Walid Khedr

Dr. Walid Khedr

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

View All Publications
22 March 2023 in IEEE Access
Verified
Journal Article
Open access
WKWalid Khedr
Walid Khedr
AGAmeer El-Sayed Gouda
Ameer El-Sayed Gouda
EMEhab R. Mohamed Mohamed
Ehab R. Mohamed Mohamed
The absence of standards and the diverse nature of the Internet of Things (IoT) have made security and privacy concerns more acute. Attacks such as distributed denial of service (DDoS) are becoming increasingly widespread in IoT, and the need for ways to stop them is growing. The use of newly formed Software-Defined Networking (SDN) significantly lowers the computational burden on IoT network nodes and makes it possible to perform more security measurements. This paper proposes an SDN-based, four-module DDoS attack detection and mitigation framework for IoT networks called FMDADM. The proposed FMDADM framework comprises four main modules and five-tier architecture. The first module implements an early detection process based on the average drop rate (ADR) principle using a 32-packet window size. The second module uses a novel double-check mapping function (DCMF), that aids in earlier attack detection at the data plane level. The third module is an ML-based detection application comprising four phases: data preprocessing, feature extraction, training and testing, and classification. This module detects DDoS attacks using only seven features: two selected and five newly computed features. The last module introduces an attack mitigation process. We applied the proposed framework to three test cases: one single-node attack test case and two multi-node attack test cases, all with real IoT traffic generated and deployed in Mininet-IoT. The proposed FMDADM framework efficiently detects DDoS attacks at high and low rates, can discriminate between attack traffic and flash crowds, and protects both local and remote IoT nodes by preventing infection from propagating to the ISP level. The FMDADM outperformed most existing cutting-edge approaches across ten different evaluation criteria. According to the experimental results, FMDADM achieved the following accuracy, precision, F-measure, recall, specificity, negative predictive value, false positive rate, false detection rate, false negative rate, and average detection time benchmarks:- 99.79%, 99.43%, 99.77%, 99.79%, 99.95%, 00.21%, 00.91%, 00.23%, and 2.64 μs, respectively.

23 May 2020 in Symmetry
Verified
Journal Article
Open access
PDF file
Ahmad SalahAhmad Salah
Ahmad Salah
ESEman Selem Shalabi
Eman Selem Shalabi
WKWalid Khedr
Walid Khedr
Smartphones and mobile tablets play significant roles in daily life and have led to an increase in the number of users of this technology. The rising number of mobile device end-users has resulted in the generation of malware by hackers. Thus, mobile devices are becoming vulnerable to malware. Machine learning plays an important role in the detection of mobile malware applications. In this study, we focus on static analysis for Android malware detection. The ultimate goal of this research is to find out the symmetric features across the malware Android application to easily detect them. Many state-of-the-art methods focus on extracting asymmetric patterns of the category of features, e.g., application permissions to distinguish the malware application from the benign application. In this work, we propose a compromise by considering different types of static features and select the most important features that affect the detection process. These features represent the symmetric pattern to be used for the classification task. Inspired by TF-IDF, we propose a novel method of feature selection. Moreover, we propose a new method for merging the Android application URLs into a single feature called the URL_score. Several linear machine learning classifiers are utilized to evaluate the proposed method. The proposed methods significantly reduce the feature space, i.e., the symmetric pattern, of the Android application dataset and the memory size of the final model. In addition, the proposed model achieves the highest reported accuracy for the Drebin dataset to date. Based on the evaluation results, the linear support vector machine achieves an accuracy of 99%.

17 May 2019 in IEEE Access
Verified
Journal Article
Open access
WKWalid Khedr
Walid Khedr
HKHeba M. Khater
Heba M. Khater
EMEhab R. Mohamed
Ehab R. Mohamed
Public cloud storage is a fundamental cloud computing service. Currently, most owners of large data outsource their data to cloud storage services—even high-profile owners such as governments. However, public cloud storage services are not optimal for ensuring the possession and integrity of the outsourced data, a situation that has given rise to many proposed provable data possession check schemes (PDP). A PDP scheme allows data owners to efficiently, periodically and securely verify that a cloud storage provider possesses the outsourced data. Most of the currently available provable data possession check schemes make selective (i.e., probabilistic) checks using random data blocks to verify data integrity rather than checking the entire dataset. Therefore, these schemes are considered inadequate by critical infrastructure sectors that involve highly sensitive data (critical data). In this paper, a new and efficient deterministic data integrity check scheme called cryptographic-accumulator provable data possession (CAPDP) is proposed. CAPDP surpasses the common limitations exhibited by other currently proposed schemes. The underlying scheme of CAPDP is based on a modified RSA-based cryptographic accumulator that has the following advantages: i) it allows the data owner to perform an unlimited number of data integrity checks; ii) it supports data dynamics; iii) it is efficient in terms of communication, computation and storage costs for both the data owner and the cloud storage provider; iv) the verification operation in the proposed scheme is independent of the number of blocks being verified; v) it minimizes the burden and cost of the verification process on the data owner’s side, enabling verification to be performed even on low-power devices; and v) it prevents tag forgery, data deletion, replacement, and data leakage attacks and detects replay attacks. Moreover, the prototype implementation and experimental results show that the scheme is applicable in real-life applications.

17 August 2023 in Mathematics
Verified
Journal Article
Open access
PDF file
WKWalid Khedr
Walid Khedr
AGAmeer El-Sayed Gouda
Ameer El-Sayed Gouda
EMEhab R. Mohamed Mohamed
Ehab R. Mohamed Mohamed
Distributed Denial of Service (DDoS) and Address Resolution Protocol (ARP) attacks pose significant threats to the security of Software-Defined Internet of Things (SD-IoT) networks. The standard Software-Defined Networking (SDN) architecture faces challenges in effectively detecting, preventing, and mitigating these attacks due to its centralized control and limited intelligence. In this paper, we present P4-HLDMC, a novel collaborative secure framework that combines machine learning (ML), stateful P4, and a hierarchical logically distributed multi-controller architecture. P4-HLDMC overcomes the limitations of the standard SDN architecture, ensuring scalability, performance, and an efficient response to attacks. It comprises four modules: the multi-controller dedicated interface (MCDI) for real-time attack detection through a distributed alert channel (DAC), the MSMPF, a P4-enabled stateful multi-state matching pipeline function for analyzing IoT network traffic using nine state tables, the modified ensemble voting (MEV) algorithm with six classifiers for enhanced detection of anomalies in P4-extracted traffic patterns, and an attack mitigation process distributed among multiple controllers to effectively handle larger-scale attacks. We validate our framework using diverse test cases and real-world IoT network traffic datasets, demonstrating high detection rates, low false-alarm rates, low latency, and short detection times compared to existing methods. Our work introduces the first integrated framework combining ML, stateful P4, and SDN-based multi-controller architecture for DDoS and ARP detection in IoT networks.

26 April 2018 in Circuits, Systems, and Signal Processing
Verified
Journal Article
Closed access
PDF file
KHKhalid M. Hosny
Khalid M. Hosny
YKYasmeen M. Khedr
Yasmeen M. Khedr
WKWalid Khedr
Walid Khedr
EMEhab R. Mohamed Mohamed
Ehab R. Mohamed Mohamed

18 March 2025 in Information
Verified
Journal Article
Open access
PDF file
ESEman Selem Shalabi
Eman Selem Shalabi
WKWalid Khedr
Walid Khedr
EMEhab R. Mohamed Mohamed
Ehab R. Mohamed Mohamed
Ahmad SalahAhmad Salah
Ahmad Salah
Federated learning (FL) is a machine learning technique where clients exchange only local model updates with a central server that combines them to create a global model after local training. While FL offers privacy benefits through local training, privacy-preserving strategies are needed since model updates can leak training data information due to various attacks. To enhance privacy and attack robustness, techniques like homomorphic encryption (HE), Secure Multi-Party Computation (SMPC), and the Private Aggregation of Teacher Ensembles (PATE) can be combined with FL. Currently, no study has combined more than two privacy-preserving techniques with FL or comparatively analyzed their combinations. We conducted a comparative study of privacy-preserving techniques in FL, analyzing performance and security. We implemented FL using an artificial neural network (ANN) with a Malware Dataset from Kaggle for malware detection. To enhance privacy, we proposed models combining FL with the PATE, SMPC, and HE. All models were evaluated against poisoning attacks (targeted and untargeted), a backdoor attack, a model inversion attack, and a man in the middle attack. The combined models maintained performance while improving attack robustness. FL_SMPC, FL_CKKS, and FL_CKKS_SMPC improved both their performance and attack resistance. All the combined models outperformed the base FL model against the evaluated attacks. FL_PATE_CKKS_SMPC achieved the lowest backdoor attack success rate (0.0920). FL_CKKS_SMPC best resisted untargeted poisoning attacks (0.0010 success rate). FL_CKKS and FL_CKKS_SMPC best defended against targeted poisoning attacks (0.0020 success rate). FL_PATE_SMPC best resisted model inversion attacks (19.267 MSE). FL_PATE_CKKS_SMPC best defended against man in the middle attacks with the lowest degradation in accuracy (1.68%), precision (1.94%), recall (1.68%), and the F1-score (1.64%).