The transition from patient-centered medical services to Health 5.0, which provides medical services to all customers using smart healthcare, has led to the use of the Internet of Things (IoT) for medical diagnosis and research based on the personal health records (PHR) of service users. However, PHR contain sensitive personal information, which can cause privacy issues. Additionally, as emergencies may occur in real medical environments, multi-authority delegation must be considered. Although various methods are being studied for data sharing, they often do not meet the necessary security requirements in a real PHR sharing environment. In this study, we propose a system that uses key aggregate searchable encryption (KASE) to satisfy security requirements and leverages blockchain and smart contracts to improve data integrity, data audit records, and transparency. We also propose a method that ensures the data subject rights of PHR data owners when delegating multiple rights using attribute tokens. We conduct formal and informal security analyses to verify the robustness of the proposed system against potential adversarial attacks. Finally, a performance evaluation is conducted to verify the effectiveness of the proposed scheme.

Unmanned Aerial Vehicle(UAV)-assisted mobile edge computing(MEC) ensures continuous MEC services by promptly restoring overloaded or disabled MEC infrastructure. Equipped with sufficient computing resources, UAVs deploy to areas needing MEC, such as task offloading and entertainment services. However, in areas with paralyzed edge nodes, vehicle users are unable to verify the legitimacy of UAVs as they cannot access to the trusted authority(TA). Furthermore, the integrity of UAV-assisted MEC environments can be compromised by malicious attackers, as all network participants rely on wireless communication for their interactions. Many authentication schemes have been proposed for UAV environments. However, these schemes encounter a problem of having to communicate through TA for authentication with vehicle users, which makes them difficult to apply to UAV-assisted MEC environments. Therefore, we propose a new broadcast authentication protocol, which can recover MEC services using MEC-equipped UAVs. The proposed protocol can provide UAVs and vehicle users with high reliability via a self-certified public-key cryptosystem, which can verify the legitimacy of the communication partner without the TA. Moreover, we guarantee the user privacy and preserve sensitive information using biohash technology. We verify the security robustness of the proposed protocol using various simulation tool, informal, and formal analyses. We also estimate the practical deployment of the proposed protocol using “Network Simulator-3”. Moreover, we estimate the computation and communication overheads and compare with other existing protocols. The results show that the proposed protocol is feasible and provides users with convenient and seamless intelligent transportation services in UAV-assisted MEC environments.

With the ongoing revolutionary growth of the industrial Internet of Things and smart grid networks, smart grid (SG) communication has been acknowledged as a next-generation network for intelligent and efficient electric power transmission. In SG networks, smart meters (SMs) generally send requests for electricity demand to service providers (SPs), which deal with the requests for efficient energy distribution. However, SGs experience many security issues with the deployed SMs and untrusted wireless communication. To tackle these security issues, we propose a privacy-preserving authentication scheme for demand response management in SGs, called BPPS. It can resist various attacks and achieve secure mutual authentication with key agreement; moreover, it provides integrity of demand-response data using blockchain. Moreover, we perform the informal and formal (mathematical) security analysis to confirm that BPPS is secure against various attacks and achieves session key security, respectively. Furthermore, we conduct the performance and simulation analysis for SGs using NS3 and Ethereum testnet. Consequently, BPPS provides high-level security and can be applied to actual SG networks.

With the rapid development of micro-electronics and Information and Communication Technology (ICT), users can utilize various service such as Internet of Things(IoT), smart-healthcare and smart-home using wearable devices. However, the sensitive information of user are revealed by attackers because the medical services are provided through open channel. Therefore, secure mutual authentication and key establishment are essential to provide secure services for legitimate users in Wireless Body Area Networks(WBAN). In 2019, Gupta et al. proposed a lightweight anonymous user authentication and key establishment scheme for wearable devices. We demonstrate that their scheme cannot withstand user impersonation, session key disclosure and wearable device stolen attacks. We also propose a secure and lightweight mutual authentication and key establishment scheme using wearable devices to resolve the security shortcomings of Gupta et al.'s scheme. The proposed scheme can be suitable to resource-limited environments.

With the development of internet of things (IoT) and communication technology, the sensors and embedded devices collect a large amount of data and handle it. However, IoT environment cannot efficiently treat the big data and is vulnerable to various attacks because IoT is comprised of resource limited devices and provides a service through a open channel. In 2018, Sharma and Kalra proposed a lightweight multi-factor authentication protocol for cloud-IoT environment to overcome this problems. We demonstrate that Sharma and Kalra's scheme is vulnerable to identity and password guessing, replay and session key disclosure attacks. We also propose a secure multifactor authentication protocol to resolve the security problems of Sharma and Kalra's scheme, and then we analyze the security using informal analysis and compare the performance with Sharma and Kalra's scheme. The proposed scheme can be applied to real cloud-IoT environment securely.