Currently, Unmanned Aerial Vehicles (UAV) groups can quickly build a multi-hop transmission network, which have been widely utilized in emergency communication scenarios to perform search and rescue, environmental monitoring, personnel positioning, rapid networking, etc. In such emergency rescue situations, strict demands on real-time communication, security, and minimal resource consumption become paramount. Higher requirements for security, bandwidth, and real-time performance necessitate a secure and lightweight data transmission protocol. Additionally, due to the lack of personnel supervision in these scenarios, the probability of malicious nodes increases. Therefore, it is essential to quickly and proximally block malicious nodes’ data to prevent it from affecting subsequent network propagation, and to accurately identify the malicious nodes. To address these issues, in this paper, we propose a traceable, lightweight, and secure data transmission protocol for UAV multi-hop networks in emergency rescue scenarios. The proposed protocol can verify the integrity of data transmitted by a large number of nodes in real time, detect erroneous transmissions, and trace malicious users. Experimental results show that our protocol consistently outperforms the comparison schemes in terms of computational overhead. Moreover, in scenarios involving smaller groups (m=5) and fewer hops (n=4), it exhibits significantly lower communication bandwidth overhead than the reference methods. Security analysis using BAN logic and the formal verification tool Scyther indicates that the proposed scheme meets security requirements. Additionally, comparative analysis results demonstrate that the proposed scheme is highly effective and outperforms other related schemes under the unique constraints of emergency rescue scenarios, where rapid, secure decision-making and data transmission are critical.

The E-band millimeter-wave (mm-wave), i.e., at the 71-76 GHz and 81-86 GHz frequency bands, has a potential of providing fiber-equivalent capacities in long-range wireless backhauls. Before designing and deploying such systems, we need to understand E-band long-range propagation properties and transmission performance based on a large number of experiments. In the paper, we report our recent experimental study of 72-74 GHz E-band transmissions over 52-km terrestrial links. Particularly, we focus on received signal strength and its variations, polarization properties, multipath effects and achievable rates. The results show that atmospheric conditions along the long-distance line-of-sight (LOS) path greatly affect E-band propagation. Atmospheric turbulence may cause severe signal fading, even when there is no rain. Despite that, channel depolarization is found to be relatively low, and no strong multipath is observed, which favors polarization multiplexing. Using below 1-GHz bandwidth, uncoded data rates can reach 3.6 Gbps in co-polarized single-input single-output (SISO) links. The experimental results are useful for E-band system design in long-range backhaul scenarios.

In the pursuit of autonomous driving and intelligent traffic management, the core goal of 5G Vehicle-to-Everything (V2X) communication is to enhance the safety and efficiency of transportation systems. Modern transportation networks have evolved into 3-D structures, including bridges and tunnels from traditional 2-D ones, which poses a challenge to fixed base stations-based networks reliant on supporting continuous and seamless coverage. Against this backdrop, unmanned aerial vehicles (UAVs) play a crucial role in developing multidimensional wireless networks due to their flexibility and functionality. This article proposes a UAV-assisted vehicle authentication (UAVA) scheme. It harnesses the efficiency of edge computing and the security of zero-trust architecture, focusing on enhancing the safety and efficiency of V2X communications. The UAVA scheme employs Chebyshev chaotic mapping and elliptic curve cryptography to strengthen communication security, adapting to the dynamic interactions between vehicles and UAVs. We validate the security using BAN logic and the Scyther tool and assess performance through experiments in a real hardware environment. The results indicate that UAVA offers higher security and lower communication overhead in serverless scenarios compared to existing solutions. These comprehensive evaluations show the potential of UAVA for application in intelligent transportation systems, especially in ensuring secure communications.

Presently, the prevalent authentication approaches in smartphones are susceptible to interference from light, noise, temperature, and the risk of replay attacks. In the light of these vulnerabilities, and taking into account user behavior alongside smartphone interaction patterns, we have developed an innovative behavioral-based authentication system. This system harnesses the distinctiveness of individual keystroke dynamics for secure user authentication, offering resilience against noise and light fluctuations. In this unique approach, our smartphone’s speakers and microphones emit and capture high-frequency acoustic signals (ASs). To the best of our knowledge, this is the first instance of employing the Doppler effect generated by the high-frequency AS in response to keystroke activity as a distinctive user feature. Our definition of “keystroke behavior” encompasses the motions involved in tapping screen buttons while holding the smartphone, effectively capturing unique user attributes without necessitating any special procedures or passwords. Our initial experiments have convincingly shown that the AS Doppler effect, triggered by keystroke actions, is uniquely identifiable per user during button presses. Subsequently, we utilized a convolutional autoencoder (CAE) to distill keystroke behaviors from the reflected signals, employing an one-class support vector machine (OCSVM) for user authentication and identification processes. We then implemented a prototype of this scheme on smartphones and rigorously tested its performance across four real-world scenarios. The outcomes are promising, demonstrating that our scheme not only withstands disturbances from noise and light but also achieves an impressive average accuracy rate of 95.08%. Regarding security, it effectively thwarts replay and record attacks, further underscoring its robustness and reliability.

Recent advances in millimeter wave (mm-wave) technologies have inspired various communications exploiting the large spectrum resources. Among which, the E-band, i.e., the 71-76 and 81-86 GHz frequency bands, has an ultra-wide bandwidth of 10 GHz and can potentially provide tens of Gigabits-per-second (Gbps) data rates. The E-band mm-wave is thus considered a candidate for building high-capacity wireless backhauls, especially in long-range transmission scenarios. In order to evaluate E-band link performance in real propagation environments, we conducted several outdoor experiments. Here we report one experiment across a salt lake in Qinghai Province of China, and another across the sea near Sanya Bay of South China Sea, both having a line-of-sight (LOS) path distance of around 12 km. An E-band system with highly-directive and dual-polarized Cassegrain antennas, operating at a center frequency of 74 GHz and supporting a signal bandwidth up to 1 GHz, was used. Signals with different modulation schemes and symbol rates were transmitted through the long-range channels and finally recorded at the receiver side. Based on the obtained data, we analyze E-band link performance. The results show that 2-2.5 Gbps uncoded data rates can be achieved with relatively low bit error rates (BERs) by using 16- and 32-QAM in co-polarized single-input single-output (SISO) links. When higher-order modulation schemes are used, BERs increase accordingly. The 64-QAM transmission provides a maximum data rate of 3 Gbps but has a BER of 10-1. This work indicates that an E-band long-range SISO link can achieve a multiple-Gbps data rate over a below 1-GHz bandwidth, and by using multiple-antenna technologies, there is a potential of boosting data rates to reach tens of Gbps. Hence, we foresee that E-band mm-wave can replace fiber optics in various long-distance backhaul scenarios.

With the rapid development of intelligent applications, many Internet of Things (IoT) devices are deployed in various application scenarios, playing an extremely important role. Remote attestation is an important method to ensure the software integrity of these devices and protect them from several attacks. Due to the lack of security hardware and no support of hardware extensions for Class-1 IoT devices, it is particularly important to design a suitable remote attestation scheme for these devices. In this paper, we first propose the delayed observation mechanism to alleviate the problem that the software-based remote attestation scheme is not suitable for wireless networks. At the same time, we propose a ”filling memory at attestation-time” mechanism, which solves the problem that attackers hide malicious code through return-oriented programming. Finally, we introduce a reputation mechanism to assist our attestation, and adopt the principle of ”making higher-performance verification nodes take on more work” to greatly reduce the time-consuming attestation. We analyze the security of the scheme and implement it on a UNO-R3 development board to prove its practicability and effectiveness. Compared with traditional software-based attestation schemes, our scheme can reduce the attestation time and resist proxy attacks.

The fifth-generation (5G) mobile communication technology has already deployed commercially and become a global research focus. The new features of 5G include unlimited information exchange, a large variety of connections with independent energy, and diversified high transmission rate services. Collective synergy of services is expected to change the way of life and future generations and introduce new converged services to the ICT industry. Different application services have to meet differentiated security demands. From the perspective of security, in order to support the multiservice of 5G services, it is necessary to consider the new security mechanism driven by the service. Based on 5G massive data stream, the 5G system can provide customized real-world services for potential users and reduce the user experience gap in different scenarios. However, 3GPP Extensible Authentication Protocol (EAP), which is the present entity authentication mechanism for the 5G service layer, is only an individual authentication architecture and unable to fulfill the flexible security objectives of differentiated services. In this paper, we present a new hierarchical identity management framework as well as an adaptable and composable three-factor authentication and session key agreement protocol for different applications in 5G multiservice systems. Finally, we propose an authorization process by combining with the proposed three-factor authentication mechanism and Service-Based Architecture (SBA) proposed by the 3GPP committee. The proposed mechanism can concurrently provide diverse identity authentication schemes corresponding to four different security levels by easily splitting or assembling three-factor authentication protocol blocks. The proposed scheme can be simultaneously applied to a variety of applications to improve the efficiency and quality of service and reduce the complexity of the whole 5G multiservice system, instead of designing or adopting several different authentication protocols. The performance evaluation results indicate that the proposed scheme can guarantee the multiple security of the system with ideal efficiency.