Vehicular Ad Hoc Networks (VANETs) are essential components of Intelligent Transportation Systems (ITS) and Vehicular Social Networks (VSN). As the number of connected vehicles continues to grow, the importance of ensuring security and privacy within VANETs becomes paramount. Robust authentication protocols are essential to safeguard vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications, given the vulnerability of the open wireless communication medium in VANETs to interception and manipulation. While researchers are actively developing authentication and privacy schemes to secure message exchanges, existing solutions have not fully satisfied all the security and privacy requirements, thereby fueling ongoing research in this field. A significant challenge in this context is balancing the conflicting goals of privacy—protecting sensitive information from unauthorized access—and traceability—ensuring accountability by identifying malicious actors. This paper presents a comprehensive overview of VANETs, covering their key components, prevalent attack types, and the security and privacy prerequisites essential for effective authentication and privacy mechanisms. Specifically, the paper delves into the realm of identity-based authentication schemes within VANETs, subjecting them to rigorous evaluation based on security, privacy, and scalability. The primary objective is to empower the research community to design and implement efficient and secure authentication schemes, minimizing communication and computational overhead while ensuring resilience against a multitude of potential attacks.

With the vast development of Internet-of-Things (IoT) ecosystem, various types of information, such as healthcare records and physical resources, are integrated for different types of applications. Due to the sheer number of connected IoT devices, which generate a large amount of data, Distributed Ledger Technology, such as Blockchain and IOTA have been recently applied in developing access control models, yet they involve significant energy due to mining, low throughput, non-scalable, and computational overhead that is not acceptable for IoT resource-constrained devices. In this paper, we propose a Scalable Decentralized and Lightweight Access Control framework (SDAC) by using the IOTA platform. IOTA is an emerging distributed ledger technology that has significant features for IoT, such as zero fees transactions, scalability, security and energy efficiency. The proposed SDAC aims to improve security, authorize, and authenticate users when accessing data by using the IOTA Masked Authenticated Messaging (MAM) protocol. MAM ensures access control by encrypting and granting permission to only authorized users. The experimental results indicate that IOTA MAM is a feasible solution that can be used for managing authorization in the IoT domain.

In the Internet of things (IoT), security and privacy issues are a fundamental challenge determining the successful implementation of many IoT applications. Distributed ledger technology (e.g., Blockchain) offers a great promise to solve these issues. Blockchain-based solutions support security and privacy, yet they involve significant energy due to mining, low throughput, and computational overhead that is not acceptable for IoT resource-constrained devices. In this paper, we propose an energy-efficient Privacy-Preserving Distributed Intelligence approach (PPDI) by adopting the IOTA technology. IOTA is an emerging distributed ledger technology that allows for zero fees transactions for the IoT. The proposed PPDI aims to address the privacy issues in the IoT by using the IOTA Masked Authenticated Messaging (MAM) protocol. MAM ensures privacy by encrypting and granting permission to authorized users to access data. This paper presents a healthcare scenario that demonstrate how IOTA MAM can be used to address the privacy issue in the IoT. The experimental results clearly show that IOTA MAM is a feasible solution that can be used to solve privacy related issues in the IoT domain.

Live virtual machine migration is a technique often used to migrate an entire OS with running applications in a non-disruptive fashion. Prior works concerned with one-to-one live migration with many techniques have been proposed such as pre-copy, post-copy and log/replay. In contrast, we propose VMScatter, a one-to-many migration method to migrate virtual machines from one to many other hosts simultaneously. First, by merging the identical pages within or across virtual machines, VMScatter multicasts only a single copy of these pages to associated target hosts for avoiding redundant transmission. This is impactful practically when the same OS and similar applications running in the virtual machines where there are plenty of identical pages. Second, we introduce a novel grouping algorithm to decide the placement of virtual machines, distinguished from the previous schedule algorithms which focus on the workload for load balance or power saving, we also focus on network traffic, which is a critical metric in data-intensive data centers. Third, we schedule the multicast sequence of packets to reduce the network overhead introduced by joining or quitting the multicast groups of target hosts. Compared to traditional live migration technique in QEMU/KVM, VMScatter reduces 74.2% of the total transferred data, 69.1% of the total migration time and achieves the network traffic reduction from 50.1% to 70.3%.

With the development of the theory and technology of wireless sensor networks (WSN), location-based applications, such as location-based access control, pose new challenges. In order to improve the accuracy of node localization, the energy consumption must be considered in conjunction with security. Improving the accuracy of node localization as much as possible under the premise of ensuring the security of the localization process forms the basis of location-based applications in wireless sensor networks. In this paper, a secure localization method of nodes based on the congruity of time is proposed. This method does not need to meet time synchronization conditions between user nodes and base stations. It calculates the congruity of time according to the communication delay between nodes, and then estimates the location of the user node. It can ensure the accuracy of localization and the security of localization processes.