Coordinating access control in grid services

As the need for more pervasive and more complex access controls grows, the challenge of ensuring the performance of access control systems is becoming apparent. Researchers have proposed several solutions to mitigate performance problems, including: adjusting the policy set; re-engineering the policy decision point (PDP); and decomposing the policies and distributing their evaluation. However, since the benefits and tradeoffs depend heavily upon the actual scenario, security administrators typically do not have objective justification for adopting particular mitigation actions. In response, we present the ATLAS framework, comprising: 1) DomainManager , which facilitates modelling the domain as closely as possible and automatically generates large numbers of representative policies and associated requests; 2) STACS , which enables controlled experiments to be performed using the generated policies/requests, to collect comprehensive measurements of PDP performance; and 3) PARPACS , which aids the understanding and worth of the measurement data and, by using rigorous validation techniques, reduces the risk of spurious insights or incorrect recommendations. We present a discussion of ATLAS as applied to an enterprise communication scenario, where access control is realised via XACML PDPs. Notable insights include that the SunXacml 2.0 PDP performs relatively poorly in terms of policy evaluation performance and that adding additional memory and/or processor cores to a XACML PDP server is not guaranteed to improve performance significantly.

Large-scale scientific and engineering applications are increasingly being hosted as Grid services using Globus middleware complying to the Open Grid Services Architecture (OGSA) framework. In order for users to fully embrace Grid applications, seamless access to Grid services is required. In working towards this aim we present the design and implementation of Grid clients that utilise the language-independent Microsoft .NET Framework that can be deployed without software prerequisites (zero-deployment). We demonstrate runtime security authentication interoperability between Microsoft Windows-native SSPI and the Globus GSSAPI, with full proxy support. This is demonstrated with a .NET GridFTP client, called MyGridFTP. We believe that this is one of the first implementations to use Windows native security infrastructure to interoperate with the Grid Security Infrastructure in Globus. This paves the way for language-independent .NET clients to be written that are fully interoperable with Globus-based Grid services. This work is part of a larger experimental aerodynamics Wind Tunnel Grid project, which has significant requirements for data management from acquisition, collating, processing, analysis and visualisation.

In conventional centralized authorization models, the evaluation performance of policy decision point (PDP) decreases obviously with the growing numbers of rules embodied in a policy. Aiming to improve the evaluation performance of PDP, a distributed policy evaluation engine called XDPEE is presented. In this engine, the unicity of PDP in the centralized authorization model is changed by increasing the number of PDPs. A policy should be decomposed into multiple subpolicies each with fewer rules by using a decomposition method, which can have the advantage of balancing the cost of subpolicies deployed to each PDP. Policy decomposition is the key problem of the evaluation performance improvement of PDPs. A greedy algorithm with O(nlgn) time complexity for policy decomposition is constructed. In experiments, the policy of the LMS, VMS, and ASMS in real applications is decomposed separately into multiple subpolicies based on the greedy algorithm. Policy decomposition guarantees that the cost of subpolicies deployed to each PDP is equal or approximately equal. Experimental results show that (1) the method of policy decomposition improves the evaluation performance of PDPs effectively and that (2) the evaluation time of PDPs reduces with the growing numbers of PDPs.

Traditional access control systems often use the extensible access control markup language (XACML), a widely adopted standard for defining and enforcing access control policies. XACML is flexible and compatible with various access control models. It comprises key components such as the Policy Decision Point (PDP), Policy Enforcement Point (PEP), Policy Administration Point (PAP), and Policy Information Point (PIP), which are centrally managed in traditional setups. However, this central management introduces vulnerabilities like Single Point of Failure (SPOF) and other security risks. This research addresses these challenges by proposing a decentralized access control architecture built on Hyperledger Fabric. The design distributes the four core components of XACML— PEP, PDP, PAP, and PIP- across multiple blockchain nodes, eliminating SPOF while enhancing scalability and data integrity. A proof of concept (PoC) implementation is developed to evaluate the system’s performance. The architecture and PoC are analyzed against predefined threats and requirements, demonstrating how the system delivers a secure, scalable, and resilient access control solution.

Access control is the process of mediating every request to resources and data maintained by a system and determining whether the request should be granted or denied. The access control decision is enforced by a mechanism implementing regulations established by a security policy. Different access control policies can be applied, corresponding to different criteria for defining what should, and what should not, be allowed, and, in some sense, to different definitions of what ensuring security means. In this chapter we investigate the basic concepts behind access control design and enforcement, and point out different security requirements that may need to be taken into consideration. We discuss several access control policies, and models formalizing them, that have been proposed in the literature or that are currently under investigation.

Access control is the process of mediating every request to resources and data maintained by a system and determining whether the request should be granted or denied. The access control decision is enforced by a mechanism implementing regulations established by a security policy. Different access control policies can be applied, corresponding to different criteria for defining what should, and what should not, be allowed, and, in some sense, to different definitions of what ensuring security means. In this chapter we investigate the basic concepts behind access control design and enforcement, and point out different security requirements that may need to be taken into consideration. We discuss several access control policies, and models formalizing them, that have been proposed in the literature or that are currently under investigation.

In ubiquitous computing environments access control decisions have to be adaptable to changes of the situation or state of an entity, in order to properly adjust to these changes without the need of manual interaction. A solution to this challenge is context-aware access control, where the mentioned changes are influencing access control decisions. In this paper we present a security framework for mobile business applications that is capable of performing context-aware access control on message level. There are several components in the framework that together (1) ensure that security requirements defined in policies are enforced in the framework, (2) provide context information and apply plausibility checks to increase the confidence that context information represents the actual situation or state (context) of an entity, and (3) perform the access-control decisions based on a combination of classic access control schemes and context information. In addition, a scenario is described where the introduced features of the framework are applied

A Virtual Organization (VO) consists of some real organizations with common interests, which aims to provide inter organizational associations to reach some common goals by sharing their resources with each other. Providing security mechanisms, and especially a suitable access control mechanism, which enforces the defined security policy is a necessary requirement in VOs. Since VO is a complex environment with the huge number of users and resources, traditional access control models cannot satisfy VOs security requirements. Most of the current proposals are basically based on the attributes of users and resources. In this paper, we suggest using a combination of the semantic based access control (SBAC) model, and the attribute based access control (ABAC) model with the shared ontology of subjects' attributes in VOs. In this model, each participating organization makes its access control decisions according to an enhanced model of the ABAC model. However, access decision in the VO is made in more abstract level through an enhanced model of theSBACmodel. Using the ontology of users and resources in this model facilitates access control in large scale VOs with numerous organizations. By the combination ofSBACand ABAC, we attain their benefits and eliminate their shortcomings. In order to show the applicability of the proposed model, an access control system, based on the proposed model, has been implemented in Java using available APIs, including Sun's XACML API, Jena, Pellet, and Protege.

Access control in dynamic environments needs the ability to provide more access opportunities of information to users, while also ensuring protection information from malicious users. Trust and risk are essential factors and can be combined together in access control decision-making to meet the above requirement. In this paper, we propose the combination of the trust and risk in access control to balance information accessibility and protection. Access control decision is made on the basis of trustworthiness of users and risk value of permissions. We use potential relations between users and relations between permissions in access control. Our approach not only provides more access opportunities for trustworthy users in accessing permissions, but also enforces traditional access control constraints such as Chinese Wall policy and Separation of Duty (SoD) of Role-Based Access Control (RBAC) model in an effective way.

Healthcare systems are increasingly vulnerable to security threats due to their reliance on digital platforms. Traditional access control models like Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC) have limitations in mitigating evolving risks in these systems. Despite their unique features, these models face limitations in mitigating evolving risks in healthcare systems. Traditional models are primarily oriented towards allocating permissions according to predetermined roles or policies, which results in challenges in effectively adapting to the dynamic complexities of modern healthcare ecosystems. Therefore, this paper proposes a novel risk-aware RBAC and ABAC access control model to enhance the flexibility, adaptability and security issues associated with healthcare systems. The proposed model integrates RBAC for role-based categorization, ABAC for fine-grained control based on user attributes and environmental factors, and Risk-Based Access Control (RiBAC) for dynamic risk assessment. The proposed model dynamically adjusts access permissions based on risk values, ensuring accurate and adaptable access control decisions. The experimental results demonstrate the feasibility and effectiveness of the proposed model in granting access to authorized users while denying access to unauthorized users. Through a series of 43 experiments that simulate various scenarios of access control operations in the healthcare system, the proposed model demonstrates significant improvement in the accuracy, precision, and recall of access control decisions compared to traditional models. The proposed model’s ability to dynamically assess risk and adjust access permissions based on contextual factors significantly enhances its ability to mitigate threats and protect sensitive medical data.

An efficient policy evaluation engine for XACML policy management

In many jurisdictions, patients are being increasingly empowered to play a critical role in defining how their medical information can be collected, used and shared across various healthcare data custodians. This patient-centric focus on information custody and management, along with the highly distributed nature of medical information, introduces new access control challenges related to privacy and security of medical information. As a result, when exchanging medical information across systems under different administrative domains, traditional access control models are not effective to enforce patient privacy preferences. To address this challenge, we propose an access control scheme that is patient-centric and offers a consent-based access control solution usable across heterogeneous medical information systems. Our model utilizes a logic-based approach to make inferences about access control decisions, and uses ontology-based knowledge representation to ensure that privacy preferences are correctly understood and applied. All system-level access control decisions can be automated and independently verified for validity and correctness. Our proposed solution offers a flexible and robust model that is most suited for the demanding access control scenarios present in patient care.

In modern pervasive applications, it is important to validate access control mechanisms that are usually defined by means of the standard XACML language. Mutation analysis has been applied on access control policies for measuring the adequacy of a test suite. In this paper, we present a testing framework aimed at applying mutation analysis at the level of the Java based policy evaluation engine. A set of Java based mutation operators is selected and applied to the code of the Policy Decision Point (PDP). A first experiment shows the effectiveness of the proposed framework in assessing the fault detection of XACML test suites and confirms the efficacy of the application of code-based mutation operators to the PDP.

The communication process of devices in IoV under cloud architecture needs to be protected by access control models. However, existing access control models have difficulty establishing the appropriate granularity of permissions in the face of large amounts of data in IoV. Moreover, the access control model may need to temporarily change user privileges to accommodate the dynamic nature of IoV scenarios, a requirement that is difficult to implement for traditional access control models. The unstable connection status of devices in IoV also creates problems for access control. The service (composed of role and attribute) based access control model (in IoV) S-RABAC (V), under the Cloud computing architecture, introduces a formal theoretical model. The model uses attribute grouping and prioritization mechanisms to form a hierarchical structure. The permission combination pattern in the hierarchical structure can avoid duplicate permissions and reduce the number of permissions while ensuring fine-grained permissions. Different layers in the model have different priorities, and when a user’s permission requires temporary changes, it can be adjusted to the corresponding layers according to the user’s priority. In addition, users are allowed to keep their assigned privileges for a period to avoid frequent access control because of unstable connections. We have implemented the proposed access control model in Alibaba Cloud Computing and given six example demonstrations. The experiment shows that this is an access control model that can protect IoV security more effectively. Various unique mechanisms in the model enable S-RABAC(V) to improve the overall access control efficiency. The model adds some extra features compared to ABAC and RBAC and can generate more access control decisions using the priority mechanism.

This paper first brief reviews the state of the security technology research and access control in the web service environment. Despite recent advances in access control approaches for Web Services, the heterogeneity of subjects and objects in Web Service environment has made it difficult to development of effective access control system. So we present a context-aware service-orient role-based access control model (CSRBAC). In CSRBAC model, access control system can make its access control decisions by capturing security relevant environmental context, such as time, location, operation state, or other environmental information. Based on CSRBAC model, a secure architecture model for Web Services is presented. It implements an access control system with dynamically grant and adapt permissions to users based on their current context. Compared to traditional access control mechanisms, the CSRBAC model can provide management flexibility and improved security for Web Services applications.KeywordsAccess ControlRole AssignmentContext ParameterPolicy Decision PointAccess Control SystemThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.