Search

The dynamic charging system of electric vehicles has great potential for development. Electric vehicles initiate charging requests, and charging stations charge authorized electric vehicles. Fog computing improves the efficiency of request processing. However, open channels can be vulnerable to various attacks by a malicious adversary. Mutual authentication schemes allow users and charging stations to confirm each other. Therefore, numerous authentication and key agreement schemes have been proposed. In 2021, Babu et al. proposed an authentication scheme based on fog servers. Unfortunately, we found that their scheme can not resist FS impersonation attack and replay attack. Hence, we propose an authentication scheme between electric vehicles and fog servers to resolve the security weakness. Our scheme uses lightweight hash functions and XOR operations, which is more suitable for resource‐constrained electric vehicles. We proved our scheme can achieve mutual authentication by using BAN logic, and analyzed that our scheme can resist impersonation, replay, and known session key attacks, ensuring anonymity and untraceability. We finally compare computation cost and communication cost of our scheme with the existing schemes. The result shows that our scheme performs better than others overall. Therefore, our scheme is secure and suitable for dynamic charging systems. [ABSTRACT FROM AUTHOR]

Recently, many organic optoelectronic materials (OOMs), especially those used in organic light-emitting diodes (OLEDs), organic solar cells (OSCs), and organic field-effect transistors (OFETs), are explored for biomedical applications including imaging and photoexcited therapies. In this review, recently developed OOMs for fluorescence imaging, photoacoustic imaging, photothermal therapy, and photodynamic therapy, are summarized. Relationships between their molecular structures, nanoaggregation structures, photophysical mechanisms, and properties for various biomedical applications are discussed. Mainly four kinds of OOMs are covered: thermally activated delayed fluorescence materials in OLEDs, conjugated small molecules and polymers in OSCs, and charge-transfer complexes in OFETs. Based on the OOMs unique optical properties, including excitation light wavelength and exciton dynamics, they are respectively exploited for suitable biomedical applications. This review is intended to serve as a bridge between researchers in the area of organic optoelectronic devices and those in the area of biomedical applications. Moreover, it provides guidance for selecting or modifying OOMs for high-performance biomedical uses. Current challenges and future perspectives of OOMs are also discussed with the hope of inspiring further development of OOMs for efficient biomedical applications., (© 2023 Wiley‐VCH GmbH.)