Sharif Digital Repository

Public-key plays a significant role in today's communication over the network. However, current state-of-the-art public-key encryption (PKE) schemes are too complex to be efficiently employed in resource-constrained devices. Moreover, they are vulnerable to quantum attacks and soon will not have the required security. In the last decade, lattice-based cryptography has been a progenitor platform of the post-quantum cryptography (PQC) due to its lower complexity, which makes it more suitable for Internet of Things applications. In this article, we propose an efficient implementation of the binary learning with errors over ring (Ring-BinLWE) on the reduced instruction set computer-five (RISC-V)... 

This article presents the theory and implementation of a quadrature and differential RF front-end receiver. Combining balun, low-noise amplifier (LNA), mixer, and oscillator in a single stage, the proposed circuit, named the Blixator, is well suited for low-power applications. The baseband's transimpedance amplifier (TIA) also shares part of its dc current with the Blixator cell, resulting in sub-milliwatt power consumption. To avoid additional power and area by quadrature LO generation, the I/Q signals are generated at RF, employing the inductors already required for providing the dc current path of the LNA transistors. The expressions for gain, noise figure (NF), and phase noise of the... 

Internet-of-Things (IoT) devices have a strict necessity for power consumption to achieve the expected battery life. Therefore, measuring and optimizing the energy consumption of IoT nodes are essential. IoT nodes feature extreme current consumption range over 100 dB between their operating modes. The main focus of this article is to design and implement a low-power and low-cost current measurement circuit, which can be integrated into IoT nodes. A new pass element is introduced for measuring the current consumption. This element is placed in the current path to measure current over a high dynamic range with a constant voltage drop. The introduced pass element consists of a capacitor and... 

This article reports the development of a new smart electrocardiogram (ECG) monitoring system, consisting of the related hardware, firmware, and Internet of Things (IoT)-based web service for artificial intelligence (AI)-assisted arrhythmia detection and a complementary Android application for data streaming. The hardware aspect of this article proposes an ultralow power patch sampling ECG data at 256 samples/s with 16-bit resolution. The battery life of the device is two weeks per charging, which alongside the flexible and slim (193.7 mm times62.4 mm times8.6 mm) and lightweight (43 g) allows the user to continue real-life activities while the real-time monitoring is being done without... 

Mobile portable embedded devices are becoming an integral part of our daily activities in the vision of Internet of Things (IoT). Nevertheless, due to lack of mobility support in the IPv6 routing protocol for low-power and lossy networks (RPLs), which is standardized for multihop IoT infrastructures, providing reliable communications in terms of packet delivery ratio (PDR) in mobile IoT applications has become significantly challenging. While several studies tried to enhance the adaptability of RPL to network dynamics, their utilized routing metrics have prevented them from establishing long-lasting reliable paths. Furthermore, the stochastic parent replacement policy in the standard version... 

Machine-to-Machine (M2M) communication is an important type of communication in the Internet-of-Things (IoT). How to send data in these high-density communications using relay selection can help improve the performance of this type of communication in various applications. In addition, the possibility of simultaneous use of different Radio Frequency (RF) interfaces helps to use the spectrum more efficiently. In this work, we try to further use machine communication RF equipment and improve the average data rate of networks in some applications such as the IoT, which have their own bandwidth requirements. Therefore, we provide an optimization algorithm for relay selection as well as the... 

User and device biometrics are proven to be a reliable source for authentication, especially for the Internet-of-Things (IoT) applications. One of the methods to employ biometric data in authentication are fuzzy extractors (FE) that can extract cryptographically secure and reproducible keys from noisy biometric sources with some entropy loss. It has been shown that one can reliably build an FE based on the learning parity with noise (LPN) problem with higher error-tolerance than previous FE schemes. However, the only available LPN-based FE implementation suffers from extreme resource demands that are not practical for IoT devices. This article proposes a lightweight hardware/software (HW/SW)... 

In this article, we propose a lightweight security scheme for ensuring both information confidentiality and transmission resiliency in the Internet-of-Things (IoT) communication. A single-Antenna transmitter communicates with a half-duplex single-Antenna receiver in the presence of a sophisticated multiple-Antenna-Aided passive eavesdropper and a multiple-Antenna-Assisted hostile jammer (HJ). A low-complexity artificial noise (AN) injection scheme is proposed for drowning out the eavesdropper. Furthermore, for enhancing the resilience against HJ attacks, the legitimate nodes exploit their own local observations of the wireless channel as the source of randomness to agree on shared secret... 

Fog computing provides a distributed computing paradigm that executes interactive and distributed applications, such as the Internet of Things (IoT) applications. Large-scale scientific applications, often in the form of workflow ensembles, have a distributed and interactive nature that demands a dispersed execution environment like fog computing. However, handling a large-scale application in heterogeneous environment of fog computing requires harmonizing heterologous resources over the continuum from the IoT to the cloud. This paper investigates offloading and task allocation problems for orchestrating the resources in a fog computing environment where the IoT application is considered in... 

The Internet of Things (IoT) is a new model that contributes to connect heterogeneous objects and devices. It can share information with any device globally. Furthermore, the sensor technologies, communications, networks, and cloud computing technology in the IoT are expected to be integrated into large-scale monitored spaces. The main infrastructure of monitoring in the IoT is based on wireless sensor networks. Saving energy and expanding the lifetime are significant properties of the sensor’s nodes in these systems. The efficient energy saving projects should develop appropriate energy consumption’s algorithms to improve the lifetime of the networks in the IoT systems. In this paper, a... 

With the exponential growth in the internet of things (IoT) applications such as smart city and e-health, more embedded devices and smart nodes are connected to the network. In order to provide security for such resource-constrained devices, different cryptographic schemes such as public key encryption (PKE) are required. However, considering the high complexity and vulnerability of classic PKE schemes against quantum attacks, it is necessary to consider other possible options. Recently, lattice-based cryptography and especially learning with errors (LWE) have gained high attention due to resistance against quantum attacks and relatively low-complexity operations. During the past decade,... 

While the Internet of Things (IoT) shapes the future of the Internet, communications among nodes must be secured by employing cryptographic schemes such as public-key encryption (PKE). However, classic PKE schemes, such as RSA and elliptic curve cryptography (ECC) suffer from both high complexity and vulnerability to quantum attacks. During the past decade, post-quantum schemes based on the learning with errors (LWEs) problem have gained high attention due to the lower complexity among PKE schemes. In addition to resistance against theoretical (quantum and classic) attacks, every practical implementation of any cryptosystem must also be evaluated against different side-channel attacks such... 

Sensors are among essential building blocks of any Cyber-Physical Systems (CPSs). Acquisition and processing of their sensory data contribute to the power consumption and computation load of the overall CPSs. For data acquisition, the conventional fixed frequency sampling in many such systems is sub-optimal since a sizable number of samples do not contain important information. In this work, we propose a Signal-Dependent Sampling (SDS) method and present its associated circuit implementation. Using the proposed SDS method, the number of retained samples is significantly reduced with little or negligible compromise in the quality of the (reconstructed) signal. The associated error and added... 

Stress is a body's natural way of responding to any kind of demand or challenge that everyone experiences from time to time. Although short-Term stress typically does not impose a health burden, exposure to prolonged stress can lead to significant adverse physiological and behavioral changes. Coping with the impact of stress is a challenging task and in this context, stress assessment is essential in preventing detrimental long-Term effects. The public embracement of connected wearable Internet of Things (IoT) devices, as well as the proliferation of Artificial Intelligence (AI) and Machine Learning (ML) technologies, have generated new opportunities for personalized stress tracking and... 

In this paper, we propose a light-weight jamming-resistant scheme for the Internet-of-Things (IoT) in 5G networks to ensure high-quality communication in a two-hop cooperative network. In the considered system model, a source communicates with a destination in the presence of an untrusted relay and a powerful multi-Antenna adversary jammer. The untrusted relay is an authorized necessary helper who may wiretap the confidential information. Meanwhile, the jammer is an external attacker who tries to damage both the training and transmission phases. Different from traditional frequency hopping spread spectrum (FHSS) techniques that require a pre-determined pattern between communicating nodes, in... 

The Internet-of-Things (IoT) spans various applications in healthcare filed, from smart wearable or implantable sensors to remote monitoring of elderly, and medical device networking. In this paper, a jamming-resistant scheme for the healthcare IoT is proposed to provide secure and reliable data transmission in a two-hop cooperative network, where a source communicates with a destination in the presence of an untrusted relay and an active adversary. The untrusted relay is an authorized necessary helper who may wiretap the confidential information, e.g., the secret measured data of a patient, while the jammer is an external attacker who tries to interrupt the communication. Different from... 

Cooperative relaying can be introduced as a promising approach for data communication in the Internet of Things (IoT), where the source and the destination may be placed far away. In this paper, by taking a variety of realistic hardware imperfections (HWIs) and channels estimation errors (CEEs) into account, the secrecy performance of a three-hop cooperative network with a source, a destination and two consecutive amplify-and-forward (AF) relays is investigated. The relays are considered to be untrusted, i.e., while they are mandatory helpers for data transmission, they may overhear the received signals. We adopt the artificial noise injection scheme, to keep the source message secret from... 

Internet-of-Things (IoT) devices and applications are being deployed in our homes and workplaces. These devices often rely on continuous data collection to feed machine learning models. However, this approach introduces several privacy and efficiency challenges, as the service operator can perform unwanted inferences on the available data. Recently, advances in edge processing have paved the way for more efficient, and private, data processing at the source for simple tasks and lighter models, though they remain a challenge for larger and more complicated models. In this article, we present a hybrid approach for breaking down large, complex deep neural networks for cooperative, and... 

With recent considerable developments in the Internet of Things (IoT), billions of resource-constrained devices are interconnected through the Internet. Monitoring this huge number of IoT devices which are heterogeneous in terms of underlying communication protocols and data format is challenging. The majority of existing IoT device monitoring solutions heavily rely on centralized architectures. Since using centralized architectures comes at the expense of trusting an authority, it has several inherent drawbacks, including vulnerability to security attacks, lack of data privacy, and unauthorized data manipulation. Hence, a new decentralized approach is crucial to remedy these drawbacks. One... 

With IoT devices becoming abundant and WSN applications becoming evermore present, the once dream of ubiquitous connectivity is closer to realization than ever before. but this realization is hindered by many technical problems and lengthy time to markets. Currently, our best practice of feasibility analysis relies in the same simulators used to model and develop the network applications. Because of their broad range and immense usability challenges, these jack-of-all-trades simulators tend to be computation-intensive and hard to work with.Here, we propose a relatively light-weight simulator based on the analytical models of different parts of the network to aid in rapid development and ease...