Ryma Abassi

• Associate Professor
• Researcher at École Supérieure des Communications de Tunis

L’évolution numérique, que ce soit les progrès de l’internet ou le développement des objets connectés, a provoqué une véritable révolution sociétale. Le domaine de la médecine en bénéficie pleinement, grâce aux avancées technologiques, les services de e-santé permettent d’assurer un suivi en temps réel des patients par les professionnels de la sant...

Peer-To-Peer networks are becoming increasingly common as a mean of transferring files over Internet. In this paper, we describe, first, the design and implementation of our P2P system (MultiPathP2P). This latter is based on the social networks concepts where nodes are identified through their virtual addresses, we have designed our protocol based...

With the help of advanced technology, the automotive industry is in continuous evolution. Modern vehicles are not only comprised of mechanical components but also contain highly complex electronic devices and connections to the outside world. Today's vehicle usually has between 30 and 70 ECUs (Electronic Control Units), which communicate with each...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. May ALLAH have...

Cybersecurity Crisis Management and Lessons Learned From the COVID-19 Pandemic provides cutting-edge research on the best guidelines for preventing, detecting, and responding to cyber threats within educational, business, health, and governmental organizations during the COVID-19 pandemic. It further highlights the importance of focusing on cyberse...

The Internet of Things (IoT) devices produce large amounts of data which increase their susceptibility to cyber attacks. Data Integrity attack is a serious limitation to the evolution of IoT as it leads to bad financial impact or even human fatality. In this work, we will focus on ensuring exchanged data integrity using digital signature for public...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace.

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: Vehi...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: In V...

Wireless sensor networks (WSNs) have been widely used for applications in numerous fields. One of the main challenges is the limited energy resources when designing secure routing in such networks. Hierarchical organization of nodes in the network can make efficient use of their resources. In this case, a subset of nodes, the cluster heads (CHs), i...

With the widespread usage of Internet-enabled devices, the Internet of things (IoT) has become popular and well integrated in different countries nowadays. However, the huge amount of data generated from several smart devices in the same IoT network, security of the network and the limited devices capacities of storage and process are a very big co...

Vehicular Ad-hoc NETwork (VANET) is a decentralized dynamic network of vehicles that move rapidly and communicate with one another to disseminate various types of information and deliver data. However, dishonest vehicles may present in the route and may lead for changing or dropping the content of delivered messages. This latter is a challenge issu...

Wireless sensor networks (WSNs) are ad hoc networks composed mainly of tiny and resource- constrained sensor nodes, and are rapidly growing as a technology for low-cost, large-scale and automated systems to sense and monitor a different range of potential environments. Network Coding (NC) technique has been proposed for these networks for various r...

Vehicular ad-hoc networks (VANETs) allow communication among vehicles using some fixed equipment on roads called roads side units. Vehicular communications are used for sharing different kinds of information between vehicles and RSUs in order to improve road safety and provide travelers comfort using exchanged messages. However, falsified or modifi...

In our previous papers, a new Ant Routing Protocol for Ad-hoc Networks inspired from ant colony optimization was presented. We introduced a new approach which decreases both of nodes energy consumption and routing overhead within the network. The validation of our routing protocol was based on series of simulation. The results show that our new alg...

A Vehicular Ad hoc NETwork (VANET) is a self-organized network formed by connected vehicles, which allows the exchange of useful traffic information in a timely manner. In such a context, evaluating the reliability of transmissions is vital. Trust can be used to promote such healthy collaboration. In fact, trust enables collaborating vehicles to co...

One necessary requirement for the well operation of Vehicular Ad hoc NETworks (VANETs) is assessing the credibility and the accuracy of the received safety related messages. Recently, we proposed a scheme [1] dealing with this demand. After defining [1], it has appeared to us necessary to formally validate it to avoid any conflict or lack situation...

In Vehicular Ad hoc NETworks (VANETs), a major necessity is to enable the receiving vehicles to authenticate the received safety related messages while conditionally preserving the privacy of the real identities of the sending vehicles. In order to achieve the aforementioned objectives, we proposed a Ticket-based Authentication Scheme for VANETs Pr...

Software Defined Networking (SDN) is an emerging technology that introduces a new design for networking. It decouples the hardware and the software for simplifying and hiding the management part of network elements. This technology has also an interesting impact for network security since it affords automation, convergence, etc. We can benefit from...

Wireless sensor networks (WSNs) face some security issues when transmitting data to the base station as these networks involve resources scarcity that needs to be tackled in the routing protocols. More specifically, collected and distributed data are only profitable if their confidentiality is guaranteed. Lately, some approaches have used network c...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: In V...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: One...

Vehicular Ad hoc NETworks (VANETs) are a key part of the Intelligent Transport Systems (ITS) as they constitute an intelligent transport network where vehicles and some infrastructure collaborate to exchange messages about traffic, accidents, etc. In such context, security becomes a key component to ensure that exchanged messages were not modified...

Vehicular ad-hoc networks (VANETs) allow communication among vehicles using some fixed equipment on roads called roads side units. Vehicular communications are used for sharing different kinds of information between vehicles and RSUs in order to improve road safety and provide travelers comfort using exchanged messages. However, falsified or modifi...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: Vehi...

Specifying a security policy (SP) is a challenging task in the development of secure communication systems since it is the bedrock of any security strategy. Paradoxically, this specification is error prone and can lead to an inadequate SP regarding the security needs. Therefore, it seems necessary to define an environment allowing one to “trust” th...

The recent rise of emerging networking technologies such as social networks, content centric networks, Internet of Things networks, etc, have attracted significant attention from academia as well as industry professionals looking to utilize these technologies for efficiency purposes. However, the allure of such networks and resultant storage of hig...

Abstract Emerging technological advances in wireless communication and networking have led to the design of large scale networks and small sensor units with minimal power requirements and multifunctional processing. Though energy harvesting technologies are improving, the energy of sensors remains a scarce resource when designing routing protocols...

Trust allows collaborating entities to cope with their uncertainty especially when these collaborations are the bedrock of the network existence such as in Mobile Ad hoc NETworks (MANET). The trustworthiness of collaborators can be evaluated using reputations. Reputation is an appreciation of the node credibility created through past actions. It ca...

Vehicular communications are expected to share different kinds of information between vehicles. However, the presence of dishonest vehicles in the route may lead to the drop or modification of the content of the exchanged messages. Thus, it is a challenge to find and maintain an efficient route for transmitting reliable information. In this paper,...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: Vehi...

A Vehicular Ad hoc NETwork (VANET) is a self-organized network, formed by vehicles and some fixed equipment on roads called Roads Side Units (RSUs). Vehicular communications are expected to share different kinds of information between vehicles and infrastructure. Because of these specifications, securing VANET constitutes a difficult and challengin...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: In V...

Global change and advancing technology have transformed the government sector with the use of information and communication technology to improve service delivery. The use of such technologies in electronic and mobile government services raises issues relating to security, privacy, and data protection. Security Frameworks in Contemporary Electroni...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mouhammad. ALLAH, may your blessings and peace be upon our Master Mouhammad and the family of our Master Mouhammad, the best blessings and peace. Abstract: V...

Vehicular Ad-hoc Networks (VANETs) allow communication among vehicles using some fixed equipment on roads. Vehicles share different kinds of information to improve road safety and provide travelers comfort using exchanged messages. However, falsified or modified messages can be propagated which affect the performance of the whole network and cause...

A vehicular ad hoc network (VANET) is a self-organized network that can be formed by connecting vehicles equipped with on-board units. Two types of communications are provided in VANET: vehicular-tovehicular and vehicular-to-infrastructure. In the first communication type, vehicles communicate directly, whereas in V2I, vehicles communicate through...

Because mobile ad hoc networks (MANETs) have neither infrastructure support nor central administration, they imply their nodes in the routing process. Having that this latter is fundamental in a MANET deployment, it constitutes a privileged target of attackers. For instance, malicious nodes can refuse to route packets or modify their content in ord...

VANET (Vehicular Ad hoc NETwork) is a self-organized network formed by connecting vehicles. It can be used in several cases such as internet connection to obtain real time news, traffic, and weather reports, etc. However, the main applications of VANET are oriented to safety issues (e.g., traffic services, alarm and warning messaging). In such cont...

I seek refuge with ALLAH from the accursed satan, In the name of ALLAH, and blessings and peace be upon the Messenger of ALLAH to all the worlds, our Master, the Messenger of ALLAH, Mohammad. ALLAH, may your blessings and peace be upon our Master Mohammad and the family of our Master Mohammad, the best blessings and peace. Abstract: In V...

Due to the lack of centralized administration or fixed network infrastructure, classic routing protocols cannot be applied in mobile ad hoc network (MANET). Hence, some specific ones have been proposed. Paradoxically, due to its importance in the MANET deployment, routing constitutes a privileged target of attackers. In addition, securing MANET con...

In a collaborative environment such as MANET, nodes reliability evaluation is vital. Trust Management can be used to ensure such healthy collaboration it offers a formal and unified framework for trust specification and interpretation. Establishing trustworthy relationships is generally done by maintaining a reputation for each node computed based...

A Mobile Ad-hoc Network (MANET) allows the communication of autonomous nodes without any preexistent network infrastructure. This main characteristic may introduce several vulnerabilities which can be exploited by malicious nodes. Thus, one of the basic requirements for the well behavior of such network is to detect and isolate such nodes. Recently...

MANETs (Mobile Ad hoc Networks) are described as sets of mobile nodes connected with wireless links. To be efficient, routing protocols in MANETs should, in fact, manage mobility, handle nodes energy dissipation and ensure security. We argue in this paper that trust negotiation is appropriate in such context to enhance the network performances. Tru...

Recently, we proposed a reputation based trust management scheme built upon a Mobility-based Clustering Approach (MCA) organizing Mobile Ad hoc Network MANET and detecting and isolating malicious behaviors. The whole scheme was called TMCA (Trust based MCA) and was extended in a second time with a delegation process resulting a proposition baptized...

n a collaborative environment such as MANET, nodes reliability evaluation is vital. Trust Management can be used to ensure such healthy collaboration it offers a formal and unified framework for trust specification and interpretation. Establishing trustworthy relationships is generally done by maintaining a reputation for each node computed based o...

A Distributed Denial of Service (DDoS) attack is used by malicious nodes in order to flood a victim node with large data flows. When the victim is a communication node, these attacks aim to damage network performances by reducing its resources such as bandwidth (bandwidth depletion attacks), computing power (processor depletion attacks) and energy...

MANETs (Mobile Ad hoc Networks) are self organized networks with mobile and collaborating nodes without any pre-established infrastructure. Because of these characteristics, securing MANETs constitute a hard and challenging task. Consequently, new mechanisms may be of interest to secure such networks. To this end, we have found that trust managemen...

Nations development depends heavily on the proper functioning of their Critical Infrastructures (CIs). Their security requirements are very important since small dysfunctions can deeply affect nation stability. We focus on their integrity need because Critical Information Infrastructures (CIIs) manipulate data that must be correct. The differentiat...

Ad hoc networks are very useful when it is difficult to deploy an infrastructure. In fact, Ad hoc Network is a collection of nodes having no fixed topology and co-operating with each other in order to route packets. This routing is made through special routing protocols. Paradoxically, these characteristics can be the cause of several security prob...

A Mobile Ad hoc NETwork (MANET) is a collection of mobile nodes having no fixed topology and cooperating with each other. Due to these particularities, classical routing protocols cannot be used and some specific ones have been proposed. Because routing process is fundamental in a MANET deployment, it constitutes a privileged target of attackers. I...

Security Policies (SP) constitute the core of communication networks protection infrastructures. It offers a set of rules allowing differentiating between legitimate actions and prohibited ones and consequently, associates each entity in the network with a set of permissions and privileges. Moreover, in today's technological society and to allow ap...

MANET (Mobile Ad hoc NETwork) is a self organized network with nodes collaborating in order to communicate. Hence, availability of the resources in such network is fundamental. Availability concerns essentially the network nodes as well as routing and forwarding actions accessibility. Generally, nodes lifetime is consumed by legitimate traffic. It...

A MANET is a collection of mobile nodes cooperating using low bandwidth wireless links. Its use is increasingly growing because it can be rapidly and easily deployed, and allows users to access and manipulate data anytime and anywhere. Because of these characteristics, classical routing protocols cannot be applied in such environment. To be efficie...

The importance of resources and services availability in Ad Hoc networks has already been proved several times in the past. It concerns, essentially, node availability as well as routing and forwarding actions accessibility. Unfortunately, nodes' lifetimes may be reduced or even depleted which leads to route failure, packets loss, QoS deterioration...

Trust is one of the fundamental security concepts since it provides network collaborating entities with a mean to counter their uncertainty. Trust is generally integrated into existent security frameworks in order to add a security level to entities collaborations through the use of trust relations. Besides, benefiting from trust relations implies...

A security policy constitutes one of the major actors in the protection of communication networks but can be one of their drawbacks too. This can be the case if it is inadequate to the security requirements for example. For this, a security policy has to be checked before its real deployment. In this paper, we propose three checking activities each...

XML became the de facto standard for the data representation and exchange on the internet. Regarding XML documents access control policy definition, OASIS ratified the XACML standard. It is a declarative language allowing the specification of authorizations as rules. Furthermore, it is common to formally represent XML documents as labeled trees and...

Because it governs all potential communication between entities, the need of security policies is nowadays increasingly growing and not to be any more proved. Moreover, in today's technological society and to allow applications perpetuity, communication networks must support the collaboration between entities to face up any unavailability or flinch...

Delegation is the process whereby a user can assign his authorizations to another user. This feature is necessary in today's communication networks principally because it allows the interaction between the entities composing such networks. This paper aims to give a first step toward a framework allowing to, formally, model delegation. Hence, we pro...

Security Policy constitutes the main basis of a secured system but can be its main vulnerability also since a wrongly configured policy or an inadequate one can be fatal for the system. Even if the network administrator is a high qualified person, the human interventions are error prone. Nevertheless, a formal specification can avoid such problem....

Security Policies constitute the core of network protection infrastructures. However, their development is a sensitive task because it can be in opposition with the security requirements (e.g. lack of rule or conflicting rules). A specification task seems to be indispensible in order to clarify the desired exigencies. A validation process for secur...

Security Policy specification and testing constitute two fundamental challenges in the development of secure communication systems since they can ensure that a security policy is correctly enforced. Model checking techniques can be used to do such task. Given a system modeling and a test criterion, the model checker can generate a counterexample fr...

In any organization, there are generally several applications in place and usually, each application has its own security policy. In fact, the ability to define multiple security policies is needed in several cases. Moreover, heterogeneous security mechanisms can be used to achieve security objectives. However, implementing a unified security polic...

Research in computer security issues has recently addressed the development of Security Policy specification languages. It has however omitted the need of formal validation. In this paper we try to remedy to this drawback by the proposition of an automated tool for security policies. Because we have found several similarities between security polic...

A security policy constitutes one of the major actors in the protection of communication networks. For this, and in order to manage the access grants in accordance with the security constraints, a security policy has to be validated before its deployment. Unfortunately, in the literature, there is no well established validation mechanisms ensuring...