The increasing congestion of Earth’s orbit due to growing satellite deployments and space debris poses a significant challenge to sustainable space operations. Traditional space surveillance systems rely on centralized architectures, which introduce single points of failure and scalability constraints. This paper proposes a blockchain-based solution, where satellites function as nodes with distinct roles to validate and securely store debristracking data. Simulation results indicate that optimal network performance is achieved with approximately 30 nodes, balancing throughput and response time, representing an approximately $9 \times$ improvement over traditional consensus mechanisms.

As intelligent transportation systems and dense IoT environments expand, efficient and privacy-preserving authentication becomes essential. Traditional centralized methods often suffer from latency, limited scalability, and privacy risks, especially under high user density. This paper presents a centralized group authentication protocol that enables simultaneous, anonymous authentication of multiple users using polynomial interpolation over elliptic curve groups. Each user holds a private share derived from a secret polynomial, and authentication is performed by aggregating their elliptic curve contributions. To ensure operability with small groups, publicly known dummy identifiers are introduced, preserving both functionality and user unlinkability. The protocol also embeds a lightweight key establishment mechanism without requiring explicit key exchange. Security analysis confirms resistance against impersonation, replay, and collusion attacks, while performance results show significant improvements in computation and communication overhead. These features make the scheme well-suited for scalable, privacy-aware authentication in V2X and IoT systems.

Uncrewed Aerial Vehicles (UAVs), commonly known as drones, are widely deployed and often transmit sensitive data via cellular networks, Wi-Fi, or device-to-device (D2D) communication frameworks. Due to their aerial mobility, UAVs are well-suited for a wide range of applications such as military missions, cargo transport, mapping, and agricultural monitoring. However, securing their communications remains a significant challenge. Their continuous movement and frequent data transmissions make secure authentication difficult to maintain, especially as UAVs often need to switch between different network cells during flight. For example, a drone initially connected to cell A may need to handover to cell B as it progresses along its route. This study is designed to present new authentication and handover processes for multiple nodes within a predefined group. The proposed method makes the group handover process simple and low-cost, while also being resistant to various security threats. Compared to a previous handover scheme based on elliptic curves and Lagrange interpolation, the proposed method, leveraging inner product space, demonstrates significantly improved performance. The corresponding test results are also presented.

The rapid expansion of Vehicle-to-Everything (V2X) networks within the Internet of Vehicles (IoV) demands secure and efficient authentication to support high-speed, high-density and mobility-challenged environments. This paper presents a privacypreserving authentication scheme that incorporates batch authentication, mutual authentication, and secure key establishment, enabling users to authenticate one another without a central authority. Our proposed scheme facilitates simultaneous multi-user authentication, significantly enhancing scalability, robustness and security in dynamic IoV networks. Results from realistic implementations show that our method achieves average authentication and verification times of$\mathbf{1 0. 6 1 ~ m s}$and$\mathbf{1. 7 8 ~ m s}$, respectively, for a fleet of$\mathbf{1 0 0}$vehicles, outperforming existing methods. Scalability tests demonstrate efficient processing for larger groups of up to 500 vehicles, where average authentication times remain low, establishing our scheme as a robust solution for secure communication in IoV systems.

Abstract In this paper, we present a review of three widely-used practical square root algorithms. We then describe a unifying framework where each of these well-known algorithms can be seen as a special case of it. The framework with singular curves offers a broad perspective to compare and further improve the existing methods in addition to offering a new avenue for square root computation algorithms in finite fields.

Group authentication is a technique that verifies the group membership of multiple users and establishes a shared secret key among them. Unlike the conventional authentication schemes that rely on a central authority to authenticate each user individually, group authentication can perform the authentication process simultaneously for all the members who participate. Group authentication has been found to be a suitable candidate for various applications in crowded in Internet of Things (IoT) environments, such as swarms of drones for agriculture, military, and surveillance, where a group of devices need to establish a secure authenticated communication channel among themselves. The recently presented group authentication algorithms mainly exploit Lagrange polynomial interpolation along with elliptic curve groups over finite fields. A polynomial interpolation-based group authentication scheme (GAS) has a vulnerability that allows malicious interruption by any single entity in the process. Moreover, this scheme requires each entity to obtain the tokens of all other entities, which is impractical in a large-scale setting. The cost of authentication and key establishment also depends on the number of users, creating a scalability issue. As a fresh approach to eliminate these issues, this work suggests the use of inner product spaces for group authentication and key establishment. The approach with linear spaces introduces a reduced computation and communication load to establish a common shared key among the group members. In addition to providing lightweight authentication and key agreement, this approach allows any user in a group to make a nonmember a member, which is expected to be useful for autonomous systems in the future. The scheme is designed in a way that the sponsors of such members can easily be recognized by anyone in the group. Unlike the other GASs based on Lagrange’s polynomial interpolation, the proposed scheme does not provide a tool for adversaries to compromise the whole group’s secrets by using only a few members’ shares as well as it allows to recognize a nonmember easily, which prevents the denial-of-service attacks from which the former group authentication algorithms suffer.

Ensuring the security of the Internet of Vehicles (IoV) has been a challenging task, particularly due to the high mobility rate of the many elements in the network. With vehicles constantly moving and frequently exchanging data, authentication is crucial for maintaining security. We propose a new approach based on group authentication to handle authentication of several units simultaneously while protecting privacy in an IoV environment. The proposed protocol is designed to perform an authentication and handover process of multiple users within a predefined group. The group authentication based approach ensures privacy of users as the group members’ identification is systematically redefined after each group exchange process. Thus, the proposed scheme is designed to offer a promising solution to security challenges within the IoV environment by simultaneously addressing scalability and protecting the privacy of user data. Additionally, our scheme is resistant to various types of attacks, including offline ID attacks, replay attacks, location spoofing attacks, and replay attacks. Comprehensive tests have been conducted and the results are presented in the analysis section, both in terms of the computational cost and the running times, which reveal that the proposed method demonstrates remarkable practicality when compared to the existing approaches.

Caching and distributing of network packets among devices has been accepted by the research community as a cost-effective method of transferring especially audio-video data among mobile users. Another newly established technology, blockchain, has been successfully applied to decentralized financial systems like Bitcoin. The research on caching and distributing methods has not focused on the security aspect so far. In this article, we present an effective scheme to provide security and integrity of network packets in caching and distribution systems by employing the blockchain technology. Unlike the existing blockchain applications, the proposed protocol requires a lightweight consensus algorithm. Our scheme also allows peers in the network to make correctly addressed inquiries as the packets’ locations are kept in the blocks which are available to any peer in the network. Considering that cryptographic primitives alone are not adequate to prevent malicious network packets among the peers, the proposed blockchain application presents an invaluable tool to prevent malicious packets from leaking into the system and to address which peers own the desired packets. We demonstrate the efficiency of the proposed method by implementing it for Android OS devices and conduct real-time testing on different settings.

The widespread use of new technologies, such as the Internet of Things and machine-type communication (MTC) forces an increase on the number of user equipments (UEs) and MTC devices that are connecting to mobile networks. Inherently, as the number of UEs inside a base station’s (BSs) coverage area surges, the quality of service tends to decline. The use of drone-BS (UxNB) is a solution in places where UEs are densely populated, such as stadiums. UxNB emerges as a promising technology that can be used for capacity injection purposes in the future due to its fast deployment. However, this emerging technology introduces a new security issue. Mutual authentication, creating a communication channel between terrestrial BS and UxNB, and fast handover operations may cause security issues in the use of UxNB for capacity injection. This new protocol also suggests performing UE handover from terrestrial to UxNB as a group. To the best of our knowledge, there is no authentication solution between BSs according to LTE and 5G standards. The proposed scheme provides a solution for the authentication of UxNB by the terrestrial BS. Additionally, a credential sharing phase for each UE in handover is not required in the proposed method. The absence of a credential sharing step saves resources by reducing the number of communications between BSs. Moreover, many UE handover operations are completed in concise time within the proposed group handover method.

Internet-of-Things (IoT) networks are becoming a part of our daily lives, as the number of IoT devices around us are surging. The authentication of millions of connected things and the distribution and management of secret keys between these devices pose challenging research problems. Current one-to-one authentication schemes do not take the resource limitations of IoT devices into consideration. Nor do they address the scalability problem of massive machine type communication (mMTC) networks. Group authentication schemes (GASs), on the other hand, have emerged as novel approaches for many-to-many authentication problems. They can be used to simultaneously authenticate numerous resource-constrained devices. However, existing GAS is not energy efficient and they do not provide enough security for widespread use. In this article, we propose a lightweight GAS that significantly reduces energy consumption on devices, providing almost 80% energy savings when compared to the state-of-the-art solutions. Our approach is also resistant to the replay and man-in-the-middle attacks. The proposed approach also includes a solution for key agreement and key distribution problems in mMTC environments. Moreover, this approach can be used in both centralized and decentralized group authentication scenarios. The proposed approach has the potential to address the fast authentication requirements of the envisioned agile 6G networks, supported through aerial networking nodes.

By introducing high randomness with reduced computational cost, physical layer (PHY) key generation is one of the candidate tools that can be used for the security of the Internet of Things applications. Nonidentical secret keys are one of the main problems of the physical layer (PHY) key generation schemes. In order to address this problem, key verification schemes, which are based on information reconciliation, are used in this article. In the current key verification techniques, the legitimate nodes reveal some information related to their secret keys to eliminate nonidentical bits. In this article, by jointly using PHY key generation with an embedded key, we propose a hybrid key generation and key verification scheme, where the revealed information during the key verification process is negligible, and the verified keys are identical. Numerical results and software-defined radio-based tests show that the proposed verification scheme achieves the requirements of the Industrial Internet of Things systems.

This paper presents a framework for computing successful decoding probability of random network coding (RNC) in wireless networks. As cooperation emerges due to the naturally occurring broadcasting in wireless links, the application of RNC in wireless networks enables random network coded cooperation (RNCC). The theoretical successful decoding probability of RNCC systems is derived by obtaining the ratio of the full rank and the rank deficient matrices. The full rank condition of the global encoding matrix indicates the successful decoding of source symbols. The results of a single relay along with a relay selection scheme are also investigated. The validity of the presented theoretical expressions is demonstrated through identical simulation results. An implementation scenario is also presented to demonstrate the practical usage effectiveness of RNC in real-time applications, by using software-defined radio nodes.

In this work, we describe a new method for computing square roots in finite fields with odd characteristic.