An Immunity Passport Scheme Based on the Dual-Blockchain Architecture for International Travel

The implementation of immunity passport has been hampered by the controversies over vaccines in various countries, the privacy of vaccinators, and the forgery of passports. While some existing schemes have been devoted to accelerating this effort, the problems above are not well solved in existing schemes. In this paper, we present an immunity passport scheme based on the dual-blockchain architecture, which frees people from the cumbersome epidemic prevention process while traveling abroad. Specially, the dual-blockchain architecture is established to fit with the scenarios of immunity passport. Searchable encryption and anonymous authentication are utilized to ensure users’ privacy. In addition, the performance and security evaluations show that our scheme achieves the proposed security goals and surpasses other authentication schemes in communicational and computational overheads.

A Secure and Privacy-Preserving Three-Factor Anonymous Authentication Scheme for Wireless Sensor Networks in Internet of Things

The Internet of things is playing more and more important role in smart healthcare, smart grids, and smart transportation, and using wireless sensor network (WSN), we can easily obtain and transmit information. However, the data security and users’ privacy are the biggest challenges for WSN because sensor nodes have low computing power and low storage capacity and are easy to be captured, and wireless networks are vulnerable. In 2021, Shuai et al. proposed a lightweight three-factor anonymous authentication scheme for WSN. However, we found that their protocol is vulnerable to stolen-verifier attack, modification of messages’ attack, and no perfect forward secrecy. Then, a new three-factor anonymous authentication scheme using elliptic curve cryptography (ECC) is proposed. Through informal and formal security analyses, our scheme can resist various known attacks and maintains low computational complexity.

An improved efficient anonymous authentication with conditional privacy-preserving scheme for VANETs

The study of security and privacy in vehicular ad hoc networks (VANETs) has become a hot topic that is wide open to discussion. As the quintessence of this aspect, authentication schemes deployed in VANETs play a substantial role in providing secure communication among vehicles and the surrounding infrastructures. Many researchers have proposed a variety of schemes related to information verification and computation efficiency in VANETs. In 2018, Kazemi et al. proposed an evaluation and improvement work towards Azees et al.’s efficient anonymous authentication with conditional privacy-preserving (EAAP) scheme for VANETs. They claimed that the EAAP suffered from replaying attacks, impersonation attacks, modification attacks, and cannot provide unlinkability. However, we also found out if Kazemi et al.’s scheme suffered from the unlinkability issue that leads to a forgery attack. An adversary can link two or more messages sent by the same user by applying Euclid’s algorithm and derives the user’s authentication key. To remedy the issue, in this paper, we proposed an improvement by encrypting the message using a shared secret key between sender and receiver and apply a Nonce in the final message to guarantee the unlinkability between disseminated messages.

How to Design a Secure Anonymous Authentication and Key Agreement Protocol for Multi-Server Environments and Prove Its Security

An anonymous authentication and key agreement (AAKA) protocol provides anonymous members symmetric authentication and establishes a symmetric session key for secure communication in public networks. Today, numerous popular remote services are based on multi-server architecture, such as the internet of things (IoT), smart cities, cloud services, vehicular ad hoc networks (VANET), and telecare medicine information systems (TMIS). Many researchers have attempted to design AAKA protocols in multi-server environments for various applications. However, many of these have security defects, even if they have so-called “formal” security proofs. In this paper, we analyze related AAKA protocols to identify the common design defects, expound the process of designing secure AAKA protocols, and explain why the present AAKA protocols still suffer attacks, despite having security proofs. We instruct readers on how to design a secure AAKA protocol and how to prove the security. This paper will therefore be helpful for the design of new AAKA protocols, and for ensuring their security.