65,120 research outputs found
Providing Secure Coordinated Access to Grid Services
No full textCoordinating the cumulative use of distributed resources in a grid environment so that users do not consume too much is a difficult task. This paper presents one approach that we have implemented in Globus Toolkit version 4 (GT4), that uses an SQL database to hold coordination data, and policy decision points (PDPs) to make access control decisions about whether the users request for more resources can be granted or denied. When access is granted, obligations in the policy ensure that the coordination database is appropriately updated. In our initial implementation, the coordination service is embedded into the GT4 authorization chain as a custom PDP so that any web service can be provided with a security policy that provides a coordination capability. In the final section we describe how coordinated decision making could be more tightly integrated into a future version of GT
Coordinating access control in grid services
No full textWe describe how to control the cumulative use of distributed grid resources by using coordination-aware policy decision points (coordinated PDPs) and an SQL database to hold 'coordination' data. When access to a resource is granted, obligations in the security policy ensure that the coordination database is updated. The coordination database is a normal grid service providing distributed access to the coordinated PDPs. Access to the databases is secured by the grid security infrastructure (GSI) and its own PDP, so that only authorized users (the coordinated PDPs) can access it. A coordinated PDP is imbedded into the Globus Toolkitv4 authorization chain as a custom PDP so that any grid service can be protected by a security policy that provides a coordination capability. Each coordinated PDP uses the services of an uncoordinated PDP to make its access control decisions, so that any existing stateless PDP can be supplemented with a coordination capability. We provide performance results for the coordinated PDPs and compare these with two stateless PDPs. Virtually the entire performance penalty of using coordinated PDPs is accounted for by the heavy costs of using GSI to secure communications between the coordinated PDPs and the coordination database
PERMIS: a modular authorization infrastructure
No full textAuthorization infrastructures manage privileges and render access control decisions, allowing applications to adjust their behavior according to the privileges allocated to users. This paper describes the PERMIS role-based authorization infrastructure along with its conceptual authorization, access control, and trust models. PERMIS has the novel concept of a credential validation service, which verifies a user's credentials prior to access control decision-making and enables the distributed management of credentials. PERMIS also supports delegation of authority; thus, credentials can be delegated between users, further decentralizing credential management. Finally, PERMIS supports history-based decision-making, which can be used to enforce such aspects as separation of duties and cumulative use of resources. Details of the design and the implementation of PERMIS are presented along with details of its integration with Globus Toolkit, Shibboleth, and GridShib. A comparison of PERMIS with other authorization and access control implementations is given, along with suggestions where future research and development are still needed
A privacy preserving authorisation system for the cloud
No full textIn this paper we describe a policy based authorisation infrastructure that a cloud provider can run as an infrastructure service for its users. It will protect the privacy of users’ data by allowing the users to set their own privacy policies, and then enforcing them so that no unauthorised access is allowed to their data. The infrastructure ensures that the users’ privacy policies are stuck to their data, so that access will always be controlled by the policies even if the data is transferred between cloud providers or services. This infrastructure also ensures the enforcement of privacy policies which may be written in different policy languages by multiple authorities such as: legal, data subject, data issuer and data controller. A conflict resolution strategy is presented which resolves conflicts among the decisions returned by the different policy decision points (PDPs). The performance figures are presented which show that the system performs well and that each additional PDP only imposes a small overhead
How to securely break into RBAC: the BTG-RBAC model
No full textAccess control models describe frameworks that dictate how subjects (e.g. users) access resources. In the Role-Based Access Control (RBAC) model access to resources is based on the role the user holds within the organization. Although flexible and easier to manage within large-scale authorization frameworks, RBAC is usually a static model where access control decisions have only two output options: Grant or Deny. Break The Glass (BTG) policies can be provided in order to break or override the access controls within an access control policy but in a controlled and justifiable manner. The main objective of this paper is to integrate BTG within the NIST/ANSI RBAC model in a transparent and secure way so that it can be adopted generically in any domain where unanticipated or emergency situations may occur. The new proposed model, called BTG-RBAC, provides a third decision option BTG. This allows break the glass policies to be implemented in any application without any major changes to either the application or the RBAC authorization infrastructure, apart from the decision engine. Finally, in order to validate the model, we discuss how the BTG-RBAC model is being introduced within a Portuguese healthcare institution where the legislation requires that genetic information must be accessed by a restricted group of healthcare professionals. These professionals, advised by the ethical committee, have required and asked for the implementation of the BTG concept in order to comply with the said legislation
Adding Support to XACML for Multi-Domain User to User Dynamic Delegation of Authority
No full textAbstract. We describe adding support for dynamic delegation of authority between users in multiple administrative domains, to the XACML model for authorisation decision making. Delegation of authority is enacted via the issuing of credentials from one user to another, and follows the role based access control model. We present the problems and requirements that such a delegation model demands, the policy elements that are necessary to control the delegation chains and a description of the architected solution. We propose a new conceptual entity called the Credential Validation Service (CVS) to work alongside the XACML PDP. We describe our implementation of the CVS and present performance measurements for validating delegated chains of credentials
Federated Identity Management
No full textAbstract. This paper addresses the topic of federated identity management. It discusses in detail the following topics: what is digital identity, what is identity management, what is federated identity management, Kim Camerons 7 Laws of Identity, how can we protect the users privacy in a federated environment, levels of assurance, some past and present federated identity management systems, and some current research in FIM
Recognition of Authority in Virtual Organisations
No full textA Virtual Organisation (VO) is a temporary alliance of autonomous, diverse, and geographically dispersed organisations, where the participants pool resources, information and knowledge in order to meet common objectives. This requires dynamic security policy management. We propose an authorisation policy management model called recognition of authority (ROA) which allows dynamically trusted authorities to adjust the authorisation policies for VO resources. The model supports dynamic delegation of authority, and the expansion and contraction of organizations in a VO, so that the underlying authorisation system is able to use existing user credentials issued by participating organisations to evaluate the users access rights to VO resources
Instant certificate revocation and publication using WebDAV
No full textThere are several problems associated with the current ways that certificates are published and revoked. This paper discusses these problems, and then proposes a solution based on the use of WebDAV, an enhancement to the HTTP protocol. The proposed solution provides instant certificate revocation, minimizes the processing costs of the certificate issuer and relying party, and eases the administrative burden of publishing certificates and certificate revocation lists (CRLs). We describe how WebDAV can be used for X.509 certificate revocation, and describe how we have implemented it in the PERMIS authorization infrastructure
Energy-Efficient Train Operation: Conclusions and Future Work
No full textThis chapter gives the basic conclusions about energy-efficient train operation covering energy-efficient train driving, energy-efficient train timetabling, regenerative braking, energy storage systems and power supply networks. Future work that will develop energy-efficient train operation further include the interaction of connected driver advisory systems (C-DAS) and automatic train operation (ATO) with railway traffic management systems, cooperative train control in platoons of virtually coupled trains, digital twin technology and particularly its application to power supply systems, and the interaction between the railway network with the electrical power grid and renewable energy generation.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
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