Formalizing and Conformance Testing ABAC Policies in Process Logs via an ABAC Metamodel

In this disseration we propose semi-automated top-down policy engineering approaches for attribute-based access control (ABAC) development. Further, we propose a hybrid ABAC policy engineering approach to combine the benefits and address the shortcomings of both top-down and bottom-up approaches. In particular, we propose three frameworks: (i) ABAC attributes extraction, (ii) ABAC constraints extraction, and (iii) hybrid ABAC policy engineering. Attributes extraction framework comprises of five modules that operate together to extract attributes values from natural language access control policies (NLACPs); map the extracted values to attribute keys; and assign each key-value pair to an appropriate entity. For ABAC constraints extraction framework, we design a two-phase process to extract ABAC constraints from NLACPs. The process begins with the identification phase which focuses on identifying the right boundary of constraint expressions. Next is the normalization phase, that aims at extracting the actual elements that pose a constraint. On the other hand, our hybrid ABAC policy engineering framework consists of 5 modules. This framework combines top-down and bottom-up policy engineering techniques to overcome the shortcomings of both approaches and to generate policies that are more intuitive and relevant to actual organization policies. With this, we believe that our work takes essential steps towards a semi-automated ABAC policy development experience.

We describe a method that centrally manages Attribute-Based Access Control (ABAC) policies and locally computes and enforces decisions regarding those policies for protection of resource repositories in host systems using their native Access Control List (ACL) mechanisms. The method is founded on the expression of an ABAC policy that conforms to the access control rules of an enterprise and leverages the ABAC policy expression by introducing representations of local host repositories into the ABAC policy expression as objects or object attributes. Repositories may be comprised of individual files, directories, or other resources that require protection. The method further maintains a correspondence between the ABAC representations and repositories in local host systems. The method also leverages an ability to conduct policy analytics in such a way as to formulate ACLs for those representations in accordance with the ABAC policy and create ACLs on repositories using the ACLs of their corresponding representations. As the ABAC policy configuration changes, the method updates the ACLs on affected representations and automatically updates corresponding ACLs on local repositories. Operationally, users attempt to access resources in local host systems, and the ABAC policy is enforced in those systems in terms of their native ACLs.

Chapter 23 - Policies, Access Control, and Formal Methods

Access control policies are dynamic in nature, and therefore require frequent updates to synchronize with the latest organizational security requirements. As these updates are handled, it is important that all user access requests be answered contemporaneously and correctly without any interruption or delay. In this paper, considering the context of Attribute Based Access Control (ABAC), we propose an approach that is capable of immediately materializing any update to the policy and ensuring that it is taken into account for any subsequent access requests. One possibility is to update the policy based on the incoming changes through ABAC policy mining techniques. However, it turns out that no existing mining approach can offer correct enforcement of policies when access requests are entertained during the updates. We provide a formal proof for this surprising result and then propose an approach called δwOP that does not suffer from this problem. Essentially, δwOP keeps track of the needed information from updates and uses this in conjunction with the existing ABAC policy rules to make access decisions. We present the complexity analysis as well as a comprehensive experimental evaluation to demonstrate the efficacy of the proposed approach for different types of changes.

[formula omitted]: A blockchain-based secure access control management for the Internet of Things

A Virtual Organization (VO) consists of some real organizations with common interests, which aims to provide inter organizational associations to reach some common goals by sharing their resources with each other. Providing security mechanisms, and especially a suitable access control mechanism, which enforces the defined security policy is a necessary requirement in VOs. Since VO is a complex environment with the huge number of users and resources, traditional access control models cannot satisfy VOs security requirements. Most of the current proposals are basically based on the attributes of users and resources. In this paper, we suggest using a combination of the semantic based access control (SBAC) model, and the attribute based access control (ABAC) model with the shared ontology of subjects' attributes in VOs. In this model, each participating organization makes its access control decisions according to an enhanced model of the ABAC model. However, access decision in the VO is made in more abstract level through an enhanced model of theSBACmodel. Using the ontology of users and resources in this model facilitates access control in large scale VOs with numerous organizations. By the combination ofSBACand ABAC, we attain their benefits and eliminate their shortcomings. In order to show the applicability of the proposed model, an access control system, based on the proposed model, has been implemented in Java using available APIs, including Sun's XACML API, Jena, Pellet, and Protege.

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.

Proliferation of smart, connected devices brings new challenges to data access and privacy control. Fine grained access control policies are typically complex, hard to maintain and tightly bound to the internal structure of the processed information. We thus discuss how semantic inference can be used together with an intuitive ontology management tool to ease the management of Attribute Based Access Control policies, even by users not experienced with semantic technologies.

In big data environments with big number of users and high volume of data, we need to manage the corresponding huge number of security policies. Using Attribute-Based Access Control (ABAC) model to ensure access control might become complex and hard to manage. Moreover, ABAC policies may be aggregat

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 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.

Attribute-Based Access Control (ABAC) is increasingly becoming popular due to its dynamic, flexible, portable, and scalable nature. Under ABAC, security policies (ABAC rules) are stated in terms of the attributes of the subject, the object and the environment. A subject is granted access to an object if their respective attribute values are satisfied against a set of ABAC rules. Typically hierarchical relationships exist among the subjects as well as the objects, where more specific subjects (objects) inherit the attributes from the general ones. As such, if a subject is allowed access to a general object, that subject is allowed to access all of its sub-types. This has been the general understanding and current ABAC enforcement and policy mining approaches follow this approach. However, in this article, we argue that the general understanding of the semantics of the ABAC is not always appropriate. Indeed, under certain semantics, the specific data may be more sensitive than that of its general counterpart. In that situation, if a subject is allowed access to a general type, it should not be allowed access to its sub-type, which is contrary to the current understanding and implementation. This paper is the first attempt in the literature to distinguish these two different ABAC semantics arising from the different semantics of object attributes themselves. We present concrete examples of these two semantics and demonstrate what can go wrong - both anecdotally as well as empirically - if one ignores the underlying semantics and inappropriately uses the existing enforcement and mining algorithms. We then present how existing algorithms can be modified so that no misconfigurations arise and security is ensured.

Nowadays, cloud-based storage systems play a vital role in IoT data storage, processing, and sharing. Despite its contribution, the current cloud-based architecture may cause severe data leakage or jeopardize user privacy. Meanwhile, the cloud-based architecture heavily relies on a trusted third-party auditor (TPA) and runs in a centralized control manner. However, the TPA may not be a completely trustworthy entity, and a single point of failure might cause the centralized system to collapse. Fortunately, with the advent of blockchain technology, the decentralized storage model has gained popularity. A decentralized storage system successfully eradicates the rule of TPA, solves the problem of a single point of failure, and has many advantages over a centralized control architecture, such as low storage prices and high throughput. This study offers a blockchain-based decentralized distributed storage and sharing scheme that provides end-to-end encryption and fine-grained access control. In our proposed IoTChain model, fine-grained permission is based on attribute-based access control (A-BAC) policy by employing the Ethereum blockchain as an auditable access control layer. Smart contracts are tailored for the IoTChain model, which combines the Ethereum blockchain and the interplanetary file system (IPFS). We used an advanced encryption standard (AES) for encryption and the elliptic curve Diffie-Hellman key exchange protocol for secret key sharing between data owners and users. Also, the proof-of-work (PoW) consensus mechanism is replaced with a proof-of-authority (PoA) to minimize system transaction cost and boost system throughput. Additionally, our solution has been tested on the Ethereum official test network Rinkeby, and the results demonstrate that our approach is realistic and economical on the IoT data.

Role based access control (RBAC) is well known due to its high security and ease in management for permissions. But it also has some deficiencies like role structure complexity and having no dynamic behavior. Attribute based access control (ABAC) is a dynamic access control model that provides ease of role structuring. Analyzing roles and permissions after implementing access control model and its management is not easy in ABAC. In this paper, an access control model is developed that accumulates the strengths of RBAC and ABAC and also remove some of the deficiencies of above stated models. The proposed model implements and exploits the attributes of objects, permissions, roles, and users as foundation. Moreover the proposed model employs the role structuring ability of ABAC and tight security behavior of RBAC. We also implemented the proposed model and discussed with respect to a case study.

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.