As Internet of Things (IoT) technology continues to advance swiftly, a growing array of IoT devices is being assimilated into the industrial IoT framework. However, ensuring secure and efficient transmission of data from IoT devices has become a key technological focus in current research on the development of industrial IoT. Attribute encryption technology is an effective encryption technique that ensures data security; meanwhile, proxy re-encryption technology allows proxies to encrypt original ciphertext into new ciphertext without accessing any plaintext information. The combination of these two technologies enables secure transmission of data among users with different attributes. However, the high computational overhead remains a significant factor limiting the development of this solution. IoT data needs to be shared not only among different units within the same domain but also across units in different domains. Securing shared data has emerged as a pivotal area of focus in contemporary research. In this article, we propose an improved fine-grained proxy re-encryption scheme for cross-attribute domains, which not only facilitates simple cross-domain data sharing but also enhances encryption efficiency. Security proofs demonstrate the adequacy of our proposed scheme, and performance analysis indicates its superiority over other solutions in certain aspects.

LoRa networks have been deployed in many orchards for environmental monitoring and crop management. An accurate propagation model is essential for efficiently deploying a LoRa network in orchards, e.g., determining gateway coverage and sensor placement. Although some propagation models have been studied for LoRa networks, they are not suitable for orchard environments, because they do not consider the shadowing effect on wireless propagation caused by the ground and tree canopies. This article presents FLog , a propagation model for LoRa signals in orchard environments. FLog leverages a unique feature of orchards, i.e., all trees have similar shapes and are planted regularly in space. We develop a three-dimensional model of orchards. Once we have the location of a sensor and a gateway, we know the media that the wireless signal traverses. Based on this knowledge, we generate the First Fresnel Zone (FFZ) between the sender and the receiver. The intrinsic path loss exponents of all media can be combined into a classic Log-Normal Shadowing model in the FFZ. Extensive experiments in almond orchards show that FLog reduces the link quality estimation error by 42.7% and improves gateway coverage estimation accuracy by 70.3%, compared with a widely used propagation model. The source codes and dataset are released at https://github.com/ycucm/Flog .

Multi-signature protocols allow a group of signers to collectively generate a single signature for a shared message. In the context of a decentralized blockchain, multi-signature schemes play a pivotal role in reducing the signature size. Recently, several multi-signature methods have emerged in the literature, some operating in discrete-log settings and others in lattice settings. However, many of the existing lattice-based multi-signature schemes incur high computation costs and online round complexity. Traditional public key-based multi-signature schemes are susceptible to quantum threats, and they are computationally intensive as well. A lattice-based multi-signature can provide robust security, which often falls short in terms of efficiency when it comes to round complexity. In this article, we aim to introduce a single-round lattice-based multi-signature scheme specifically designed for decentralized public blockchains. What sets the proposed scheme apart is its ability to function without the need for trapdoor commitments or sample pre-images, which are common features in existing lattice-based signature methods. Furthermore, we explore some potential applications in a generic Internet of Things (IoT) environment and their integration of the proposed scheme with the blockchain technology. The security of the proposed scheme is based on lattice-hard problems, like Ring-SIS (Shortest Integer Solution) and Ring-LWE (Learning with Errors).

The prolonged lifetime of energy-harvesting (EH) LoRa networks requires that all EH LoRa sensors utilize available harvested energy in an energy-neutral manner to avoid power failures. This requirement is challenging to fulfill due to the unpredictability of ambient-energy sources and the spatio-temporal heterogeneity of sensors’ harvesting abilities. We present RACEME, a novel predictive EH-management framework by exploiting the embedded intelligence capability of EH LoRa devices. It empowers energy-neutral operation in EH LoRa networks by leveraging the spatio-temporal correlation between EH LoRa sensors to optimize the harvested-energy utilization. RACEME is an integrated system that consists of embedded machine learning for predictive EH management on the sensors and online cluster-based data reduction and recovery on the server. To maximize the accuracy of EH predictions, RACEME allows each sensor to implement a machine learning pipeline locally. Coupled with the cluster-based data-reduction feedback from the server, RACEME enables the sensors with higher harvested-energy availability and communication quality to transmit critical data more frequently in a probabilistic manner without sacrificing data quality. Compared with the state of the art, the experimental results reveal that RACEME improves EH-prediction accuracy, network lifetime, and transmission overhead by up to 1.7, 2, and 8 times, respectively.

Intelligent voice systems are widely utilized to control smart home applications, which raises significant privacy and security concerns. Recent studies have revealed their vulnerability to adversarial attacks, replay attacks, and so on. However, these attacks rely on the victim’s voice data. In our work, we investigate a stealthy and command-independent attack that does not necessitate collecting victims’ voices. Our proposed attack, IUAC, misleads the voice system to go against the victim’s will, regardless of the commands delivered. Our core concept is to train highly robust attack commands through the construction of diverse data, rendering the user’s commands negligible. To achieve stealthy attacks, we leverage a high-frequency carrier to construct an inaudible universal adversarial command. Extensive experiments conducted with real-world datasets demonstrate that our attack system attains an average attack success rate of 96% while resisting environmental interference. Moreover, our attack success rate against real-world voice systems is 4.52× higher than the state-of-the-art. Finally, we propose an effective defense mechanism and provide experimental tests to validate its efficacy.

With the widespread adoption of deep learning models in wireless sensing, substantial efforts have been made to develop sophisticated models that improve the accuracy and performance of sensing applications. However, the exploration of potential vulnerabilities in deep learning models has been limited, with existing studies primarily focusing on evaluating wireless adversarial performance in communication or sensing alone. Moreover, there is a lack of a comprehensive definition for attack imperceptibility. In this article, we come up with a definition of the wireless attack imperceptibility for both communication and sensing. Our objective is to create an adversarial perturbation capable of degrading WiFi sensing performance while preserving WiFi communication integrity. To achieve this, we propose WiCAM2.0 to reveal the temporal and spatial attention of a deep neural network, capturing the crucial portions of its input. Then, we design a mask to confine adversarial perturbations in the attended parts only, minimizing the impact on WiFi communication. WiCAM2.0 is a general adversarial framework that integrates adversarial methods such as the Fast Gradient Sign Method and Projected Gradient Descent to generate perturbations, capable of initiating both non-targeted and targeted attacks. We carry out experiments on three popular WiFi sensing applications, including human activity recognition, gesture recognition, and user identification. Extensive experiments are conducted on both public datasets and self-collected datasets.

Water scarcity is nowadays a critical global concern and an efficient management of water resources is paramount. This paper presents an original approach for monitoring Water Distribution Systems (WDSs) through Internet of Things (IoT) that involves the integration of multiple sensors placed across the distribution network to accurately measure water flow. To enhance energy efficiency for green monitoring and communication process, we harness the power of graph theory and graph signal processing to represent in a tunable and accurate way the water flow and simultaneously minimize the number of IoT sensors communicating those measurements. We propose a graph model where water flow is represented as signal on graph and we introduce an algorithm, named GraphSmart, designed to reconstruct the graph signal when certain measurements are unknown or missing. Our framework is applied on a synthetic realistic environment within the context of LoRaWAN (Long Range Wide Area Network), an infrastructure and protocol designed for ultra-low-power IoT devices. Our findings show that GraphSmart significantly reduces energy consumption while ensuring precise flow estimation. Our research demonstrates high potential for energy-efficient and accurate water flow monitoring, paving the way to improve the management of WDSs and enabling water operators to address water scarcity challenges.

Traditional wisdom for network management allocates network resources separately for the measurement and communication tasks. Heavy measurement tasks may compete limited resources with communication tasks and significantly degrade overall network performance. It is therefore challenging for the interference graph, deemed as incurring heavy measurement overhead, to be used in practice in wireless networks. To address this challenge in wireless sensor networks, our core insight is to use power as a new dimension for interference graph estimation (IGE) such that IGE can be done simultaneously with the communication tasks using the same frequency-time resources. We propose to marry power-domain IGE with concurrent flooding to achieve simultaneous measurement and communication in BLE networks, where the power linearity prerequisite for power-domain IGE holds naturally true in concurrent flooding. With extensive experiments, we conclude the necessary conditions for the power linearity to hold and analyze several non-linearity issues of power related to hardware imperfections. We design and implement network protocols and power control algorithms for IGE in multi-hop BLE networks and conduct experiments to show that the marriage is mutually beneficial for both IGE and concurrent flooding. Furthermore, we demonstrate the potential of IGE in improving channel map convergence and convergecast in BLE networks.

Brightness scaling (BS) is an emerging and promising technique with outstanding energy efficiency on mobile video streaming. However, existing BS-based approaches totally neglect the inherent interaction effect between BS factor, video bitrate and environment context. Their combined impact on user’s visual perception in mobile scenario, leading to inharmonious between energy consumption and user’s quality of experience (QoE). In this paper, we propose PEO , a novel user- P erception-based video E xperience O ptimization for energy-constrained mobile video streaming, by jointly considering the inherent connection between a device’s state of motion, video quality and the resulting user-perceived quality. Specifically, by capturing the motion of the on-the-run device, PEO first infers the optimal bitrate and BS factor, therefore avoiding bitrate-inefficiency for energy saving while guaranteeing the user-perceived QoE. On that basis, we formulate the device motion-aware and user perception-aware video streaming as an optimization problem where we present an optimal algorithm to maximize the object function and adapt to user preference, and thus propose an online bitrate selection algorithm. Our evaluation (based on trace analysis and user study) shows that, compared with state-of-the-art techniques, PEO can raise the perceived quality by 23.8%-41.3% and save up to 25.2% energy consumption.

As an emerging learning paradigm, Federated Learning (FL) enables data owners to collaborate training a model while keeps data locally. However, classic FL methods are susceptible to model poisoning attacks and Byzantine failures. Despite several defense methods proposed to mitigate such concerns, it is challenging to balance adverse effects while allowing that each credible node contributes to the learning process. To this end, a Fair and Robust FL method is proposed for defense against model poisoning attack from malicious nodes, namely FRFL. FRFL can learn a high-quality model even if some nodes are malicious. In particular, we first classify each participant into three categories: training node, validation node, and blockchain node. Among these, blockchain nodes replace the central server in classic FL methods while enabling secure aggregation. Then, a fairness-aware role rotation method is proposed to periodically alter the sets of training and validation nodes in order to utilize the valuable information included in local datasets of credible nodes. Finally, a decentralized and adaptive aggregation mechanism cooperating with blockchain nodes is designed to detect and discard malicious nodes and produce a high-quality model. The results show the effectiveness of FRFL in enhancing model performance while defending against malicious nodes.