Blerim Rexha

Prof. Dr. Blerim Rexha

University of Prishtina “Hasan Prishtina”
orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 April 2023 in Computers
Verified
Journal Article
Open access
PDF file
ABAhmet Bucko
Ahmet Bucko
Kamer VishiKamer Vishi
Kamer Vishi
BKBujar Krasniqi
Bujar Krasniqi
Blerim RexhaBlerim Rexha
Blerim Rexha
The rapid growth of the web has transformed our daily lives and the need for secure user authentication and authorization has become a crucial aspect of web-based services. JSON Web Tokens (JWT), based on RFC 7519, are widely used as a standard for user authentication and authorization. However, these tokens do not store information about the user’s behavior history. To address this issue, this paper presents a solution to enhance the trustworthiness of user authentication in web applications based on their behavior history. The solution considers factors such as the number of password attempts, IP address consistency, and user agent type and assigns a weight or percentage to each. These weights are summed up and stored in the user’s account, and updated after each transaction. The proposed approach was implemented using the .NET framework, C# programming language, and PostgreSQL database. The results show that the proposed solution effectively increases the level of trust in user authentication. The paper concludes by highlighting the strengths and limitations of the proposed solution.

16 September 2021 in Applied Artificial Intelligence
Verified
Journal Article
Closed access
AMArbena Musa
Arbena Musa
Kamer VishiKamer Vishi
Kamer Vishi
Blerim RexhaBlerim Rexha
Blerim Rexha
Biometric authentication methods, representing the ”something you are” scheme, are considered the most secure approach for gaining access to protected resources. Recent attacks using Machine Learning techniques demand a serious systematic reevaluation of biometric authentication. This paper analyzes and presents the Fast Gradient Sign Method (FGSM) attack using face recognition for biometric authentication. Machine Learning techniques have been used to train and test the model, which can classify and identify different people’s faces and which will be used as a target for carrying out the attack. Furthermore, the case study will analyze the implementation of the FGSM and the level of performance reduction that the model will have by applying this method in attacking. The test results were performed with the change of parameters both in terms of training and attacking the model, thus showing the efficiency of applying the FGSM.

28 May 2022 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Vehbi NeziriVehbi Neziri
Vehbi Neziri
Isak ShabaniIsak Shabani
Isak Shabani
RDRamadan Dervishi
Ramadan Dervishi
Blerim RexhaBlerim Rexha
Blerim Rexha
Anonymity and privacy in the electoral process are mandatory features found in any democratic society, and many authors consider these fundamental civil liberties and rights. During the election process, every voter must be identified as eligible, but after casting a vote, the voter must stay anonymous, assuring voter and vote unlinkability. Voter anonymity and privacy are the most critical issues and challenges of almost all electronic voting systems. However, vote immutability must be assured as well, which is a problem in many new democracies, and Blockchain as a distributed technology meets this data immutability requirement. Our paper analyzes current solutions in Blockchain and proposes a new approach through the combination of two different Blockchains to achieve privacy and anonymity. The first Blockchain will be used for key management, while the second will store anonymous votes. The encrypted vote is salted with a nonce, hashed, and finally digitally signed with the voter’s private key, and by mixing the timestamp of votes and shuffling the order of cast votes, the chances of linking the vote to the voter will be reduced. Adopting this approach with Blockchain technology will significantly transform the current voting process by guaranteeing anonymity and privacy.

10 July 2022 in Journal of Applied Security Research
Verified
Journal Article
Closed access
RTRrezearta Thaqi
Rrezearta Thaqi
Kamer VishiKamer Vishi
Kamer Vishi
Blerim RexhaBlerim Rexha
Blerim Rexha
Today’s web represents the most extensive engineered system ever created by humankind. Web security is critical to web application providers and end-users. Burp Suite is established as a state-of-the-art and fully featured set of tools for web vulnerability scanners. This paper presents a novel approach using state of the art Machine Learning algorithms applied to the Burp Suite extension. These algorithms were used to scan for: SQL injection, Cross-Site Request Forgery, and XML External Entity vulnerabilities in university web applications. The results show that the best algorithm is Long Short-Term Memory and that the targeted website is safe to use.

5 February 2018 in Future Internet
Verified
Journal Article
Open access
PDF file
Blerim RexhaBlerim Rexha
Blerim Rexha
GSGresa Shala
Gresa Shala
VXValon Xhafa
Valon Xhafa
Personal mobile devices currently have access to a significant portion of their user’s private sensitive data and are increasingly used for processing mobile payments. Consequently, securing access to these mobile devices is a requirement for securing access to the sensitive data and potentially costly services. Face authentication is one of the promising biometrics-based user authentication mechanisms that has been widely available in this era of mobile computing. With a built-in camera capability on smartphones, tablets, and laptops, face authentication provides an attractive alternative of legacy passwords for its memory-less authentication process, which is so sophisticated that it can unlock the device faster than a fingerprint. Nevertheless, face authentication in the context of smartphones has proven to be vulnerable to attacks. In most current implementations, a sufficiently high-resolution face image displayed on another mobile device will be enough to circumvent security measures and bypass the authentication process. In order to prevent such bypass attacks, gesture recognition together with location is proposed to be additionally modeled. Gestures provide a faster and more convenient method of authentication compared to a complex password. The focus of this paper is to build a secure authentication system with face, location and gesture recognition as components. User gestures and location data are a sequence of time series; therefore, in this paper we propose to use unsupervised learning in the long short-term memory recurrent neural network to actively learn to recognize, group and discriminate user gestures and location. Moreover, a clustering-based technique is also implemented for recognizing gestures and location.

1 November 2015
Verified
Conference Paper
Closed access
Blerim RexhaBlerim Rexha
Blerim Rexha
AHArbnor Halili
Arbnor Halili
KRKorab Rrmoku
Korab Rrmoku
DIDren Imeraj
Dren Imeraj
Nowadays all organizations tend to shift their daily business processes into web. This shifting requires from web developer's detailed knowledge about security techniques, such as Structured Query Language (SQL) injection and Cross Site Scripting Attack (XSS), otherwise the data managed and protected by web application could be exposed to not authorized parties. This paper aims to link and measure the impact of security techniques used by web developers for avoiding the vulnerabilities in web applications. We conducted a survey about the level of applicability of security techniques during web development and conducted a penetration testing for more than 110 local web sites. We discovered many vulnerabilities in these web sites and we linked the results with survey outcome.