The Internet of Things (IoT) network is rapidly expanding due to sudden technological advancements, which enable objects to become intelligent and contribute to the network. Before permitting a newly added IoT device to communicate with the network, it is essential to provide access and authenticate the device’s legitimacy by ensuring that it has not been tampered. Recently, blockchain technology has been integrated into Attribute Based Access Control (ABAC) protocols to supply a more robust security mechanism for access control in IoT. The IoT and blockchain-based ABAC serve as the foundation of this survey, offering a comprehensive introduction to both topics. Additionally, several security concerns and vulnerabilities associated with Blockchain Envisioned ABAC (BE-ABAC) are presented. A Comparison with related surveys has also been made. Besides, we also present a comparative analysis based on evaluation based on Distance from Average Solution (EDAS) to rank the best schemes among the suggested BE-ABAC schemes. In conclusion, we discuss some open research challenges in an IoT network that uses blockchain to manage access control.

With the popularization and growing utilization of electronic health records (EHRs) coupled with the advancements in cloud computing, healthcare providers are interested in storing EHRs in third-party, semi-trusted cloud platforms. Given the collaborative nature of modern e-health environments, integrating access delegation is of paramount importance to strengthen the flexibility of the sharing of health information. However, access delegation has to be enforced in a controlled manner so that it will not jeopardize the security of the system. For such applications, attribute based encryption (ABE) mechanisms are quite useful given the fact that ABE facilitates an efficient way of enforcing secure, fine-grained access control over encrypted data. However, incorporating delegatability with ABE mechanisms is tricky, and the existing schemes lack the control over the process of delegation of encrypted data. As a solution, we propose a novel ABE based access control scheme which can enforce multi-level, controlled access delegation and demonstrated how it could be deployed in an e-health environment to securely share outsourced EHRs of patients. Furthermore, we have shown that the proposed scheme is secure against chosen plaintext attacks as well as attacks mounted via attribute collusion.

We propose an efficient anonymous, attribute-based credential scheme capable of provisioning multi-level credential delegations. It is integrated with a mechanism to revoke the anonymity of credentials for resolving access disputes and making users accountable for their actions. The proposed scheme has a lower end-user computational complexity in comparison to existing credential schemes with delegatability and has a comparable level of performance with the credential standards of U-Prove and Idemix. Furthermore, we demonstrate how the proposed scheme can be applied to a collaborative e-health environment to provide its users with the necessary anonymous access with delegation capabilities.

Personal health records (PHR) are an emerging health information exchange model, which facilitates PHR owners to efficiently manage their health data. Typically, PHRs are outsourced and stored in third-party cloud platforms. Although, outsourcing private health data to third-party platforms is an appealing solution for PHR owners, it may lead to significant privacy concerns, because there is a higher risk of leaking private data to unauthorized parties. As a way of ensuring PHR owners' control of their outsourced PHR data, attribute based encryption (ABE) mechanisms have been considered due to the fact that such schemes facilitate a mechanism of sharing encrypted data among a set of intended recipients. However, such existing PHR solutions suffer from inflexibility and scalability issues due to the limitations associated with the adopted ABE mechanisms. To address these issues, we propose a distributed multi-authority ABE scheme and thereby we show how a patient-centric, attribute based PHR sharing scheme which can provide flexible access for both professional users such as doctors as well as personal users such as family and friends is realized. We have shown that the proposed scheme supports on-demand user revocation as well as secure under standard security assumptions. In addition, the simulation results provide evidence for the fact that our scheme can function efficiently in practice. Furthermore, we have shown that the proposed scheme can cater the access requirements associated with distributed multiuser PHR sharing environments as well as more realistic and scalable compared with similar existing PHR sharing schemes.

Electronic health records (EHRs) play a vital role in modern health industry, allowing the possibility of flexible sharing of health information in the quest of provisioning advanced and efficient healthcare services for the users. Although sharing of EHRs has significant benefits, given that such records contain lot of sensitive information, secure sharing of EHRs is of paramount importance. Thus, there is a need for the realization of sophisticated access control mechanisms for secure sharing of EHRs, which has attracted significant interest from the research community. The most prominent access control schemes for sharing of EHRs found in literature are role based and such solutions have the drawback of requiring the users to be registered in the system. Therefore, we propose a secure attribute based EHR sharing scheme using selective disclosure of attributes, which can meet the security requirements of EHRs. The proposed model is policy based and the access decisions are made based on the possibility of a user for being able to provide a proof that the user possesses a set of attributes that satisfies the access policy referenced to the access requested resource. Furthermore, the proposed model is capable of granting access for registered users in the system as well as unregistered but legitimate users, paving the way towards realizing a secure and flexible EHR sharing scheme.