281 research outputs found
Obligations of trust for privacy and confidentiality in distributed transactions
Purpose â This paper aims to describe a bilateral symmetric approach to authorization, privacy protection and obligation enforcement in distributed transactions. The authors introduce the concept of the obligation of trust (OoT) protocol as a privacy assurance and authorization mechanism that is built upon the XACML standard. The OoT allows two communicating parties to dynamically exchange their privacy and authorization requirements and capabilities, which the authors term a notification of obligation (NoB), as well as their commitments to fulfilling each other's requirements, which the authors term signed acceptance of obligations (SAO). The authors seek to describe some applicability of these concepts and to show how they can be integrated into distributed authorization systems for stricter privacy and confidentiality control.
Design/methodology/approach â Existing access control and privacy protection systems are typically unilateral and provider-centric, in that the enterprise service provider assigns the access rights, makes the access control decisions, and determines the privacy policy. There is no negotiation between the client and the service provider about which access control or privacy policy to use. The authors adopt a symmetric, more user-centric approach to privacy protection and authorization, which treats the client and service provider as peers, in which both can stipulate their requirements and capabilities, and hence negotiate terms which are equally acceptable to both parties.
Findings â The authors demonstrate how the obligation of trust protocol can be used in a number of different scenarios to improve upon the mechanisms that are currently available today.
Practical implications â This approach will serve to increase trust in distributed transactions since each communicating party receives a difficult to repudiate digitally signed acceptance of obligations, in a standard language (XACML), which can be automatically enforced by their respective computing machinery.
Originality/value â The paper adds to current research in trust negotiation, privacy protection and authorization by combining all three together into one set of standardized protocols. Furthermore, by providing hard to repudiate signed acceptance of obligations messages, this strengthens the legal case of the injured party should a dispute arise
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Using SHA2 Algorithms with Cryptographic Message Syntax This document describes the conventions for using the Secure Hash Algorithm (SHA) message digest algorithms (SHA-224, SHA-256, SHA-384, SHA-512) with the Cryptographic Message Syntax (CMS). It also describes the conventions for using these algorithms with the CMS an
Assured information sharing for ad-hoc collaboration
Collaborative information sharing tends to be highly dynamic and often ad hoc among organizations. The dynamic natures and sharing patterns in ad-hoc collaboration impose a need for a comprehensive and flexible approach to reflecting and coping with the unique access control requirements associated with the environment.
This dissertation outlines a Role-based Access Management for Ad-hoc Resource Shar- ing framework (RAMARS) to enable secure and selective information sharing in the het- erogeneous ad-hoc collaborative environment. Our framework incorporates a role-based approach to addressing originator control, delegation and dissemination control. A special trust-aware feature is incorporated to deal with dynamic user and trust management, and a novel resource modeling scheme is proposed to support fine-grained selective sharing of composite data. As a policy-driven approach, we formally specify the necessary pol- icy components in our framework and develop access control policies using standardized eXtensible Access Control Markup Language (XACML). The feasibility of our approach is evaluated in two emerging collaborative information sharing infrastructures: peer-to- peer networking (P2P) and Grid computing. As a potential application domain, RAMARS framework is further extended and adopted in secure healthcare services, with a unified patient-centric access control scheme being proposed to enable selective and authorized sharing of Electronic Health Records (EHRs), accommodating various privacy protection requirements at different levels of granularity
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
Identidade digital federada globaliD
Mestrado em Engenharia de Computadores e TelemåticaO presente texto propÔe uma solução para a gestão de identidade digital
online tendo em conta a versatilidade, o anonimato, a privacidade, a
veracidade, a credibilidade e a responsabilidade do utilizador, recorrendo para
isso ao uso do CartĂŁo de CidadĂŁo ElectrĂłnico Nacional PortuguĂȘs e a outros
meios de autenticação pĂșblicos usados diariamente pelos utilizadores. A
dissertação é composta pela apresentação do conceito de identidade e das
suas particularidades, por uma anĂĄlise aos vĂĄrios problemas da gestĂŁo da
informação pessoal online, uma anålise aos vårios modelos, mecanismos e
especificaçÔes existentes para gerir a identidade digital online (gestão de
identidade digital). Uma solução de gestão de identidade digital baseada no
modelo de identidade federada e associada ao CartĂŁo do CidadĂŁo ElectrĂłnico
Nacional PortuguĂȘs Ă© apresentada, descrita, analisada, avaliada e comparada
com outras soluçÔes existentes.
Por fim um protĂłtipo de um provedor de identidades digitais federadas
baseado na solução de gestão de identidade digital proposta é apresentado.The following text provides a solution for the digital identity management on the
Web regarding the usersâ versatility, anonymity, privacy, veracity,
trustworthiness and accountability by using the Portuguese National Electronic
Citizen Identity Card and other publicly available authentication mechanisms
users use daily. The dissertation consists of the presentation of the concept of
identity and its particularities, an analysis to the several problems of managing
personal information online, and an analysis to the several existing models,
mechanisms and specifications for the management of the digital identity online
(digital identity management). A solution for digital identity management based
on the federated identity model and associated to the Portuguese National
Electronic Citizen Identity Card is introduced, described, analyzed, evaluated
and compared to other several existing solutions. Last, a prototype of a
federated digital identity provider based on the purposed solution for digital
identity management is presented
Contributions to the privacy provisioning for federated identity management platforms
Identity information, personal data and userâs profiles are key assets for organizations
and companies by becoming the use of identity management (IdM) infrastructures a prerequisite
for most companies, since IdM systems allow them to perform their business
transactions by sharing information and customizing services for several purposes in more
efficient and effective ways.
Due to the importance of the identity management paradigm, a lot of work has been done
so far resulting in a set of standards and specifications. According to them, under the
umbrella of the IdM paradigm a personâs digital identity can be shared, linked and reused
across different domains by allowing users simple session management, etc. In this way,
usersâ information is widely collected and distributed to offer new added value services
and to enhance availability. Whereas these new services have a positive impact on usersâ
life, they also bring privacy problems.
To manage usersâ personal data, while protecting their privacy, IdM systems are the ideal
target where to deploy privacy solutions, since they handle usersâ attribute exchange.
Nevertheless, current IdM models and specifications do not sufficiently address comprehensive
privacy mechanisms or guidelines, which enable users to better control over the
use, divulging and revocation of their online identities. These are essential aspects, specially
in sensitive environments where incorrect and unsecured management of userâs data
may lead to attacks, privacy breaches, identity misuse or frauds.
Nowadays there are several approaches to IdM that have benefits and shortcomings, from
the privacy perspective.
In this thesis, the main goal is contributing to the privacy provisioning for federated
identity management platforms. And for this purpose, we propose a generic architecture
that extends current federation IdM systems. We have mainly focused our contributions
on health care environments, given their particularly sensitive nature. The two main
pillars of the proposed architecture, are the introduction of a selective privacy-enhanced
user profile management model and flexibility in revocation consent by incorporating an
event-based hybrid IdM approach, which enables to replace time constraints and explicit
revocation by activating and deactivating authorization rights according to events. The
combination of both models enables to deal with both online and offline scenarios, as well
as to empower the user role, by letting her to bring together identity information from
different sources.
Regarding userâs consent revocation, we propose an implicit revocation consent mechanism
based on events, that empowers a new concept, the sleepyhead credentials, which
is issued only once and would be used any time. Moreover, we integrate this concept
in IdM systems supporting a delegation protocol and we contribute with the definition
of mathematical model to determine event arrivals to the IdM system and how they are
managed to the corresponding entities, as well as its integration with the most widely
deployed specification, i.e., Security Assertion Markup Language (SAML).
In regard to user profile management, we define a privacy-awareness user profile management
model to provide efficient selective information disclosure. With this contribution a
service provider would be able to accesses the specific personal information without being
able to inspect any other details and keeping user control of her data by controlling
who can access. The structure that we consider for the user profile storage is based on
extensions of Merkle trees allowing for hash combining that would minimize the need of
individual verification of elements along a path. An algorithm for sorting the tree as we
envision frequently accessed attributes to be closer to the root (minimizing the accessâ
time) is also provided.
Formal validation of the above mentioned ideas has been carried out through simulations
and the development of prototypes. Besides, dissemination activities were performed in
projects, journals and conferences.Programa Oficial de Doctorado en IngenierĂa TelemĂĄticaPresidente: MarĂa Celeste Campo VĂĄzquez.- Secretario: MarĂa Francisca Hinarejos Campos.- Vocal: Ăscar Esparza MartĂ
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