Xidian University

About: Xidian University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Antenna (radio) & Synthetic aperture radar. The organization has 32099 authors who have published 38961 publications receiving 431820 citations. The organization is also known as: University of Electronic Science and Technology at Xi'an & Xīān Diànzǐ Kējì Dàxué.

Privacy-Oriented Blockchain-Based Distributed Key Management Architecture for Hierarchical Access Control in the IoT Scenario

Abstract: The rapid development of the Internet of Things (IoT) and the explosive growth of valuable data produced by user equipment have led to strong demand for access control, especially hierarchical access control, which is performed from a group communication perspective. However, the key management strategies for such a future Internet are based mostly on a trusted third party that requires full trust of the key generation center (KGC) or central authority (CA). Recent studies indicate that centralized cloud centers will be unlikely to deliver satisfactory services to customers because we place too much trust in third parties; therefore, these centers do not apply to user privacy-oriented scenarios. This paper addresses these issues by proposing a novel blockchain-based distributed key management architecture (BDKMA) with fog computing to reduce latency and multiblockchains operated in the cloud to achieve cross-domain access. The proposed scheme utilizes blockchain technology to satisfy the decentralization, fine-grained auditability, high scalability, and extensibility requirements, as well as the privacy-preserving principles for hierarchical access control in IoT. We designed system operations methods and introduced different authorization assignment modes and group access patterns to reinforce the extensibility. We evaluated the performance of our proposed architecture and compared it with existing models using various performance measures. The simulation results show that the multiblockchain structure substantially improves system performance, and the scalability is excellent as the network size increases. Furthermore, dynamic transaction collection time adjustment enables the performance and system capacity to be optimized for various environments.

Identity verification in quantum key distribution

Abstract: The security of the previous quantum key distribution protocols, which is guaranteed by the laws of quantum physics, is based on legitimate users. However, impersonation of the legitimate communicators by eavesdroppers, in practice, will be inevitable. In this paper, we proposed a quantum key verification scheme, which can simultaneously distribute the quantum secret key and verify the communicators' identity. Investigation shows that this proposed identity verification scheme is secure.

A Compact Ultrawideband MIMO Antenna Using QSCA for High Isolation

Abstract: In this letter, a compact ultrawideband (UWB) multiple-input-multiple-output (MIMO) antenna with lower wireless local area network (WLAN) coverage is proposed. The proposed MIMO antenna consists of two quasi-self-complementary monopoles, which are easy to achieve ultrawideband operation. By arranging two monopoles symmetrically, with their main radiation directions oppositely oriented, a UWB MIMO antenna with high isolation is proposed. This high isolation is achieved without using any other decoupling methods, which, totally, benefits from the monopoles' complementary and asymmetrical structures. The measured |S11| has the band of mainly covering 2.19-11.07 GHz except a little higher than -10 dB at 2.86-3.28 GHz, and with |S21| ≤ - 20 dB at most of the band. Since the proposed monopole has excellent inherent properties, a four-element UWB MIMO antenna with good isolation is also discussed.

New Perspectives on Future Smart FiWi Networks: Scalability, Reliability, and Energy Efficiency

Abstract: Fiber-Wireless (FiWi) network, as an integration of optical fiber network and wireless access network, has attracted intensive research interest and enjoyed significant growth in its applications over the last two decades. Besides bringing great opportunities for the development of FiWi networks, the new applications and techniques, like the emerging Internet of Things (IoT), raise unprecedented challenges in different aspects of FiWi integration. Based on such observation, we provide in this paper a comprehensive survey of recent progress and ongoing research works in the aspects of network architecture, QoS provisioning, scalability improving, reliability enhancing, energy saving, as well as standardization activities and case studies. Furthermore, new trends and challenging issues on future smart FiWi networks are identified and discussed in details.