In pursuit of effective service level agreement (SLA) monitoring and enforcement in the context of Internet of Things (IoT) applications, this article regards SLA management as a distrusted process that should not be handled by a single authority. Here, we aim to justify our view on the matter and propose a conceptual blockchain-based framework to cope with some limitations associated with traditional SLA management approaches.

A Service Level Agreement (SLA) establishes the trustworthiness of service providers and consumers in several domains; including the Internet of Things (IoT). Given the proliferation of Blockchain technology, we find it compelling to reconsider the assumption of trust and centralised governance typically practised in SLA management including monitoring, compliance assessment, and penalty enforcement. Therefore, we argue that, such critical tasks should be operated by blockchain-based smart contracts in a non-repudiable manner beyond the influence of any SLA party. This paper envisions an IoT scenario wherein a firefighting station outsources end-to-end IoT operations to a specialised service provider. The contractual relationship between them is governed by an SLA which stipulates a set of quality requirements and violation consequences. The main contribution of this paper lies in designing, deploying and empirically experimenting a novel blockchain-based SLA monitoring and compliance assessment framework in the context of IoT. This is done by utilising Hyperledger Fabric (HLF), an enterprise-grade blockchain technology. Our work highlights a set of considerations and best practice at two sides, the IoT application monitoring-side and the blockchain-side. Moreover, it experimentally validates the reliability of the proposed monitoring approach, which collects relevant metrics from each IoT component and examines them against the quality requirements stated in the SLA. Finally, we propose a novel design for smart contracts at the blockchain-side, analyse and benchmark the performance, and demonstrate that the new design proves to successfully handle Multiversion Concurrency Control (MVCC) conflicts typically encountered in blockchain applications, while maintaining sound throughput and latency.

Cloud services provided by Microsoft are growing rapidly in number and importance. Azure Active Directory (AAD) is becoming more important due to its role in facilitating identity management for cloud-based services. However, several risks and security issues have been associated with cloud systems due to vulnerabilities associated with identity management systems. In particular, misconfigurations could severely impact the security of cloud-based systems. Accordingly, this study identifies and experimentally evaluates exploitable misconfiguration vulnerabilities in Azure AD which can eventually lead to the risk of privilege escalation attacks. The study focuses on two scenarios: dynamic group settings and the activation of the Managed Identity feature on virtual devices. Through experimental evaluation, the research demonstrates the successful execution of these attacks, resulting in unauthorized access to sensitive information. Finally, we suggest several approaches to prevent such attacks by isolating sensitive systems to minimize the possibility of damage resulting from a misconfiguration accident and highlight the need for further studies.

Recently, the Internet of Things (IoT) environment has become increasingly fertile for malicious users to break the security and privacy of IoT users. Access control is a paramount necessity to forestall illicit access. Traditional access control mechanisms are designed and managed in a centralized manner, thus rendering them unfit for decentralized IoT systems. To address the distributed IoT environment, blockchain is viewed as a promising decentralised data management technology. In this thesis, we investigate the state-of-art works in the domain of distributed blockchain-based access control. We establish the most important requirements and assess related works against them. We propose a Distributed Blockchain and Attribute-based Access Control model for IoT entitled (DBC-ABAC) that merges blockchain technology with the attribute-based access control model. A proof-of-concept implementation is presented using Hyperledger Fabric. To validate performance, we experimentally evaluate and compare our work with other recent works using Hyperledger Caliper tool. Results indicate that the proposed model surpasses other works in terms of latency and throughput with considerable efficiency.