information sharing using role-based delegation

As computing becomes more pervasive, information sharing occurs in broad, highly dynamic network-based environments. Such pervasive computing environments pose a difficult challenge in formally accessing the resources. The digital information generally represents sensitive and confidential information that organizations must protect and allow only authorized personnel to access and manipulate them. As organizations implement information strategies that call for sharing access to resources in the networked environment, mechanisms must be provided to protect the resources from adversaries. In this paper, we seek to address the issue of how to advocate selective information sharing while minimizing the risks of unauthorized access. We integrate a role-based delegation framework to propose a system architecture. We also demonstrate the feasibility of our framework through a proof-of-concept implementation.

A Constrained Role-Based Delegation Model

Delegation is an important security policy that should be supported by RBAC model. The basic idea of delegation is that some active entity in a system delegates authority to another active entity to carry out some functions on behalf of the former. The grantor of the delegated roles should be responsible for the usage of them, so constraints on the usage of the delegated roles are critical components of the whole delegation model. Currently, there’re some models that extend RBAC model to support role delegation. However, their supports for constraints on the usage of delegated roles are very limited. This paper presents the requirements of role-based delegation, including temporary constraints, regular role dependency constraints, partial delegation constraints and propagation constraints. The former two kinds of constraints are modeled with a formal model – CRDM, which provides the foundation for applications in need of the constrained delegation.

A rule-based framework for role-based delegation and revocation

Delegation is the process whereby an active entity in a distributed environment authorizes another entity to access resources. In today's distributed systems, a user often needs to act on another user's behalf with some subset of his/her rights. Most systems have attempted to resolve such delegation requirements with ad-hoc mechanisms by compromising existing disorganized policies or simply attaching additional components to their applications. Still, there is a strong need in the large, distributed systems for a mechanism that provides effective privilege delegation and revocation management. This paper describes a rule-based framework for role-based delegation and revocation. The basic idea behind a role-based delegation is that users themselves may delegate role authorities to others to carry out some functions authorized to the former. We present a role-based delegation model called RDM2000 (role-based delegation model 2000) supporting hierarchical roles and multistep delegation. Different approaches for delegation and revocation are explored. A rule-based language for specifying and enforcing policies on RDM2000 is proposed. We describe a proof-of-concept prototype implementation of RDM2000 to demonstrate the feasibility of the proposed framework and provide secure protocols for managing delegations. The prototype is a web-based application for law enforcement agencies allowing reliable delegation and revocation. The future directions are also discussed.