Security Enhanced Anonymous User Authenticated Key Agreement Scheme Using Smart Card

Nowadays, the password-based remote user authentication mechanism using smart card is one of the simplest and convenient authentication ways to ensure secure communications over the public network environments. Recently, Liu et al. proposed an efficient and secure smart card based password authentication scheme. However, we find that Liu et al.’s scheme is vulnerable to the off-line password guessing attack and user impersonation attack. Furthermore, it also cannot provide user anonymity. In this paper, we cryptanalyze Liu et al.’s scheme and propose a security enhanced user authentication scheme to overcome the aforementioned problems. Especially, in order to preserve the user anonymity and prevent the guessing attack, we use the dynamic identity technique. The analysis shows that the proposed scheme is more secure and efficient than other related authentication schemes.

HARQ Optimization for PDCP Duplication-Based 5G URLLC Dual Connectivity

Packet duplication(PD)with dual connectivity(DC)was newly introduced in the 5G New Radio(NR)specifications to meet the stringent ultra reliable low latency communication(URLLC)requirements.PD technology uses duplicated packets in the packet data convergence protocol(PDCP)layer that are transmitted via two different access nodes(ANs)to the user equipment(UE)in order to enhance the reliability performance.However,PD can result in unnecessary retransmissions in the lower layers since the hybrid automatic retransmission request(HARQ)operation is unaware of the transmission success achieved through the alternate DC link to the UE.To overcome this issue,in this paper,a novel duplication-aware retransmission optimization(DRO)scheme is proposed to reduce the resource usage induced by unnecessary HARQ retransmissions.The proposed DRO scheme can minimize the average channel use while satisfying the URLLC requirements.The proposed DRO scheme derives the optimal HARQ retransmission attempts for different ANs by solving a nonlinear integer programming(NLIP)problem.The performance of the proposed DRO scheme was evaluated using MATLAB simulation and is compared to the existing 5G HARQ support schemes.The simulations results show that the proposed DRO scheme can provide a 14.71%and 15.11%reduced average channel use gain compared to the selective data duplication upon failure(SDUF)scheme and latency-aware dynamic multi-connectivity algorithm(LADMA)scheme,respectively,which are the existing 5G PD schemes that use HARQ.

Analysis of Wireless Backhaul Networks Based on Aerial Platform Technology for 6G Systems

As next generation communication technologies emerge,new high data rate applications and high-definition large-screen video streaming have become very popular.As a result,network traffic has been increasing so much that existing backhaul networks soon will not be able to support all traffic demands.To support these needs in future 6G mobile systems,the establishment of an additional backhaul wireless network is considered essential.As one of the solutions,a wireless backhaul network based on an aerial platform has been proposed.In order to explore the potential of aerial platforms as wireless backhaul networks,in this paper,the categories for wireless backhaul networks based on aerial platforms are investigated.This paper includes a survey of the definitions and characteristics of low altitude platforms(LAPs)and high altitude platforms(HAPs),as well as channel models according to the atmosphere.For wireless backhaul network designs based on aerial platforms,altitude and platform selection options,deployment options,energy issues,and security based on target location and performance were considered in the analysis and investigation.