91 research outputs found
A Novel Framework for Big Data Security Infrastructure Components
Big data encompasses enormous data and management of huge data collected from various sources like online social media contents, log files, sensor records, surveys and online transactions. It is essential to provide new security models, concerns and efficient security designs and approaches for confronting security and privacy aspects of the same. This paper intends to provide initial analysis of the security challenges in Big Data. The paper introduces the basic concepts of Big Data and its enormous growth rate in terms of pita and zettabytes. A model framework for Big Data Infrastructure Security Components Framework (BDAF) is proposed that includes components like Security Life Cycle, Fine-grained data-centric access control policies, the Dynamic Infrastructure Trust Bootstrap Protocol (DITBP). The framework allows deploying trusted remote virtualised data processing environment and federated access control and identity management
Service-oriented models for audiovisual content storage
What are the important topics to understand if involved with storage services to hold digital audiovisual content? This report takes a look at how content is created and moves into and out of storage; the storage service value networks and architectures found now and expected in the future; what sort of data transfer is expected to and from an audiovisual archive; what transfer protocols to use; and a summary of security and interface issues
Dynamic trust negotiation for decentralised e-health collaborations
In the Internet-age, the geographical boundaries that have previously impinged upon inter-organisational collaborations have become decreasingly important. Of more importance for such collaborations is the notion and subsequent nature of security and trust - this is especially so in open collaborative environments like the Grid where resources can be both made available, subsequently accessed and used by remote users from a multitude of institutions with a variety of different privileges spanning across the collaboration. In this context, the ability to dynamically negotiate and subsequently enforce security policies driven by various levels of inter-organisational trust is essential.
Numerous access control solutions exist today to address aspects of inter-organisational security. These include the use of centralised access control lists where all collaborating partners negotiate and agree on privileges required to access shared resources. Other solutions involve delegating aspects of access right management to trusted remote individuals in assigning privileges to their (remote) users. These solutions typically entail negotiations and delegations which are constrained by organisations, people and the static rules they impose. Such constraints often result in a lack of flexibility in what has been agreed; difficulties in reaching agreement, or once established, in subsequently maintaining these agreements. Furthermore, these solutions often reduce the autonomous capacity of collaborating organisations because of the need to satisfy collaborating partners demands. This can result in increased security risks or reducing the granularity of security policies.
Underpinning this is the issue of trust. Specifically trust realisation between organisations, between individuals, and/or between entities or systems that are present in multi-domain authorities. Trust negotiation is one approach that allows and supports trust realisation. The thesis introduces a novel model called dynamic trust negotiation (DTN) that supports n-tier negotiation hops for trust realisation in multi-domain collaborative environments with specific focus on e-Health environments. DTN describes how trust pathways can be discovered and subsequently how remote security credentials can be mapped to local security credentials through trust contracts, thereby bridging the gap that makes decentralised security policies difficult to define and enforce. Furthermore, DTN shows how n-tier negotiation hops can limit the disclosure of access control policies and how semantic issues that exist with security attributes in decentralised environments can be reduced. The thesis presents the results from the application of DTN to various clinical trials and the implementation of DTN to Virtual Organisation for Trials of Epidemiological Studies (VOTES). The thesis concludes that DTN can address the issue of realising and establishing trust between systems or agents within the e-Health domain, such as the clinical trials domain
Security Mechanisms for Workflows in Service-Oriented Architectures
Die Arbeit untersucht, wie sich Unterstützung für Sicherheit und Identitätsmanagement in ein Workflow-Management-System integrieren lässt. Basierend auf einer Anforderungsanalyse anhand eines Beispiels aus der beruflichen Weiterbildung und einem Abgleich mit dem Stand der Technik wird eine Architektur für die sichere Ausführung von Workflows und die Integration mit Identitätsmanagement-Systemen entwickelt, die neue Anwendungen mit verbesserter Sicherheit und Privatsphäre ermöglicht
Trust negotiation policy management for service-oriented applications
Service-oriented architectures (SOA), and in particular Web services, have quickly become a popular technology to
connect applications both within and across enterprise boundaries. However, as services are increasingly used to
implement critical functionality, security has become an important concern impeding the widespread adoption of SOA.
Trust negotiation is an approach to access control that may be applied in scenarios where service requesters are often
unknown in advance, such as for services available via the public Internet. Rather than relying on requesters'
identities, trust negotiation makes access decisions based on the level of trust established between the requester and
the provider in a negotiation, during which the parties exchange credentials, which are signed assertions that describe
some attributes of the owner.
However, managing the evolution of trust negotiation policies is a difficult problem that has not been sufficiently
addressed to date. Access control policies have a lifecycle, and they are revised based on applicable business
policies. Additionally, because a trust relationship established in a trust negotiation may be long lasting, their
evolution must also be managed. Simply allowing a negotiation to continue according to an old policy may be
undesirable, especially if new important constraints have been added.
In this thesis, we introduce a model-driven trust negotiation framework for service-oriented applications. The
framework employs a model for trust negotiation, based on state machines, that allows automated generation of the
control structures necessary to enforce trust negotiation policies from the visual model of the policy. Our policy
model also supports lifecycle management. We provide sets of operations to modify policies and to manage ongoing
negotiations, and operators for identifying and managing impacts of changes to trust negotiation policies on ongoing
trust negotiations.
The framework presented in the thesis has been implemented in the Trust-Serv prototype, which leverages industry
specifications such as WS-Security and WS-Trust to offer a container-centric mechanism for deploying trust negotiation
that is transparent to the services being protected
A Dynamic Access Control Model Using Authorising Workfow and Task Role-based Access Control
Access control is fundamental and prerequisite to govern and safeguard information assets within an organisation. Organisations generally use Web enabled remote access coupled with applications access distributed across various networks. These networks face various challenges including increase operational burden and monitoring issues due to the dynamic and complex nature of security policies for access control. The increasingly dynamic nature of collaborations means that in one context a user should have access to sensitive information, whilst not being allowed access in other contexts. The current access control models are static and lack Dynamic Segregation of Duties (SoD), Task instance level of Segregation, and decision making in real time. This thesis addresses these limitations describes tools to support access management in borderless network environments with dynamic SoD capability and real time access control decision making and policy enforcement. This thesis makes three contributions: i) Defining an Authorising Workflow Task Role Based Access Control (AW-TRBAC) using existing task and workflow concepts. This new workflow integrates dynamic SoD, whilst considering task instance restriction to ensure overall access governance and accountability. It enhances existing access control models such as Role Based Access Control (RBAC) by dynamically granting users access rights and providing access governance. ii) Extension of the OASIS standard of XACML policy language to support dynamic access control requirements and enforce access control rules for real time decision making. This mitigates risks relating to access control, such as escalation of privilege in broken access control, and insucient logging and monitoring. iii) The AW-TRBAC model is implemented by extending the open source XACML (Balana) policy engine to demonstrate its applicability to a real industrial use case from a financial institution. The results show that AW-TRBAC is scalable, can process relatively large numbers of complex requests, and meets the requirements of real time access control decision making, governance and mitigating broken access control risk
User-controlled access management to resources on the Web
PhD ThesisThe rapidly developing Web environment provides users with a wide set of rich services as
varied and complex as desktop applications. Those services are collectively referred to as "Web
2.0", with such examples as Facebook, Google Apps, Salesforce, or Wordpress, among many
others. These applications are used for creating, managing, and sharing online data between
users and services on the Web. With the shift from desktop computers to the Web, users create
and store more of their data online and not on the hard drives of their computers. This data
includes personal information, documents, photos, as well as other resources. Irrespective of
the environment, either desktop or the Web, it is the user who creates the data, who disseminates
it and who shares this data. On the Web, however, sharing resources poses new security
and usability challenges which were not present in traditional computing. Access control, also
known as authorisation, that aims to protect such sharing, is currently poorly addressed in this
environment. Existing access control is often not well suited to the increasing amount of highly
distributed Web data and does not give users the required flexibility in managing their data.
This thesis discusses new solutions to access control for the Web. Firstly, it shows a proposal
named User-Managed Access Control (UMAC) and presents its architecture and protocol. This
thesis then focuses on the User-Managed Access (UMA) solution that is researched by the User-
Managed Access Work Group at Kantara Initiative. The UMA approach allows the user to
play a pivotal role in assigning access rights to their resources which may be spread across
multiple cloud-based Web applications. Unlike existing authorisation systems, it relies on a
user’s centrally located security requirements for these resources. The security requirements are
expressed in the form of access control policies and are stored and evaluated in a specialised
component called Authorisation Manager. Users are provided with a consistent User Experience
for managing access control for their distributed online data and are provided with a holistic
view of the security applied to this data. Furthermore, this thesis presents the software that
implements the UMA proposal. In particular, this thesis shows frameworks that allow Web
applications to delegate their access control function to an Authorisation Manager. It also
presents design and implementation of an Authorisation Manager and discusses its evaluation
conducted with a user study. It then discusses design and implementation of a second, improved
Authorisation Manager. Furthermore, this thesis presents the applicability of the UMA approach
and the implemented software to real-world scenarios
Evolving a secure grid-enabled, distributed data warehouse : a standards-based perspective
As digital data-collection has increased in scale and number, it becomes an important type of resource serving a wide community of researchers. Cross-institutional data-sharing and collaboration introduce a suitable approach to facilitate those research institutions that are suffering the lack of data and related IT infrastructures. Grid computing has become a widely adopted approach to enable cross-institutional resource-sharing and collaboration. It integrates a distributed and heterogeneous collection of locally managed users and resources. This project proposes a distributed data warehouse system, which uses Grid technology to enable data-access and integration, and collaborative operations across multi-distributed institutions in the context of HV/AIDS research. This study is based on wider research into OGSA-based Grid services architecture, comprising a data-analysis system which utilizes a data warehouse, data marts, and near-line operational database that are hosted by distributed institutions. Within this framework, specific patterns for collaboration, interoperability, resource virtualization and security are included. The heterogeneous and dynamic nature of the Grid environment introduces a number of security challenges. This study also concerns a set of particular security aspects, including PKI-based authentication, single sign-on, dynamic delegation, and attribute-based authorization. These mechanisms, as supported by the Globus Toolkit’s Grid Security Infrastructure, are used to enable interoperability and establish trust relationship between various security mechanisms and policies within different institutions; manage credentials; and ensure secure interactions
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