6,131 research outputs found
A Declarative Framework for Specifying and Enforcing Purpose-aware Policies
Purpose is crucial for privacy protection as it makes users confident that
their personal data are processed as intended. Available proposals for the
specification and enforcement of purpose-aware policies are unsatisfactory for
their ambiguous semantics of purposes and/or lack of support to the run-time
enforcement of policies.
In this paper, we propose a declarative framework based on a first-order
temporal logic that allows us to give a precise semantics to purpose-aware
policies and to reuse algorithms for the design of a run-time monitor enforcing
purpose-aware policies. We also show the complexity of the generation and use
of the monitor which, to the best of our knowledge, is the first such a result
in literature on purpose-aware policies.Comment: Extended version of the paper accepted at the 11th International
Workshop on Security and Trust Management (STM 2015
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GRIDCC: Real-time workflow system
The Grid is a concept which allows the sharing of resources between distributed communities, allowing each to progress towards potentially different goals. As adoption of the Grid increases so are the activities that people wish to conduct through it. The GRIDCC project is a European Union funded project addressing the issues of integrating instruments into the Grid. This increases the requirement of workflows and Quality of Service upon these workflows as many of these instruments have real-time requirements. In this paper we present the workflow management service within the GRIDCC project which is tasked with optimising the workflows and ensuring that they meet the pre-defined QoS requirements specified upon them
Secure data sharing and processing in heterogeneous clouds
The extensive cloud adoption among the European Public Sector Players empowered them to own and operate a range of cloud infrastructures. These deployments vary both in the size and capabilities, as well as in the range of employed technologies and processes. The public sector, however, lacks the necessary technology to enable effective, interoperable and secure integration of a multitude of its computing clouds and services. In this work we focus on the federation of private clouds and the approaches that enable secure data sharing and processing among the collaborating infrastructures and services of public entities. We investigate the aspects of access control, data and security policy languages, as well as cryptographic approaches that enable fine-grained security and data processing in semi-trusted environments. We identify the main challenges and frame the future work that serve as an enabler of interoperability among heterogeneous infrastructures and services. Our goal is to enable both security and legal conformance as well as to facilitate transparency, privacy and effectivity of private cloud federations for the public sector needs. © 2015 The Authors
Context-Aware and Secure Workflow Systems
Businesses do evolve. Their evolution necessitates the re-engineering of their existing "business processesâ, with the objectives of reducing costs, delivering services on time, and enhancing their profitability in a competitive market. This is generally true and particularly in domains such as manufacturing, pharmaceuticals and education). The central objective of workflow technologies is to separate business policies (which normally are encoded in business logics) from the underlying business applications. Such a separation is desirable as it improves the evolution of business processes and, more often than not, facilitates the re-engineering at the organisation level without the need to detail knowledge or analyses of the application themselves. Workflow systems are currently used by many organisations with a wide range of interests and specialisations in many domains. These include, but not limited to, office automation, finance and banking sector, health-care, art, telecommunications, manufacturing and education. We take the view that a workflow is a set of "activitiesâ, each performs a piece of functionality within a given "contextâ and may be constrained by some security requirements. These activities are coordinated to collectively achieve a required business objective. The specification of such coordination is presented as a set of "execution constraintsâ which include parallelisation (concurrency/distribution), serialisation, restriction, alternation, compensation and so on. Activities within workflows could be carried out by humans, various software based application programs, or processing entities according to the organisational rules, such as meeting deadlines or performance improvement. Workflow execution can involve a large number of different participants, services and devices which may cross the boundaries of various organisations and accessing variety of data.
This raises the importance of
_ context variations and context-awareness and
_ security (e.g. access control and privacy).
The specification of precise rules, which prevent unauthorised participants from executing sensitive tasks and also to prevent tasks from accessing unauthorised services or (commercially) sensitive information, are crucially important. For example, medical scenarios will require that:
_ only authorised doctors are permitted to perform certain tasks,
_ a patient medical records are not allowed to be accessed by anyone without
the patient consent and
_ that only specific machines are used to perform given tasks at a given time.
If a workflow execution cannot guarantee these requirements, then the flow will
be rejected. Furthermore, features/characteristics of security requirement are both
temporal- and/or event-related. However, most of the existing models are of a
static nature â for example, it is hard, if not impossible, to express security requirements which are:
_ time-dependent (e.g. A customer is allowed to be overdrawn by 100 pounds
only up-to the first week of every month.
_ event-dependent (e.g. A bank account can only be manipulated by its owner unless there is a change in the law or after six months of his/her death).
Currently, there is no commonly accepted model for secure and context-aware workflows or even a common agreement on which features a workflow security model should support. We have developed a novel approach to design, analyse and validate workflows. The approach has the following components:
= A modelling/design language (known as CS-Flow).
The language has the following features:
â support concurrency;
â context and context awareness are first-class citizens;
â supports mobility as activities can move from one context to another;
â has the ability to express timing constrains: delay, deadlines, priority and schedulability;
â allows the expressibility of security policies (e.g. access control and privacy) without the need for extra linguistic complexities; and
â enjoy sound formal semantics that allows us to animate designs and compare various designs.
= An approach known as communication-closed layer is developed, that allows us to serialise a highly distributed workflow to produce a semantically equivalent quasi-sequential flow which is easier to understand and analyse. Such re-structuring, gives us a mechanism to design fault-tolerant workflows as layers are atomic activities and various existing forward and backward error recovery techniques can be deployed.
= Provide a reduction semantics to CS-Flow that allows us to build a tool support to animate a specifications and designs. This has been evaluated on a Health care scenario, namely the Context Aware Ward (CAW) system. Health care provides huge amounts of business workflows, which will benefit from workflow adaptation and support through pervasive computing systems. The evaluation takes two complementary strands:
â provide CS-Flowâs models and specifications and
â formal verification of time-critical component of a workflow
The Design and Analysis of Context-Aware, Secure Workflow Systems
Workflows are set of activities that implement and realise business
goals. Modern business goals add extra requirements on workflow systems and their
management. Workflows may cross many organisations and utilise services on a
variety of devices and/or supported by different platforms. Current workflows are
therefore inherently context-aware. Each context is governed and constrained by its
own policies and rules to prevent unauthorised participants from executing sensitive
tasks and also to prevent tasks from accessing unauthorised services and/or data. We
present a sound and multi-layered design language for the design and analysis of
secure and context aware workflows systems
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Designing Secure Service Workflows in BPEL
This paper presents an approach that we have developed to support the design of secure service based applications in BPEL. The approach is based on the use of secure service composition patterns, which are proven to preserve composition level security properties if the services that are composed according to the pattern satisfy other properties individually. The secure service composition patterns are used for two purposes: (a) to analyse whether a given workflow fragment satisfies a given security property, and (b) to generate com-positions of services that could substitute for individual services within the workflow that cause the violation of the security properties. Our approach has been implemented in a tool that is based on Eclipse BPEL Designer
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