Wazen Shbair

University of Luxembourg · Computer Science and Communications Research Unit

With the large increase in the adoption of blockchain technologies, their underlying peer-to-peer networks must also scale with the demand. In this context, previous works highlighted the importance of ensuring efficient and resilient communication for the underlying consensus and replication mechanisms. However , they were mainly focused on mainst...

The XRP Ledger is one of the oldest and most well-established blockchains, using a particular type of consensus mechanism that differs from the typical Proof of Work and Proof of Stake. The underlying p2p network uses flooding to disseminate certain types of messages during the consensus rounds, leading to performance and scalability issues. In thi...

Recent technologies such as inter-ledger payments, non-fungible tokens, and smart contracts are all fruited from the ongoing development of Distributed Ledger Technologies. The foreseen trend is that they will play an increasingly visible role in daily life, which will have to be backed by appropriate operational resources. For example, due to incr...

With the growing adoption of Distributed Ledger Technologies and the subsequent scaling of these networks, there is an inherent need for efficient and resilient communication used by the underlying consensus and replication mechanisms. While resilient and efficient communication is one of the main pillars of an efficient blockchain network as a who...

PayString is an initiative to make payment identifiers global and human-readable, facilitating the exchange of payment information. However, the reference implementation lacks privacy and security features, making it possible for anyone to access the payment information as long as the PayString identifier is known. We propose an innovative solution...

The security of distributed applications backed by blockchain technology relies mainly on keeping the associated cryptographic keys (i.e. private keys) in well-protected storage. Since they are the unique proof of ownership of the underlying digital assets. If the keys are stolen or lost, there is no way to recover the assets. The cold wallet is a...

PayString is an initiative to make payment identifiers global and human-readable, facilitating the exchange of payment information. However, the reference implementation lacks privacy and security features, making it possible for anyone to access the payment information as long as the PayString identifier is known. We propose an innovative solution...

The security of distributed applications backed by blockchain technology relies mainly on keeping the associated cryptographic keys (i.e. private keys) in well-protected storage. Since they are the unique proof of ownership of the underlying digital assets. If the keys are stolen or lost, there is no way to recover the assets. The cold wallet is a...

Banks in Europe must comply with new EU regulation and legislation. Recent legislation has focused on personal data, Know Your Customer (KYC), and anti-money laundering. As a result, the cost of KYC compliance is higher than ever, requiring time consuming work by both the banks and their customers in the form of document collection and verification...

HTTPS is quickly rising alongside the need of Internet users to benefit from security and privacy when accessing the Web, and it becomes the predominant application protocol on the Internet. This migration towards a secure Web using HTTPS comes with important challenges related to the management of HTTPS traffic to guarantee basic network propertie...

Traffic monitoring is essential for network management tasks that ensure security and QoS. However, the continuous increase of HTTPS traffic undermines the effectiveness of current service-level monitoring that can only rely on unreliable parameters from the TLS handshake (X.509 certificate, SNI) or must decrypt the traffic. We propose a new machin...

Pretty Good Privacy (PGP) is one of the most prominent cryptographic standards offering end-to-end encryption for email messages and other sensitive information exchange. PGP allows to verify the identity of the correspondent in information exchange as well as the information integrity. PGP implements asymmetric encryption with certificates shared...

Future blockchain applications are anticipated to serve millions of users. Thus the evaluation of new blockchain applications have to consider large-scale assessment of the technologies behind the scene. Most of current testing approaches have been done either on simulators or via local small blockchain networks. Hence, the performance in real worl...

Know Your Customer (KYC) processes performed by banks on their customers are redundant, cumbersome and costly. Therefore, a system is proposed to automate menial tasks and allow sharing of data related to KYC. A blockchain dictates the collaboration between different participants and several services are built around it to support the functionality...

Pretty Good Privacy (PGP) is one of the most prominent cryptographic standards, offering end-to-end encryption for email messages and other sensitive information. PGP allows to verify the identity of the correspondent in information exchange as well as the information integrity. It implements asymmetric encryption with certificates shared through a...

Large files cannot be efficiently stored on blockchains. On one hand side, the blockchain becomes bloated with data that has to be propagated within the blockchain network. On the other hand, since the blockchain is replicated on many nodes, a lot of storage space is required without serving an immediate purpose, especially if the node operator doe...

Conducting experiments to evaluate blockchain applications is a challenging task for developers, because there is a range of configuration parameters that control blockchain environments. Many public testnets (e.g. Rinkeby Ethereum) can be used for testing, however, we cannot adjust their parameters (e.g. Gas limit, Mining difficulty) to further th...

Traditional Public-Key Infrastructure (PKI) is Certificate Authority based (CA-based). Thus, the security of PKI is completely relying on the security of CAs' infrastructure. However, many recent breaches show that the CA's infrastructure can be compromised as well as exposed to operational errors, while the Log-based PKIs and Web of Trust (WoT) ap...

We developed a tool that facilitates nodes reservation, deployment and blockchain configuration over the Grid’5000 platform.

Performance Measurement of Private Blockchains

Blockchain an overview and research perspective

In this thesis, we provide a privacy preserving for monitoring HTTPS services. First, we first investigate a recent technique for HTTPS services monitoring that is based on the Server Name Indication (SNI) field of the TLS handshake. We show that this method has many weakness, which can be used to cheat monitoring solutions.To mitigate this issue,...

Surveys show that websites are more and more being served over HTTPS. On one side, HTTPS provides users with essential properties of security and privacy, but on the other side, it raises important challenges and issues for organizations, related to the security monitoring of encrypted traffic (filtering, anomaly detection, etc.). Existing HTTPS mo...

We make our HTTPS dataset is publicly available with full payloads, which is not the case with current public ones. We aim to contribute in solving the absence of reference datasets for HTTPS. The dataset contains full HTTPS raw PCAP files of crawling top 779 accessed HTTPS websites. The scan was made daily based, two times per day using Goolge Chr...

Recent surveys show that the proportion of encrypted web traffic is quickly increasing. On one side, it provides users with essential properties of security and privacy, but on the other side, it raises important challenges and issues for organizations, related to the security monitoring of encrypted traffic (filtering, anomaly detection, etc.). Th...

The development of TLS-based encrypted traffic comes with new challenges related to the management and security analysis of encrypted traffic. There is an essential need for new methods to investigate, with a proper level of identification, the increasing number of HTTPS traffic that may hold security breaches. In fact, although many approaches det...

HTTPS Traffic Classification

An Open and Flexible Architecture for Monitoring HTTPS Traffic

Encrypted Internet traffic is an essential element to enable security and privacy in the Internet. Surveys show that websites are more and more being served over HTTPS. They highlight an increase of 48\% of sites using TLS over the past year, justifying the tendency that the Web is going to be encrypted. This motivates the development of new tools...

In Palestine, 44.7% of the population is under 16 with literacy rate of 91.9% over all of the population. More than half of Palestinian youth own computers and have access to the Internet. With such prospect, ensuring information security and spreading awareness of it is one of the main challenges facing researchers on a national level. In this...

This paper presents a genetic algorithm based approach to the scheduling of electricity distribution. Gaza strip challenges shortage of electricity power. Electricity Distribution Company overcomes this shortage by dividing the cities into sub-regions and providing them with electricity power in alternating manner. But this approach suffer from a l...

The phenomenal growth of networked computers has fostered the deployment of many network applications such as command and control military communication, Email, web browsing, E-voting, and E-shopping. Many applications need ultra-secure protection. This problem can simply states as: “By the act of communicating, even if perfect confidentiality of t...

Traffic analysis is a security attack where an adversary observes the statistical pattern of network traffic to infer sensitive information. Statistical properties such as packets length and inter-arrival time provide valuable information about an application, user's activities, and an underlying system. On the other hand, traffic analysis is categ...