Abed Ellatif Samhat

• Professor
• Professor at Lebanese University

Emerging cyber threats’ sophistication, impact, and complexity rapidly evolve, confronting organizations with demanding challenges. This severe escalation requires a deeper understanding of adversary dynamics to develop enhanced defensive strategies and capabilities. Cyber threat actors’ advanced techniques necessitate a proactive approach to manag...

Along with the increasing damage of cyberattacks, cyber risk management remains one of the most crucial proactive measures. Risk management aims to identify potential risks, evaluate their attributes, and implement countermeasures to reduce their damages. The cyber security industry and the research literature have established frameworks and platfo...

The Internet of Things (IoT) has succeeded to be one of the important future communication technologies. The evolution of IoT has accelerated along with the emergence of 5G considered as a leading IoT service provider. In this context, the Low Power Wide Area Network (LPWAN) has recently attracted attention as it provides an impeccable infrastructu...

Nowadays, LoRaWAN has become one of the most widely deployed low-power wide-area technologies suitable for Internet of Things applications. Sensor nodes powered by battery sources with a finite lifetime are the most common in these applications. Deploying a massive number of these nodes that send sporadic traffic increases collisions. In this paper...

LoRaWAN has imposed itself as a promising and suitable technology for massive machine-type communications. With the acceleration of deployment, improving the energy efficiency of LoRaWAN networks has become paramount, especially with the limitations of throughput and battery resources. However, LoRaWAN suffers from the Aloha access scheme, which le...

Nowadays, power optimization has become a major interest for most digital hardware designers. Some, traditionally, might stick to offline power estimation especially in early design phases; some others resort to the modern and very promising runtime power management. Therefore, the Online Power Monitoring (OPM) is considered as an important feature...

The pure Aloha access scheme used in LoRaWAN increases the probability of collisions at a large scak, which will lead to a reduction in the packet delivery ratio (PDR) and the network throughput. As a result, Legacy LoRaWAN cannot guarantee quality of service (QoS). However, a heterogeneous LoRaWAN network consists of several Internet of Things (Io...

Elliptic Curve Digital Signature Algorithm (ECDSA) is a crucial au- thentication component of many modern internet and communica- tion systems. It is used in different domains such as cryptocurrency, IoT, e-health, e-banking, e-governance, etc. Due to the spread of open, distributed and collaborative systems brought by the sharing economy, the surg...

Nowadays, power optimization has become a major interest for most digital hardware designers. Some, traditionally, might stick to offline power estimation especially in early design phases; some others resort to the modern and very promising runtime power management. Therefore, the Online Power Monitoring (OPM) is considered as an important feature...

Machine Learning (ML) is the process of developing Artificial Intelligence (AI) in computers, where the generated models are trained using appropriate learning algorithms and training data. For many machine learning techniques, especially the ones related to supervised methods, the construction of the training data highly affects the quality and ac...

Power optimization has become a major concern for most digital hardware designers, particularly in early design phases and especially in limited power budget systems (battery-operated hand-held devices, electro-optical pluggable modules, IoT and green energy systems, etc.). Subsequently, early power consumption estimation at design time is crucial...

When high speed and high performance are key features of a specific FPGA-based system, increase in energy consumption becomes the main hurdle to be tackled while keeping a trade-off between speed, performance and power consumption. Therefore, power optimization has become a major concern for most digital hardware designers, particularly in early de...

Many today’s companies use Smart Contracts to represent and execute their business processes. Smart contracts are self-executed programs running over blockchain. In this context, composite smart contracts are used to represent collaborative business processes. A composite smart contract is a smart contract that needs to execute other contracts usin...

With the advancement and the wide deployment of the Internet of Things, Low Power Wide Area Network (LPWAN) technologies will respond to applications requiring low power and long range features. In this context, mobility is an additional requirement needed by several applications including supply chain monitoring and health-care supervision. Proxy...

In this paper we have presented an automated and centralized data generation and hybrid acquisition system. First of all, we have described its various modules: high-level hardware covering the internal FPGA logic (including interfacing options) and the digital and analog parts; and the software aspect covering both the firmware alternatives and th...

Estimating solar rooftop potential at a national level is a fundamental building block for every country to utilize solar power efficiently. Solar rooftop potential assessment relies on several features such as building geometry, location, and surrounding facilities. Hence, national-level approximations that do not take these factors into deep cons...

Very few organizations can afford the necessary infrastructure for genomic data analytic, which requires a very large amount of storage and computational resources. In this context, cloud computing platforms can be adopted as a practical solution for storage and computations. However, sharing such sensitive information with cloud providers can lead...

Buildings classification using satellite images is becoming more important for several applications such as damage assessment, resource allocation, and population estimation. We focus, in this work, on buildings damage assessment (BDA) and buildings type classification (BTC) of residential and non-residential buildings. We propose to rely solely on...

Semantic Segmentation of buildings present in satellite images using encoder-decoder like convolutional neural networks is being achieved with relatively high pixel-wise metric scores. In this paper, we aim to exploit the power of fully convolutional neural networks for an instance segmentation task using extra added classes to the output along wit...

Blockchain brings many added values to modern business systems. However, Blockchain-based applications with massive IoT devices experience some limitations. The limitations are due to the linear structure and the consensus algorithms used in Blockchain that consume the participating nodes' considerable resources. In addition, IoT devices are genera...

Conventional cryptographic methods are not appropriate for IoT environments due to the specific IoT devices constraints, such as memory usage, time and computational costs. This leads to the emergence of the lightweight cryptography field. This paper investigates the different lightweight cryptographic design methods and proposes an IoT-based crypt...

Modern IT technologies shaped the shift in economic models with many advantages on cost, optimization, and time to market. This economic shift has increased the need for transparency and traceability in supply chain platforms to achieve trust among partners. Distributed ledger technology (DLT) is proposed to enable supply chains systems with trust...

IOTA is a distributed ledger technology (DLT) platform proposed for the internet of things (IoT) systems in order to tackle the limitations of Blockchain in terms of latency, scalability, and transaction cost. The main concepts used in IOTA to reach this objective are a directed acyclic graph (DAG) based ledger, called Tangle, used instead of the c...

Data transparency is essential in the modern supply chain to improve trust and boost collaboration among partners. In this context, Blockchain is a promising technology to provide full transparency across the entire supply chain. However, Blockchain was originally designed to provide full transparency and uncontrolled data access. This leads many m...

Pseudo-Random Number Generator of Chaotic Sequences (PRNG-CS) has caught the attention in various security applications, especially for stream and block ciphering, steganography, and digital watermarking algorithms. Indeed, in all chaos-based cryptographic systems, the chaotic generator plays a vital role and exhibits appropriate cryptographic prop...

The use of blockchain (BC) technology for IoT-based collaboration platforms is still hindered by its inherent properties, namely, the need for ever-increasing storage and the low scalability. In this paper, we investigate the interoperability requirements between BC and tangle distributed technologies. We propose a new decentralization architecture...

The Internet of Things (IoT) is a new emerging system of interconnected devices that experiences significant growth in a wide variety of applications. The rising communication technologies for IoT are the Low Power Wide Area Networks (LPWANs) having long range, low cost and low power characteristics. In this context, an important part of the applic...

In this paper, privacy preserving at the cloud side is enabled by adopting Homomorphic Encryption (HE) as a major solution for protecting users’ sensitive data. As a Proof Of Concept (POC), we take the case of a university that is adopting the cloud as a practical method for storing and operating over its private data. The main contribution of this...

Ensuring the correctness of smart contracts is of paramount importance to achieve trust and continuity in the Blockchain-based business process execution. Due to the immutable nature of distributed ledger technology on the blockchain, a smart contract should work as intended before using it. Any bugs or errors will become permanent once published a...

To achieve trust and continuity in the smart contracts-based business process execution, the verification of such smart contracts is mandatory. A blockchain-based smart contract should work as intended before using it. Due to the immutable nature of blockchain, any bugs or errors will become permanent once published and could lead to huge economic...

The integration of IoT communication technologies such as Low Power Wide Area Networks (LPWAN) is essential in today systems including supply chain, healthcare, autonomous vehicle, etc. In such environments there is an increase in IoT applications that require End Devices (EDs) mobility within similar or heterogeneous LPWAN technologies. Supporting...

In this paper, we consider Homomorphic Encryption (HE) to process over encrypted data to achieve users privacy. We present a framework solution that provides a high level of security for the symmetric HE algorithms. The proposed solution introduces a dynamic structure and a dynamic diffusion primitives that enhance existing symmetric HE algorithms...

In this paper, we consider the mobility of an end device (ED) in low-power wide area networks (LPWAN) and we focus on the continuity of the ED session with the application server when this ED is moving from the coverage of one operator to that of another one. One of the methods to achieve the continuity of the session after roaming is the use of an...

In this paper, we consider the selection of the appropriate technology in IoT environments. Specific IoT-based applications, including innovative tracking solutions in automotive or transportation systems , require the mobility of the IoT device under different IoT technologies. Selecting the best technology for connectivity based on several criter...

To take advantage of IPv6 stack in IoT technologies, an efficient header compression scheme is required. Since 2004, many IPv6 header compression schemes have been proposed and some of them have been standardized by the IETF. In [9], Static Context Header Compression (SCHC) mechanism has been designed for Low Power Wide Area Networks (LPWAN). SCHC...

VANET aims to improve safety for all road users. Vehicles exchange safety messages over wireless communication links which are prone to multiple attacks. To enhance the existing security of V2V communications, we propose in this paper a security framework based on vehicles behavior analysis. We define a Hybrid Trust Model (HTM) and a misbehavior de...

Intelligent Transportation System (ITS) aims to provide innovative services in the field of road transport and traffic management. This field includes infrastructure, vehicles and users, and interfaces with other modes of transport. Vehicles are capable of exchanging information by radio to improve road safety or allow internet access for passenger...

In this paper, we present a new Somewhat Homomorphic Encryption (SHE) scheme using computation over complex numbers. We then use Bootstrapping technique to make the scheme Fully Homomorphic (FH) and supports unbounded number of circuit depth. In addition to its homomorphic properties and security level, a main characteristic of the proposed new sch...

Trustworthy communication in VANET Network is essential to provide functional, efficient and reliable traffic safety applications. The main concern arises on how to maintain only the trustworthy participants and revoke the misbehaving ones. In this paper, we propose a new framework for the certificate revocation process within VANET. This process c...

In the multihop IEEE 802.15.5 networks, all the devices compete to the resources of a shared superframe. In order to distribute these resources in a fair and satisfactory manner among the competing devices, we propose a distributed optimization framework for resource allocation scheme in an IEEE 802.15.5 hop-1. For this purpose, we introduce in thi...

In this paper, we consider the privacy issue in cloud systems by using Homomorphic Encryption (HE) to provide secure computing at the cloud side. We use Domingo Ferrer (DF) homomorphic scheme to accomplish this task. Before implementing DF in a cloud scenario, we resolve the two main problems of it that are sensitivity to known plain-text attack an...

In this paper, we consider Homomorphic Encryption (HE) to process over encrypted data in order to achieve user privacy. We present a framework solution to provide a high level of security for the symmetric HE algorithms. The proposed solution introduces a dynamic structure and dynamic diffusion’s primitives that enhance existing symmetric HE algori...

The rapid growth of IoT applications usage enables the Internet connectivity of a massive number of devices using different technologies. Most of these technologies, such as Low Power Wide Area Networks (LPWANs), are non-IP due to the difficulties of using IP on constrained devices. These nodes are characterized by more constraints with respect to...

In this paper, we consider Homomorphic Encryption (HE) to process over encrypted data in order to achieve user privacy. We present a framework solution to provide a high level of security for the symmetric HE algorithms. The proposed solution introduces a dynamic structure and dynamic diffusion’s primitives that enhance existing symmetric HE algori...

AC (Access Control) is the process of ensuring that an authenticated user accesses only what he or she is authorized to do with respect to certain models and security policies. In business collaboration systems, services are designed to conduct actions requested by a customer, using service provider's infrastructure. In such context, the agreement...

The shared superframe multihop nature of wireless personal area networks (WPANs) poses fundamental challenges to the design of effective and optimal resource allocation algorithms with respect to resource utilization and fairness across different network devices. In this paper, we propose a distributed optimization framework for resource allocation...

In this paper, we consider blockchain technology that enabled the existence of digital currency and we investigate Bitcoin cryptocurrency application. This technology nowadays represents a new feature that replaces existing client-server core system on top of some distributed systems with many additional features such as high availability, resistan...

Recently, the evolution of low-power wide area networks (LPWANs) provides Internet of Things (loT) with an approach between the short-range multi-hop technology and the long-range single-hop cellular network technology. LPWANs provide connectivity by using long-range communication with a low data rate in unlicensed bands. They are developed to sati...

In this paper, we discuss a set of solutions that are proposed in order to run IPv6 over IoT and we investigate its applicability over the three Low Power Wide Area Networks (LPWANs) technologies: LoRaWAN, DASH7, NB-IoT. LPWANs are wireless technologies that are used to connect things to the Internet. These technologies are characterized by their l...

In a multi-operator shared network, an appropriate decision is needed for how much to share resources in order to maintain user satisfaction, while maximizing cooperation benefits. In this paper we investigate resource sharing in a three operators sharing system. The study focuses on the value of the sharing factor, which is the percentage of the o...

Homomorphic Encryption (HE) is a new cryptographic topic that allows untrusted parties to compute over encrypted data. This new encryption scheme is very famous in a cloud scenario, because it leverages cryptographic techniques in the cloud by allowing it to store encrypted data, and to process encrypted query over it. In this paper, we consider tw...

Cloud Computing is a kind of internet-based computing that provides shared storage and processing resources. One main drawback of this technique is that users and companies will give the permission to a third party to access their sensitive data. Homomorphic Encryption came as a new cryptographic research topic to resolve the concerned problem by p...

In a shared radio access network, a user can be served through the network of his home operator or the network of another service operator in the sharing system. Consequently, when the home operator is unable to serve its user, and there is more than one available service operator, a selection decision must be made. The decision must consider the s...

In this paper, we model the interaction between the operators of a multi-operator sharing system using Markov chain. We investigate three pricing strategies to set the financial conciliation for the service cost between operators. We also evaluated different resource sharing factors to highlight the impact of such sharing. Results in terms of block...

Inthis paper, weconsider a Trust Model with Group Leader (GL)-based communication in VANET. This model is used to classify vehicles based on their trustworthiness and elect potential GLs. We propose a security risk assessment methodology and we apply it to our Trust Model. This methodology is used for identifying threats, assessing the risk involve...

The design of a Homomorphic Encryption (HE) algorithm that allows computation over the encrypted data is required in real world modern applications to preserve the privacy. Such applications include Cloud Computing, shared storage, processing resources, etc. The existing solutions are not practical for real world applications. Asymmetric approaches...

VANET is an emergent technology with promising future as well as great challenges especially in its security. In this paper, we focus on VANET security frameworks presented on three parts. The first presents an extensive overview of VANET security characteristics and challenges as well as requirements. These requirements should be taken into consid...

The availability of a wide variety of access technologies provides end- users (clients) with access to more than one communication network. In addition, service/content replication has become a trivial approach i n overlay networks to provide a high availability of data and better Quality of Service (QoS). In this paper, we consider a multi-homed...

In this paper, we propose a new neural dynamic block cipher based on a combination between Artificial Neural Network (ANN) and an efficient nonlinear function. A dynamic construction method of synaptic weight matrices is achieved by updating the weight matrices after each validate time and the problem of reversibility is resolved. The main advantag...

In fifth generation mobile network, Radio Access Network sharing is an attractive solution for operators to counter the traffic growth and build cost-effective networks in order to improve coverage and capacity at reasonable investments and operational costs. It consists of sharing radio access resources between two or more operators. In such multi...

In this paper, three pricing scenarios are proposed to set the transaction cost of the inter-operators agreement in a multi-operator cooperative environment. An analysis, of the operators' profits, is performed for these cooperation scenarios and different price sharing models are investigated for comparison. First, we present a hybrid decision alg...

We investigate in this paper the access selection and joint pricing problem in multi-operator wireless networks. The problem is formulated as a Stackelberg game, where cooperating service operators first set the service price to maximize their revenue. Then, the home operator of the mobile user performs the access selection process among the servic...

In this paper, we investigate a security architecture for V2V communication that ensure integrity, confidentiality, anonymity, authenticity and non-repudiation. Based on IEEE 1609.2 Standard, we propose group-based V2V authentication and communication for safety message dissemination with lightweight solution, decentralized via group leaders (GLs),...

In this paper, a novel mechanism for access control and resource allocation in a parent/child IEEE 802.15.3 network is proposed. The main objective is twofold; first the idea of using a dynamic superframe size that ensures the efficient use of the superframe is implemented; second, two approaches for resource allocation among child PicoNet Coordina...

In this paper, we propose a novel admission control and centralized channel time allocation algorithm for two-hop communications based on the IEEE 802.15.5 specifications. The first contribution is the introduction of a dynamic superframe size for efficient resource utilization. The second contribution adopts the use of a threshold concept and a fl...

n this paper, a novel two-tier mechanism for the access control and resource allocation of a two-hop high data rate IEEE 802.15.5 network is proposed. One of the main contributions in this proposal is the use of a dynamic superframe size in the IEEE 802.15.5. Additionally, the ideas of using a superframe utilization threshold and a channel time all...

In this paper, we perform a business analysis of our hybrid decision algorithm for the selection of the access in a multi-operator networks environment. We investigate the ability of the operator to express his strategy and influence the access selection for his client. In this purpose, we study two important coefficients of the previously proposed...

In this paper, we propose a hybrid decision algorithm for the selection of the access in multi-operator networks environment, where competing operators share their radio access networks to meet traffic and data rate demands. The proposed algorithm guarantees the user satisfaction and a global gain for all cooperating operators. Simulation results p...

The IEEE 802.15.5 MAC enables high-rate mesh communications between devices in a wireless personal area network (WPAN). The channel time allocation (CTA) scheduler plays an important role in sizing CTAs within each superframe. In this paper, we propose an efficient admission control and centralized CTA mechanism for a hop-2 mesh communication in th...