Connected vehicle means providing different services, such as advanced driver-assistance systems (ADAS) from vehicles connected to the network. Vehicular ad-hoc networks (VANETs) can support vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications to realize connected vehicle. In VANETs, secure communication must be ensured, as otherwise it can lead to traffic accidents and human injuries. Recently, many studies on V2I authentication have been conducted to guarantee the security of V2I communications. However, recent V2I authentication protocols do not consider the handover situation, and it causes unnecessary computations. As vehicles have limited computing resources, unnecessary computation can lead to overload to the vehicles. In recent years, blockchain-based VANET is an active field of research because it can provide decentralization, data integrity and transparency. Using the strength of the blockchain technology, we design a blockchain-based handover authentication protocol for VANETs. In the proposed protocol, vehicles only perform lightweight computations in handover situations for efficiency of the network. We also conduct the formal analysis such as Burrows–Abadi–Needham (BAN) logic, Real-Or-Random (ROR) oracle model, and Automated Validation of Internet Security Protocols and Applications (AVISPA) simulation to the proposed protocol. We simulate the proposed protocol using network simulator 3 (NS-3) to verify that the proposed protocol is practical. Finally, we compare the computational cost and security features of the proposed protocol with existing protocols to show that the proposed protocol is more secure and efficient.

During the COVID-19 pandemic, engagement in various remote activities such as online education and meetings has increased. However, since the conventional online environments typically provide simple streaming services using cameras and microphones, there have limitations in terms of physical expression and experiencing real-world activities such as cultural and economic activities. Recently, metaverse environments, three-dimensional virtual reality that use avatars, have attracted increasing attention as a means to solve these problems. Thus, many metaverse platforms such as Roblox, Minecraft, and Fortnite have been emerging to provide various services to users. However, such metaverse environments are potentially vulnerable to various security threats because the users and platform servers communicate through public channels. In addition, sensitive user data such as identity, password, and biometric information are managed by each platform server. In this paper, we design a system model that can guarantee secure communication and transparently manage user identification data in metaverse environments using blockchain technology. We also propose a mutual authentication scheme using biometric information and Elliptic Curve Cryptography (ECC) to provide secure communication between users and platform servers and secure avatar interactions between avatars and avatars. To demonstrate the security of the proposed mutual authentication scheme, we perform informal security analysis, Burrows–Abadi–Needham (BAN) logic, Real-or-Random (ROR) model, and Automated Validation of Internet Security Protocols and Applications (AVISPA). In addition, we compare the computation costs, communication costs, and security features of the proposed scheme with existing schemes in similar environments. The results demonstrate that the proposed scheme has lower computation and communication costs and can provide a wider range of security features than existing schemes. Thus, our proposed scheme can be used to provide secure metaverse environments.

Telecare medical information system (TMIS) implemented in wireless body area network (WBAN) is convenient and time-saving for patients and doctors. TMIS is realized using wearable devices worn by a patient, and wearable devices generate patient health data and transmit them to a server through a public channel. Unfortunately, a malicious attacker can attempt performing various attacks through such a channel. Therefore, establishing a secure authentication process between a patient and a server is essential. Moreover, wearable devices have limited storage power. Cloud computing can be considered to resolve this problem by providing a storage service in the TMIS environment. In this environment, access control of the patient health data is essential for the quality of healthcare. Furthermore, the database of the cloud server is a major target for an attacker. The attacker can try to modify, forge, or delete the stored data. To resolve these problems, we propose a secure authentication protocol for a cloud-assisted TMIS with access control using blockchain. We employ ciphertext-policy attribute-based encryption (CP-ABE) to establish access control for health data stored in the cloud server, and apply blockchain to guarantee data integrity. To prove robustness of the proposed protocol, we conduct informal analysis and Burrows-Adabi-Needham (BAN) logic analysis, and we formally validate the proposed protocol using automated validation of internet security protocols and applications (AVISPA). Consequently, we show that the proposed protocol provides more security and has better efficiency compared to related protocols. Therefore, the proposed protocol is proper for a practical TMIS environment.

In the recent COVID-19 situation, Telecare Medical Information System (TMIS) is attracting attention. TMIS is one of the technologies used in Wireless Body Area Network (WBAN) and can provide patients with a variety of remote healthcare services. In TMIS environments, sensitive data of patients are communicated via an open channel. An adversary may attempt various security attacks including impersonation, replay, and forgery attacks. Therefore, numberous authentication schemes have been suggested to provide secure communication for TMIS. Sahoo et al. proposed a mutual authentication scheme based on biometrics and Elliptic Curve Cryptography (ECC) in 2020. However, we find out that Sahoo et al. ’s scheme cannot resist insider and privileged insider attacks and cannot guarantee patient anonymity. In this paper, we propose a secure ECC-based three-factor mutual authentication protocol that guarantees the privacy of patients for TMIS. We conduct informal security analysis to prove that our protocol is secure from various security attacks. In addition, we perform formal security analyses using the Automated Validation of Internet Security Protocols and Applications (AVISPA), Burrows-Abadi-Needham (BAN) logic, and the Real-Or-Random (ROR) model. Furthermore, we assess our protocol’s performance and compare it to other protocols. As a result, our protocol has lower communication costs, and better security features compared to related existing protocols. Therefore, our protocol is more appropriate for TMIS environments than other related protocols.

Digital twin technology is recently in the spotlight because of its potential applicability in business and industry. In digital twin environments, data generated from physical assets are transmitted to a remote server, which performs simulations through digital twins in a virtual space. Then, the simulation results can be shared with the data owner or other users. However, several challenges exist in the application of digital twin technology in the real world. One of the main challenges involves determining how to share real-time data for the simulation and how to share the simulation data securely. The data generated from physical assets may include sensitive information from data owners, and the leakage of data to an adversary can cause serious privacy problems. Moreover, the sharing of data with other data users should also be considered to maximize the availability of digital twin data. To resolve these issues, we propose a system model for the secure sharing of digital twin data. The proposed system model uses cloud computing for efficient data sharing and blockchain for data verifiability. We also propose communication schemes for the proposed model to guarantee privacy preservation and data security in wireless channels. We analyze the security of the proposed protocol using informal methods and formal methods such as BAN logic and the AVISPA simulation tool. Furthermore, we compare the proposed protocol with related protocols and demonstrate that the proposed scheme is applicable to digital twin environments.

With the information and communication technologies (ICT) and Internet of Things (IoT) gradually advancing, smart homes have been able to provide home services to users. The user can enjoy a high level of comfort and improve his quality of life by using home services provided by smart devices. However, the smart home has security and privacy problems, since the user and smart devices communicate through an insecure channel. Therefore, a secure authentication protocol should be established between the user and smart devices. In 2020, Xiang and Zheng presented a situation-aware protocol for device authentication in smart grid-enabled smart home environments. However, we demonstrate that their protocol can suffer from stolen smart device, impersonation, and session key disclosure attacks and fails to provide secure mutual authentication. Therefore, we propose a secure and lightweight authentication protocol for IoT-based smart homes to resolve the security flaws of Xiang and Zheng’s protocol. We proved the security of the proposed protocol by performing informal and formal security analyses, using the real or random (ROR) model, Burrows–Abadi–Needham (BAN) logic, and the Automated Validation of Internet Security Protocols and Applications (AVISPA) tool. Moreover, we provide a comparison of performance and security properties between the proposed protocol and related existing protocols. We demonstrate that the proposed protocol ensures better security and lower computational costs than related protocols, and is suitable for practical IoT-based smart home environments.