Nowadays, an increasing number of wearable devices have been widely deployed in smart wearable systems to collect health status measures and body information of users. Due to the openness of wireless transmission and the low capabilities of wearable devices in terms of energy and computation, it is of a great challenge to ensure the security of the users’ physiological information. In this paper, we propose a secure and lightweight authentication and key agreement scheme (SLAKA) by using the fuzzy extractor, the cryptographic hash function and the bitwise exclusive-or operation. In SLAKA, mutual authentication between a wearable device (WD) and the mobile terminal (MT) can be achieved, after that, a session key can be negotiated at both ends for future secure communications. Detailed security analysis shows that SLAKA has the resilience against various well-known attacks, such as replay attacks, stolen/lost MT/WD attacks, man-in-the-middle attacks, MT/WD impersonation attacks, password change attacks, anonymity & untraceability attacks, and privileged-insider attacks. Through performance comparison and extensive simulation, SLAKA is demonstrated to be more efficient than the existing schemes, while providing more extractive features and security guarantees.

The tremendous proliferation of smart phones and other smart devices has spurred the explosive growth of delaysensitive high-rate multimedia services, which significantly increases energy consumption in wireless cellular networks. Therefore, it is an important yet challenging issue to carry out resource allocation for cellular networks to meet the quality of service (QoS) requirement in terms of high data rate and, at the same time, achieve high energy efficiency. In this paper, two resource allocation approaches are proposed, where user selection and power allocation are jointly considered, to maximize effective capacity (EC) and effective energy efficiency (EEE), respectively, for a relay-assisted downlink of cellular networks. Channel estimation errors are taken into account to make the proposed approaches more practical. Moreover, to solve the EC maximization problem efficiently, we develop an optimal algorithm based on Lagrange method and Karush-Kuhn-Tucker (KKT) conditions, and derive closed-form optimal solutions for user selection and power allocation at both the base station and relays. For the EEE maximization problem, an iterative algorithm based on the Dinkelbach method is developed to find the optimal solutions. Theoretical analysis and simulation results are presented to demonstrate the performance of the proposed approaches in terms of effective capacity, effective energy efficiency, and delay bound violation probability.

This article presents a robust 3-D received signal strength difference (RSSD) localization algorithm under mixed Gaussian noise in underwater wireless sensor networks (UWSNs) with nonline-of-sight (NLOS) paths. To mitigate the adverse effects, concurrent to absorption and path losses on accurate underwater localization, an Efficient RSSD-based Iterative Estimator (ERIE) in mixed Gaussian noise and NLOS environments is proposed. First, the corresponding nonconvex problem in such environments is formulated, and the direct solution to this problem is not tractable unfortunately. Considering underwater acoustic signal attenuation, an RSSD-based min-max strategy is designed to transform it into a problem minimizing the worst-case loss, combined with the Huber cost function, constitutes a Huber function-based equivalent problem (H-ADMM) solved by alternating direction method of multipliers (ADMM). A compensation matrix is designed based on the H-ADMM solution to compensate for the bias introduced by the transformation, and the corresponding Cramér-Rao lower bound (CRLB) is derived to provide a performance benchmark. Numerical results indicate that the proposed approach achieves a higher localization accuracy than state-of-the-art methods.

In vehicular ad hoc networks (VANETs), vehicles and roadside units (RSUs) utilize open wireless channels to exchange safety-critical data, facilitating real-time decision-making for enhanced road safety and traffic management efficiency in intelligent transportation systems (ITSs). However, the openness of these channels exposes them to various security threats. Malicious adversaries may impersonate RSUs to forge and distribute harmful commands, manipulating vehicular behavior, or masquerade as legitimate vehicles to bypass authentication protocols and gain unauthorized access. Such attacks jeopardize the security and functionality of the VANETs, underscoring the necessity of robust mutual authentication between vehicles and RSUs. Existing centralized trust authority (TA)-dependent schemes for vehicle-to-RSU (V2R) authentication incur high-computational overhead, introduce authentication latency, and cause a single point of failure, particularly in dense traffic scenarios. To address these challenges, we propose efficient, revocable authentication scheme with session key negotiation (ERAS2KN), an efficient and revocable authentication scheme with session key negotiation. By integrating physical unclonable functions (PUFs) with lightweight cryptography, such as one-way hash functions, bitwise xor, and symmetric encryption, ERAS2KN enables rapid mutual authentication and secure session key establishment. Comprehensive security analysis, including informal evaluation, formal security proof based on the real-or-random (RoR) model, and automated validation using AVISPA, confirms ERAS2KN’s resilience against vehicle impersonation, eavesdropping, vehicle/RSU compromise, man-in-the-middle, and other advance attacks. Performance evaluations demonstrate that ERAS2KN surpasses existing schemes by delivering enhanced security features while achieving the lowest computational overhead, communication overhead, and energy consumption cost, making it ideal for high-density VANETs environments.

Vehicular Ad hoc Networks (VANETs) enable vehicles and roadside units (RSUs) to exchange safety-related information over public wireless channels, thereby enhancing transportation system security and efficiency. However, malicious adversaries may impersonate RSUs to disseminate false information or masquerade as legitimate vehicles to gain unauthorized services. To counter such threats, mutual authentication between vehicles and RSUs is crucial. This task is particularly challenging due to the high mobility of vehicles and the resource constraints of both vehicles and RSUs. In this paper, we propose an Efficient and Anonymous Authentication Scheme with Session Key Agreement (EA2S2KA), which leverages Elliptic Curve Cryptography (ECC) and Physical Unclonable Functions (PUFs) to achieve lightweight, fast, and secure authentication. We conduct an informal security analysis, a formal security proof under the real-or-random (RoR) model, and formal security verification using AVISPA, all of which confirm that EA2S2KA resists a broad range of security threats in VANETs. Performance comparisons with recently proposed schemes show that EA2S2KA provides stronger security guarantees while achieving the lowest total computation cost and ranking among the top three in communication efficiency. Furthermore, NS-3 simulations confirm its practicality in large-scale and dynamic environments through evaluations of the authentication success rate, average authentication delay, and authentication message throughput.

Within the Internet of Vehicles (IoVs) framework, vehicles and roadside unit (RSU) exchange safety-related information via public wireless channels to enhance the transportation system's security and efficiency. A potential adversary may impersonate an RSU to send false instructions, misdirecting vehicles, or deceive the RSU into mimicking an authorized vehicle to obtain services. Therefore, mutual authentication between vehicle and RSU is essential. However, this mutual authentication poses a significant challenge, stemming from the swift movement of vehicles and the limited resources available to both the vehicles and RSUs. In this paper, we introduce an anonymous and revocable authentication scheme with session key agreement (ARAS2KA) by using lightweight Hash and XOR operations to achieve fast and robust authentication. Informal security analysis, formal security proof based on ROR model, and security verification with AVISPA demonstrate that ARAS2KA can withstand a wide array of potential security threats within the IoVs environment. The performance analysis—comparing ARAS2KA with recently proposed schemes in terms of computation costs, communication overhead, and security features—demonstrates its superiority. Validated through NS3+SUMO simulations across diverse scenarios, ARAS2KA not only provides enhanced security and efficiency but also proves to be a more suitable solution for the IoVs environment.