A Secure Task Delegation Model for Workflows

International audienceWorkflow management systems provide some of the required technical means to preserve integrity, confidentiality and availability at the control-, data- and task assignment layers of a workflow. We currently observe a move away from predefined strict workflow enforcement approaches towards supporting exceptions which are difficult to foresee when modelling a workflow. One specific approach for exception handling is that of task delegation. The delegation of a task from one principal to another, however, has to be managed and executed in a secure way, in this context implying the presence of a fixed set of delegation events. In this paper, we propose first and foremost, a secure task delegation model within a workflow. The novel part of this model is separating the various aspects of delegation with regards tousers, tasks, events and data, portraying them in terms of a multi-layered state machine. We then define delegation scenarios and analyse additional requirements to support secure task delegation over these layers. Moreover, we detail a delegation protocol with a specific focus on the initial negotiation steps between the involved principals

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

An Approach for Managing Access to Personal Information Using Ontology-Based Chains

The importance of electronic healthcare has caused numerous changes in both substantive and procedural aspects of healthcare processes. These changes have produced new challenges to patient privacy and information secrecy. Traditional privacy policies cannot respond to rapidly increased privacy needs of patients in electronic healthcare. Technically enforceable privacy policies are needed in order to protect patient privacy in modern healthcare with its cross organisational information sharing and decision making. This thesis proposes a personal information flow model that specifies a limited number of acts on this type of information. Ontology classified Chains of these acts can be used instead of the "intended/business purposes" used in privacy access control to seamlessly imbuing current healthcare applications and their supporting infrastructure with security and privacy functionality. In this thesis, we first introduce an integrated basic architecture, design principles, and implementation techniques for privacy-preserving data mining systems. We then discuss the key methods of privacypreserving data mining systems which include four main methods: Role based access control (RBAC), Hippocratic database, Chain method and eXtensible Access Control Markup Language (XACML). We found out that the traditional methods suffer from two main problems: complexity of privacy policy design and the lack of context flexibility that is needed while working in critical situations such as the one we find in hospitals. We present and compare strategies for realising these methods. Theoretical analysis and experimental evaluation show that our new method can generate accurate data mining models and safe data access management while protecting the privacy of the data being mined. The experiments followed comparative kind of experiments, to show the ease of the design first and then follow real scenarios to show the context flexibility in saving personal information privacy of our investigated method

Context-Aware and Secure Workflow Systems

Businesses do evolve. Their evolution necessitates the re-engineering of their existing "business processes”, 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 "activities”, each performs a piece of functionality within a given "context” 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 constraints” 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 – 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: – support concurrency; – context and context awareness are first-class citizens; – supports mobility as activities can move from one context to another; – has the ability to express timing constrains: delay, deadlines, priority and schedulability; – allows the expressibility of security policies (e.g. access control and privacy) without the need for extra linguistic complexities; and – 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: – provide CS-Flow’s models and specifications and – formal verification of time-critical component of a workflow

Identity-as-a-Service: An Adaptive Security Infrastructure and Privacy-Preserving User Identity for the Cloud Environment

In recent years, enterprise applications have begun to migrate from a local hosting to a cloud provider and may have established a business-to-business relationship with each other manually. Adaptation of existing applications requires substantial implementation changes in individual architectural components. On the other hand, users may store their Personal Identifiable Information (PII) in the cloud environment so that cloud services may access and use it on demand. Even if cloud services specify their privacy policies, we cannot guarantee that they follow their policies and will not (accidentally) transfer PII to another party. In this paper, we present Identity-as-a-Service (IDaaS) as a trusted Identity and Access Management with two requirements: Firstly, IDaaS adapts trust between cloud services on demand. We move the trust relationship and identity propagation out of the application implementation and model them as a security topology. When the business comes up with a new e-commerce scenario, IDaaS uses the security topology to adapt a platform-specific security infrastructure for the given business scenario at runtime. Secondly, we protect the confidentiality of PII in federated security domains. We propose our Purpose-based Encryption to protect the disclosure of PII from intermediary entities in a business transaction and from untrusted hosts. Our solution is compliant with the General Data Protection Regulation and involves the least user interaction to prevent identity theft via the human link. The implementation can be easily adapted to existing Identity Management systems, and the performance is fast.</jats:p

Using agreements as an abstraction for access control administration

The last couple of decades saw lots of changes in the business world. Not only did technology change at a rapid pace, but businesses' views with respect to the role that information plays also changed drastically. Information is now seen as a strategic resource. This change paved the way for the so-called knowledge worker that not only consumes information, but actively participates in creating new knowledge from information. Employees must therefore be empowered to fulfill their new role as knowledge workers. Empowerment happens through job redefinition and by ensuring that the appropriate information is at hand. Although information is more readily available to employees, appropriate access controls must still be implemented. However, there is conflict between the need to share information and the need to keep information confidential. These conflicting needs must be reflected in the administration of access control. In order to resolve these conflicts, a finer granularity of access controls must be implemented. However, to implement a finer granularity of access control, an increase in the number of access controls and, therefore, the administrative burden is inevitable. Access control administrators must cater for a potentially large number of systems. These systems can not only be heterogenous as far as architecture and technology are concerned, but also with respect to access control paradigms. Vendors have realized that human involvement must be minimized, giving birth to so-called "provisioning systems". Provisioning systems, in principle, automate certain parts of access control administration. However, currently implementations are done in an ad hoc manner, that is, without a systematic process of identifying the real access control needs. This study aims to address this problem by proposing the "agreement abstraction" as a possible vehicle for systematically analyzing the access control requirements in a business. In essence, the agreement abstraction allows us to identify opportunities where access control can be automated. A specific methodological approach is suggested whereby the business is analysed in terms of business processes, as opposed to the more traditional resource perspective. Various business processes are used as examples to explain and motivate the proposed agreement abstraction further. This dissertation therefore contributes to the field of discourse by presenting a new abstraction that can be used systematically to analyse access control administration requirements

Modellierung ortsabhängiger Zugriffskontrolle für mobile Geschäftsprozesse

Der Einsatz mobiler Computer wie Smartphones für die Abarbeitung mobiler Geschäftsprozesse bringt neben großen Vorteilen auch spezifische Sicherheitsherausforderungen mit sich. Als ein Lösungsansatz hierfür wird "ortsabhängige Zugriffskontrolle" verfolgt. Die Grundidee dabei ist es, den aktuellen Aufenthaltsort des Nutzers für die Zugriffskontrollentscheidung auszuwerten. Zur Modellierung solcher Ortseinschränkungen wird eine auf UML-Aktivitätsdiagrammen aufbauende Notation eingeführt

High-Performance Modelling and Simulation for Big Data Applications

This open access book was prepared as a Final Publication of the COST Action IC1406 “High-Performance Modelling and Simulation for Big Data Applications (cHiPSet)“ project. Long considered important pillars of the scientific method, Modelling and Simulation have evolved from traditional discrete numerical methods to complex data-intensive continuous analytical optimisations. Resolution, scale, and accuracy have become essential to predict and analyse natural and complex systems in science and engineering. When their level of abstraction raises to have a better discernment of the domain at hand, their representation gets increasingly demanding for computational and data resources. On the other hand, High Performance Computing typically entails the effective use of parallel and distributed processing units coupled with efficient storage, communication and visualisation systems to underpin complex data-intensive applications in distinct scientific and technical domains. It is then arguably required to have a seamless interaction of High Performance Computing with Modelling and Simulation in order to store, compute, analyse, and visualise large data sets in science and engineering. Funded by the European Commission, cHiPSet has provided a dynamic trans-European forum for their members and distinguished guests to openly discuss novel perspectives and topics of interests for these two communities. This cHiPSet compendium presents a set of selected case studies related to healthcare, biological data, computational advertising, multimedia, finance, bioinformatics, and telecommunications

Konfigurierbare Visualisierung komplexer Prozessmodelle

Die in heutigen Unternehmen durch Informationssysteme unterstützten Geschäftsprozesse werden zunehmend komplexer. Häufig existieren keine zentralen Steuereinheiten, sondern die Ausführung eines Prozesses ist auf viele heterogene Systeme verteilt. Ohne entsprechende Werkzeugunterstützung ist es daher schwer, einen Überblick über den aktuellen Ausführungsstatus solcher fragmentierter Prozesse zu bewahren. Eine Visualisierungskomponente, welche die Prozesse (inkl. relevanter Applikationsdaten) durchgängig darstellt, ist hier essenziell. Allerdings muss eine solche Komponente in der Lage sein, die Informationsbedürfnisse der verschiedenen Benutzergruppen adäquat zu befriedigen. Typischerweise gibt es hier unterschiedliche Anforderungen an eine Prozessvisualisierung im Hinblick auf Detaillierungsgrad, angezeigte Daten und graphische Informationsaufbereitung. Heutige Werkzeuge stellen Prozesse meist in exakt derselben Form dar, wie sie vom Prozessmodellierer ursprünglich gezeichnet worden sind. Eine flexible Anpassung der Darstellung an die Bedürfnisse des Betrachters ist nicht oder nur in sehr engen Grenzen möglich. Diese Arbeit stellt mit Proviado ein Rahmenwerk für die konfigurierbare Visualisierung komplexer Prozesse vor. Proviado ermöglicht sowohl eine strukturelle als auch eine graphische Anpassung der Prozessvisualisierung. Mit Hilfe eines mächtigen View-Mechanismus können Prozessmodelle strukturell an die Bedürfnisse ihrer Betrachter angepasst werden, indem Prozesselemente reduziert oder zu abstrakten Elementen aggregiert werden. Es werden View-Bildungsoperationen bereitgestellt, die in mehreren Schichten organisiert sind. Mittels Konfigurationsparametern, die die Eigenschaften der resultierenden Prozessmodelle beeinflussen, kann die View-Bildung flexibel konfiguriert und an die Bedürfnisse des jeweiligen Anwendungsfalls angepasst werden. Weitere Möglichkeiten zur graphischen Konfiguration einer Prozessvisualisierung bietet ein fortschrittlicher Template-Mechanismus. Zum einen können die für die Visualisierung zu verwendenden Symbole einfach definiert werden. Zum anderen erlaubt dieser Mechanismus eine flexible Zuordnung der Symbole einer Prozessnotation zu Prozesselementen. Diese Zuordnung kann entweder statisch (z.B. abhängig vom Prozesselementtyp) oder dynamisch, d.h. abhängig von Laufzeitdaten (z.B. Ausführungszustand), erfolgen. Diese beiden Basismechanismen werden ergänzt um Konzepte, die für die Realisierung einer umfassenden Visualisierungskomponente unverzichtbar sind. Dazu zählen unter anderem die Anbindung prozessunterstützender Systeme (d.h. die Integration von Modell- und Laufzeitdaten) sowie Konzepte für das automatische Layout dynamisch berechneter Prozessgraphen. Insgesamt können mit Proviado Prozessvisualisierungen strukturell und graphisch an die Bedürfnisse des jeweiligen Betrachters angepasst werden. Die entsprechenden Darstellungen bieten allen in die Prozesse involvierten Personen eine wesentlich bessere Unterstützung bei der täglichen Arbeit als derzeit verfügbare Systeme