Hierarchical Group and Attribute-Based Access Control: Incorporating Hierarchical Groups and Delegation into Attribute-Based Access Control

Attribute-Based Access Control (ABAC) is a promising alternative to traditional models of access control (i.e. Discretionary Access Control (DAC), Mandatory Access Control (MAC) and Role-Based Access control (RBAC)) that has drawn attention in both recent academic literature and industry application. However, formalization of a foundational model of ABAC and large-scale adoption is still in its infancy. The relatively recent popularity of ABAC still leaves a number of problems unexplored. Issues like delegation, administration, auditability, scalability, hierarchical representations, etc. have been largely ignored or left to future work. This thesis seeks to aid in the adoption of ABAC by filling in several of these gaps. The core contribution of this work is the Hierarchical Group and Attribute-Based Access Control (HGABAC) model, a novel formal model of ABAC which introduces the concept of hierarchical user and object attribute groups to ABAC. It is shown that HGABAC is capable of representing the traditional models of access control (MAC, DAC and RBAC) using this group hierarchy and that in many cases it’s use simplifies both attribute and policy administration. HGABAC serves as the basis upon which extensions are built to incorporate delegation into ABAC. Several potential strategies for introducing delegation into ABAC are proposed, categorized into families and the trade-offs of each are examined. One such strategy is formalized into a new User-to-User Attribute Delegation model, built as an extension to the HGABAC model. Attribute Delegation enables users to delegate a subset of their attributes to other users in an off-line manner (not requiring connecting to a third party). Finally, a supporting architecture for HGABAC is detailed including descriptions of services, high-level communication protocols and a new low-level attribute certificate format for exchanging user and connection attributes between independent services. Particular emphasis is placed on ensuring support for federated and distributed systems. Critical components of the architecture are implemented and evaluated with promising preliminary results. It is hoped that the contributions in this research will further the acceptance of ABAC in both academia and industry by solving the problem of delegation as well as simplifying administration and policy authoring through the introduction of hierarchical user groups

Attribute Based Cryptographic Enforcements for Security and Privacy in E-health Environments

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Protection of Information and Communications in Distributed Systems and Microservices

Distributed systems have been a topic of discussion since the 1980s, but the adoption of microservices has raised number of system components considerably. With more decentralised distributed systems, new ways to handle authentication, authorisation and accounting (AAA) are needed, as well as ways to allow components to communicate between themselves securely. New standards and technologies have been created to deal with these new requirements and many of them have already found their way to most used systems and services globally. After covering AAA and separate access control models, we continue with ways to secure communications between two connecting parties, using Transport Layer Security (TLS) and other more specialised methods such as the Google-originated Secure Production Identity Framework for Everyone (SPIFFE). We also discuss X.509 certificates for ensuring identities. Next, both older time- tested and newer distributed AAA technologies are presented. After this, we are looking into communication between distributed components with both synchronous and asynchronous communication mechanisms, as well as into the publish/subscribe communication model popular with the rise of the streaming platform. This thesis also explores possibilities in securing communications between distributed endpoints and ways to handle AAA in a distributed context. This is showcased in a new software component that handles authentication through a separate identity endpoint using the OpenID Connect authentication protocol and stores identity in a Javascript object-notation formatted and cryptographically signed JSON Web Token, allowing stateless session handling as the token can be validated by checking its signature. This enables fast and scalable session management and identity handling for any distributed system

RBAC seguro, dinâmico e distribuído para aplicações relacionais

Mestrado em Engenharia de Computadores e TelemáticaNowadays, database application use tools like Java Database Connectivity, Hibernate or ADO.NET to access data stored in databases. These tools are designed to bring together the relational database and object-oriented programming paradigms, forsaking applied access control policies. Hence, the application developers must master the established policies as a means to develop software that is conformant with the established access control policies. Furthermore, there are situations where these policies can evolve dynamically. In these cases it becomes hard to adjust the access control mechanisms. This challenge has led to the development of an extension to the role based access control (RBAC) model where permissions are defined as a sequence of create, read, update and delete (CRUD) expressions that can be executed and the interfaces to access them. From these permissions it's possible to generate security artefacts on the client side, i.e. in a distributed manner, which allows the clients to access the stored data while satisfying the security policies defined. On top of this model extension, a security layer has also been created in order to make the access control secure and obligatory. For the RBAC model extension this work leverages a previous work that created a dynamic access control architecture for relational applications, here referred to as DACA (Dynamic Access Control Architecture). DACA uses business logic information and the defined access control policies to build dynamically the security artefacts for the applications. In situations where the access control policies can evolve dynamically, the security artefacts are adjusted automatically. This base work, however, defines as permissions CRUD expressions, which can be executed in any order, and needs an adequate security layer to authenticate users and protect the system form intruders. Hence, this work aims to create a new architecture, called “S-DRACA” (Secure, Dynamic and Distributed Role-based Access Control Architecture), which extends the work done with DACA so that it is capable of enforcing sequences of CRUD expressions that the applications can execute if the sequences are associated with their roles and the development of a security layer to make it secure. We discuss as well the performance of this system and its applicability to other environments outside of relational databases.Atualmente, aplicações que acedem a bases de dados utilizam ferramentas como o Java Database Connectivity, Hibernate ou ADO.NET para aceder aos dados nelas armazenados. Estas ferramentas estão desenhadas para unir os paradigmas das bases de dados relacionais e da programação orientada a objetos, mas não estão preocupados com as políticas de controlo de acesso a aplicar. Portanto, os programadores de aplicações têm de dominar as políticas estabelecidas a fim de desenvolver aplicações em conformidade com as políticas de controlo de acesso estabelecidas.. Além disso, existem situações em que as políticas de controlo de acesso podem evoluir dinamicamente. Nestes casos, torna-se difícil adequar os mecanismos de controlo de acesso. Este desafio motivou o desenvolvimento de uma extensão ao modelo de controlo de acesso baseado em papeis (RBAC) que define como permissões sequências de expressões para criar, ler, atualizar e apagar (CRUD) informação e as interfaces de acesso a cada uma delas. A partir destas permissões podem ser gerados artefactos de segurança do lado dos clientes, i.e. de uma forma distribuída, que lhes permitem aceder à informação armazenada na base de dados segundo as políticas definidas. Por cima desta extenção também foi criada uma camada de segurança para tornar o controlo de acesso seguro e obrigatório. Para a extensão do modelo RBAC este trabalho baseou-se num trabalho anterior que criou uma arquitectura dinâmica de controlo de acesso para aplicações de bases de dados relacionais, aqui referida como DACA (Dynamic Access Control Architecture). DACA utiliza informação da lógica de negócio e as políticas de controlo de acesso que foram definidos para criar dinamicamente os artefactos de segurança para as aplicações. Em situações onde as políticas de controle de acesso evoluem de forma dinâmica, os artefactos de segurança são ajustados automaticamente. Este trabalho base, no entanto, define como permissões as expressões CRUD, podendo estas ser executadas em qualquer ordem, e necessita de uma camada de segurança adequada para autenticar utilizadores e proteger os dados sensíveis de intrusos. Portanto, neste trabalho, pretende-se criar uma nova arquitectura, chamada “S-DRACA” (Secure, Dynamic and Distributed Role-based Access Control Architecture), que estende o trabalho feito no âmbito do DACA para que este seja capaz de garantir que sejam cumpridas sequência de expressões CRUD que as aplicações podem executar e que estão associados aos seus papéis nas políticas RBAC e desenvolver uma camada de segurança adequada para a tornar segura. Discutimos, também, o seu desempenho e aplicabilidade em outros ambientes sem ser em bases de dados relacionais

Secure Dynamic Cloud-based Collaboration with Hierarchical Access

In recent years, the Cloud has emerged as an attractive way of hosting and delivering services over the Internet. This has resulted in a renewed focus on information security in the case where data is stored in the virtual space of the cloud and is not physically accessible to the customer. Through this thesis the boundaries of securing data in a cloud context, while retaining the benefits of the cloud, are explored. The thesis addresses the increasing security concerns of migrating to the cloud andutilising it for data storage.The research of this thesis is divided into three separate areas: securing data in an untrusted cloud environment, ensuring data access control in the cloud, and securing data outside the cloud in the user's environment. Each area is addressed by separate conceptual designs. Together these comprise a secure dynamic cloud-based collaboration environment with hierarchical access. To further validate the conceptual designs, proof of concept prototypes have been constructed.The conceptual designs have been devised by exploring and extending the boundaries of existing secure data-storage schemes, and then combining these with well-known security principles and cutting-edge research within the field of cryptography. The results of this thesis are feasible conceptual designs for a cloud-based dynamic collaboration environment. The conceptual designs address the challenges of secure cloud-based storage and allow the benefits of cloud-based storage to be utilised. Furthermore, this thesis provides a solid foundation for further work within this field

From Conventional to State-of-the-Art IoT Access Control Models

open access articleThe advent in Online Social Networks (OSN) and Internet of Things (IoT) has created a new world of collaboration and communication between people and devices. The domain of internet of things uses billions of devices (ranging from tiny sensors to macro scale devices) that continuously produce and exchange huge amounts of data with people and applications. Similarly, more than a billion people are connected through social networking sites to collaborate and share their knowledge. The applications of IoT such as smart health, smart city, social networking, video surveillance and vehicular communication are quickly evolving people’s daily lives. These applications provide accurate, information-rich and personalized services to the users. However, providing personalized information comes at the cost of accessing private information of users such as their location, social relationship details, health information and daily activities. When the information is accessible online, there is always a chance that it can be used maliciously by unauthorized entities. Therefore, an effective access control mechanism must be employed to ensure the security and privacy of entities using OSN and IoT services. Access control refers to a process which can restrict user’s access to data and resources. It enforces access rules to grant authorized users an access to resources and prevent others. This survey examines the increasing literature on access control for traditional models in general, and for OSN and IoT in specific. Challenges and problems related to access control mechanisms are explored to facilitate the adoption of access control solutions in OSN and IoT scenarios. The survey provides a review of the requirements for access control enforcement, discusses several security issues in access control, and elaborates underlying principles and limitations of famous access control models. We evaluate the feasibility of current access control models for OSN and IoT and provide the future development direction of access control for the sam

Fine-grained access control framework for Igor, a unified access solution to the Internet of Things

With the growing popularity of the Internet of Things (IoT), devices in households and offices are becoming information sharing "smart" devices controlled via network connections. The growth of collection, handling and distribution of data generated by IoT devices presents ethical and privacy issues. Users have no control over what information is kept or revealed, the interpretation of data collected, data ownership and who can access specific information generated by their IoT devices. This paper describes an approach to data ethical/privacy issues related to IoT using a fine-grained access-control framework on Igor, a centralized home and office automation solution. We designed a capability-based access control framework on top of Igor that allows agents, either human or machine, to access and change only the data to which they are authorised. The applicability of this to the European General Data Protection Regulation (GDPR) should be obvious. The implementation, expert evaluation and performance measurement results demonstrate that this is a promising solution for securing access to data generated by IoT devices

Secure data sharing in cloud and IoT by leveraging attribute-based encryption and blockchain

“Data sharing is very important to enable different types of cloud and IoT-based services. For example, organizations migrate their data to the cloud and share it with employees and customers in order to enjoy better fault-tolerance, high-availability, and scalability offered by the cloud. Wearable devices such as smart watch share user’s activity, location, and health data (e.g., heart rate, ECG) with the service provider for smart analytic. However, data can be sensitive, and the cloud and IoT service providers cannot be fully trusted with maintaining the security, privacy, and confidentiality of the data. Hence, new schemes and protocols are required to enable secure data sharing in the cloud and IoT. This work outlines our research contribution towards secure data sharing in the cloud and IoT. For secure data sharing in the cloud, this work proposes several novel attribute-based encryption schemes. The core contributions to this end are efficient revocation, prevention of collusion attacks, and multi-group support. On the other hand, for secure data sharing in IoT, a permissioned blockchain-based access control system has been proposed. The system can be used to enforce fine-grained access control on IoT data where the access control decision is made by the blockchain-based on the consensus of the participating nodes”--Abstract, page iv