Semantically Rich, Context Aware Access Control for Openstack

In many domains, organizations must model personnel and corresponding data access privileges as fine-grained hierarchical access control models. One class of such models, Role-based Access Control (RBAC) models, has been widely accepted and deployed. However, RBAC models are often used without involving cryptographic keys nor considering confidentiality/privacy at the data level. How to design, implement and dynamically modify such a hierarchy, ensure user and data privacy and distribute and manage necessary cryptographic keys are issues of the utmost importance. One elegant solution for cryptography-based hierarchical access control combines the collusion-resistant and privacy-preserving Access Control Polynomial (ACP) and Atallah's Dynamic and Efficient Extended Key Management scheme. Such a model involves cryptographic keys used to encrypt data, can address confidentiality/privacy at the data level and can efficiently support dynamic changes to the RBAC access hierarchy. In this paper, we discuss several implementation challenges and propose solutions when deploying such a system including: data encryption and decryption, key storage and key distribution. Furthermore, we provide analysis of the efficiency and scalability of the resulting system.

A major development in the field of access control is the dominant role-based access control (RBAC) scheme. The fascination of RBAC lies in its enhanced security along with the concept of roles. In addition, attribute-based access control (ABAC) is added to the access control models, which is famous for its dynamic behavior. Separation of duty (SOD) is used for enforcing least privilege concept in RBAC and ABAC. Moreover, SOD is a powerful tool that is used to protect an organization from internal security attacks and threats. Different problems have been found in the implementation of SOD at the role level. This paper discusses that the implementation of SOD on the level of roles is not a good option. Therefore, this paper proposes a hybrid access control model to implement SOD on the basis of permissions. The first part of the proposed model is based on the addition of attributes with dynamic characteristics in the RBAC model, whereas the second part of the model implements the permission-based SOD in dynamic RBAC model. Moreover, in comparison with previous models, performance and feature analysis are performed to show the strength of dynamic RBAC model. This model improves the performance of the RBAC model in terms of time, dynamicity, and automatic permissions and roles assignment. At the same time, this model also reduces the administrator’s load and provides a flexible, dynamic, and secure access control model.

Chapter 23 - Policies, Access Control, and Formal Methods

Current access control mechanisms of the hospital information system can hardly identify the real access intention of system users. A relaxed access control increases the risk of compromise of patient privacy. To reduce unnecessary access of patient information by hospital staff, this paper proposes a knowledge-constrained role-based access control (KC-RBAC) model in which a variety of medical domain knowledge is considered in access control. Based on the proposed Purpose Tree and knowledge-involved algorithms, the model can dynamically define the boundary of access to the patient information according to the context, which helps to protect patient privacy by controlling access. Compared with the role-based access control model, KC-RBAC can effectively protect patient information according to the results of the experiments.

Smart homes are interconnected homes in which a wide variety of digital devices with limited resources communicate with multiple users and among themselves using multiple protocols. The deployment of resource-limited devices and the use of a wide range of technologies expand the attack surface and position the smart home as a target for many potential security threats. Access control is among the top security challenges in smart home IoT. Several access control models have been developed or adapted for IoT in general, with a few specifically designed for the smart home IoT domain. Most of these models are built on the role-based access control (RBAC) model or the attribute-based access control (ABAC) model. However, recently some researchers demonstrated that the need arises for a hybrid model combining ABAC and RBAC, thereby incorporating the benefits of both models to better meet IoT access control challenges in general and smart homes requirements in particular. In this paper, we used two approaches to develop two different hybrid models for smart home IoT. We followed a role-centric approach and an attribute-centric approach to develop HyBAC <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{RC}$</tex-math></inline-formula> and HyBAC <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{AC}$</tex-math></inline-formula> , respectively. We formally define these models and illustrate their features through a use case scenario demonstration. We further provide a proof-of-concept implementation for each model in Amazon Web Services (AWS) IoT platform. Finally, we conduct a theoretical comparison between the two models proposed in this paper in addition to the EGRBAC model (RBAC model for smart home IoT) and HABAC model (ABAC model for smart home IoT), which were previously developed to meet smart homes' challenges.

The increased complexity of modern access control (AC) systems stems partly from the need to support diverse and multiple administrative domains. Systems engineering is a key technology to manage this complexity since it is capable of assuring that an operational system will adhere to the initial conceptual design and defined requirements. Specifically, the verification stage of an AC system should be based on techniques that have a sound and mathematical underpinning. Working on this assumption, model checking techniques are applied for the verification of predefined system properties, and thus, conducting a security analysis of a system. In this paper, we propose the utilization of automated and error-free model checking techniques for the verification of security properties in multi-domain AC systems. Therefore, we propose a formal definition in temporal logic of four AC system properties regarding secure inter-operation with Role-Based Access Control (RBAC) policies in order to be verified by using model checking. For this purpose, we demonstrate the implementation of a tool chain for expressing RBAC security policies, reasoning on role hierarchies and properly feeding the model checking process. The proposed approach can be applied in any RBAC model to efficiently detect non-conformance between an AC system and its security specifications. As a proof of concept, we provide examples illustrating the verification of the defined secure inter-operation properties in multi-domain RBAC policies.

With the increasingly strict requirement for computer system security, access control models have become more complex. Existing models, such as discretionary access control (DAC) model, mandatory access control (MAC) model, role based access control (RBAC) model, and attribute based access control (ABAC) model, all have advantages and disadvantages regarding practicability and security. In addition, there is an inherent security risk in these access control models. The models merely control the access permission, but ignore the verification for the identity credibility of the entities involved in the access. With the proposal of trusted computing and the application of trusted platform, it is possible to implement, on stand-alone computers, the verification of identity credibility for the entities involved in the access. In this paper, we analyze the authorization and access decision policy of the RBAC model and the ABAC model. The characteristics of the trusted computing, which can ensure the identity credibility of the entities involved in the access, is also considered. Based on the above analysis, we establish a trusted computing based enhanced access control (TCBEAC) model, which can be deployed on stand-alone computers for common users.

Provision for delegation of access privileges lends access control systems flexibility and context-awareness. The topic of delegation did not exist in classical computing security, but – as IT systems got more distributed and complex – provision for delegation became a necessary access-control feature, and consequently much effort has been dedicated to extend conventional access control models with delegation capability. Many such efforts have pivoted around the well-known Role-based Access Control (RBAC) model, mainly for compatibility reasons, as RBAC had already been considered the de facto industry standard – even before the need for delegation arose in enterprise information systems. However, delegation is arguably more discretionary in nature rather than role-based; especially for healthcare informatics which is the application domain for our proposed delegation framework. In this paper, we present a discretionary framework for delegation of access rights from a delegator to a delegatee by implementing a delegation-token and various stages of its life cycle in tamper-resistant devices including smartcards. The proposed framework is designed and implemented using our eTRON cybersecurity architecture which advocates use of public key cryptographic protocols for secure entity authentication, data integrity and data confidentiality.

Role-based access control (RBAC) is a widely-used protocol to design and build an access control for providing the system security regarding authorization. Even though in the context of internet resources access, the authentication and access control are providing critical functionalities. In practice, the RBAC model has three perspectives such as Access Control, End User, and Administrator. An access control model must be built while giving highest priority to Access Control dimension. It means that the system must be secure regarding authorization. Thus, the system may be less useful for end-users and administrators. In this paper, we categorize that the basic motivation behind RBAC model is the easiest administration compared to tight authorization that becomes the reason for the evolution of RBAC model. Tight authorization creates many problems to make a system secure regarding authorization. Therefore, the true dimensions of RBAC model are identified in this study to change the mindset of researchers that RBAC is evolved for easier administration instead of tight access control. We propose a solution to incorporate the concept of roles for relaxed administration along with the permission-based access control. Moreover, we conclude that the dynamic separation of duty (DSD) should be implemented by permissions instead of roles in RBAC model.

Access control is an important protection mechanism for information system. Access control enforces subjects access restrictions to objects. Legitimate users should be allowed to access objects and illegitimate users should be detained from accessing objects. Access control between multi-user and multi-object is the key technique in security management of workflow management systems (WfMS), and the mechanism of the role-based authorization and access control is an effective way to solve the problem. This paper designs a set of practical constraint mechanism of role-based access control for WfMS. After introducing authorization constraint mechanism, a new model of role-based access control, RBACWF, is proposed. The role assignment algorithm, role-assign(tasknumber, pre_ass) , is also given as a key technique in this model. After this, an application example is given to explain the execution of the algorithm. Finally, a practical WfMS based on above designs is supplied. The practice in the system’s design and execution has proved that the authorization mechanism is flexible, the performance of the access security is improved greatly, and it also simplifies the task complexity of security administrator.

Several researches in recent years have pointed out that for the proper enforcement of privacy policies within enterprise data handling practices the privacy requirements should be captured in access control systems. In this paper, we extend the role-based access control (RBAC) model to capture privacy requirements of an organization. The proposed purpose-aware RBAC extension treats purpose as a central entity in RBAC. The model assigns permissions to roles based on purpose related to privacy policies. Furthermore, the use of purpose as a separate entity reduces the complexity of policy administration by avoiding complex rules and applying entity assignments, coherent with the idea followed by RBAC. Our model also supports conditions (constraints and obligations) with clear semantics for enforcement, and leverages hybrid hierarchies for roles and purposes for enforcing fine grained purpose and role based access control to ensure privacy protection.

The area of smart homes is one of the most popular for deploying smart connected devices. One of the most vulnerable aspects of smart homes is access control. Recent advances in IoT have led to several access control models being developed or adapted to IoT from other domains, with few specifically designed to meet the challenges of smart homes. Most of these models use role-based access control (RBAC) or attribute-based access control (ABAC) models. As of now, it is not clear what the advantages and disadvantages of ABAC over RBAC are in general, and in the context of smart-home IoT in particular. In this paper, we introduce HABACα, an attribute-based access control model for smart-home IoT. We formally define HABACα and demonstrate its features through two use-case scenarios and a proof-of-concept implementation. Furthermore, we present an analysis of HABACα as compared to the previously published EGRBAC (extended generalized role-based access control) model for smart-home IoT by first describing approaches for constructing HABACα specification from EGRBAC and vice versa in order to compare the theoretical expressiveness power of these models, and second, analyzing HABACα and EGRBAC models against standard criteria for access control models. Our findings suggest that a hybrid model that combines both HABACα and EGRBAC capabilities may be the most suitable for smart-home IoT, and probably more generally.

In the past five years there has been tremendous activity in role-based access control (RBAC) models. Consensus has been achieved on a standard core RBAC model that is in process of publication by the US National Institute of Standards and Technology (NIST). An early insight was that RBAC cannot be encompassed by a single model since RBAC concepts range from very simple to very sophisticated. Hence a family of models is more appropriate than a single model. The NIST model reflects this approach. In fact RBAC is an open-ended concept which can be extended in many different directions as new applications and systems arise. The consensus embodied in the NIST model is a substantial achievement. All the same it just a starting point. There are important aspects of RBAC models, such as administration of RBAC, on which consensus remains to be reached. Recent RBAC models have studied newer concepts such as delegation and personalization, which are not captured in the NIST model. Applications of RBAC in workflow management systems have been investigated by several researchers. Research on RBAC systems that cross organizational boundaries has also been initiated. Thus RBAC models remain a fertile area for future research. In this paper we discuss some of the directions which we feel are likely to result in practically useful enhancements to the current state of art in RBAC models.KeywordsAccess ControlAccess Control ModelRBAC ModelMandatory Access ControlSpringer LNCSThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The rapid growth of Internet of Things (IoT)-enabled smart home environments has amplified the need for robust, scalable, and context-aware access control mechanisms. Traditional Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC) models offer distinct advantages such as hierarchical simplicity and contextual granularity, respectively, yet exhibit critical limitations when deployed in isolation. To address these constraints, this study proposes and implements a discrete, hybrid RBAC–ABAC access control framework, engineered as a smart contract on the Binance Smart Chain (BSC), to ensure a secure, decentralized model for managing access to IoT resources. The framework leverages blockchain’s inherent strengths cryptographic integrity, immutable message digests, and tamper-resistant audit trails to reinforce data confidentiality and policy enforcement. Validated on a real-world testbed comprising ESP32-based IoT devices, a Raspberry Pi gateway, and a blockchain backend, the proposed system demonstrates enhanced resilience and trust. Quantitative evaluations benchmark the hybrid model against standalone RBAC and ABAC mechanisms across key metrics, including gas consumption, access latency, access decision accuracy, and scalability. The results indicate the hybrid model achieves superior accuracy (97.2%) and scalability (supporting 50 concurrent users and 30 devices), with moderate gas usage (15,000 gwei) and acceptable latency (1.8 seconds). Furthermore, the use of laser-secure transaction protocols and cryptographic primitives within the smart contract enhances the protection of access rights and resource interactions. This hybrid smart contract architecture not only bridges the gap between theoretical access control models and practical blockchain deployments but also sets a foundation for adaptive, secure, and decentralized policy enforcement in next-generation smart homes, particularly in resource-constrained environments.

CRBAC: Imposing multi-grained constraints on the RBAC model in the multi-application environment