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2015
Kotb, M. A., H. E. N. mahdy, N. E. - D. M. Khalifa, M. H. N. Taha, and M. A. Lotfi, "Pediatric Online Evidence-Based Medicine Assignment Is a Novel Effective Enjoyable Undergraduate Medical Teaching Tool: A SQUIRE Compliant Study", Medicine (Baltimore) Journal, vol. 94, issue 29, pp. 1178 - 1185, 2015. Abstractpediatric_online_evidence_based_medicine.13.pdfWebsite

Abstract: Evidence-based medicine (EBM) is delivered through a didactic, blended learning, and mixed models. Students are supposed to construct an answerable question in PICO (patient, intervention, comparison, and outcome) framework, acquire evidence through search of literature, appraise evidence, apply it to the clinical case scenario, and assess the evidence in relation to clinical context.

Yet these teaching models have limitations especially those related to group work, for example, handling uncooperative students, students who fail to contribute, students who domineer, students who have personal conflict, their impact upon progress of their groups, and inconsistent individual acquisition of required skills.

At Pediatrics Department, Faculty of Medicine, Cairo University, we designed a novel undergraduate pediatric EBM assignment online system to overcome shortcomings of previous didactic method and aimed to assess its effectiveness by prospective follow-up during academic years 2012 to 2013 and 2013 to 2014.

The novel web-based online interactive system was tailored to provide sequential single and group assignments for each student. Single assignment addressed a specific case scenario question, while group assignment was teamwork that addressed different questions of same case scenario. Assignment comprised scholar content and skills.

We objectively analyzed students’ performance by criterion-based assessment and subjectively by anonymous student questionnaire.

A total of 2879 were enrolled in 5th year Pediatrics Course consecutively, of them 2779 (96.5%) logged in and 2554 (88.7%) submitted their work. They were randomly assigned to 292 groups. A total of 2277 (89.15%) achieved ≥80% of total mark (4/5), of them 717 (28.1%) achieved a full mark. A total of 2178 (85.27%) and 2359 (92.36%) made evidence-based conclusions and recommendations in single and group assignment, respectively (P < 0.001). A total of 1102 (43.1%) answered student questionnaire, of them 898 (81.48%) found e-educational experience satisfactory, 175 (15.88%) disagreed, and 29 (2.6%) could not decide. A total of 964 (87.47%) found single assignment educational, 913 (82.84%) found group assignment educational, and 794 (72.3%) enjoyed it.

Web-based online interactive undergraduate EBM assignment was found effective in teaching medical students and assured individual student acquisition of concepts and skills of pediatric EMB. It was effective in mass education, data collection, and storage essential for system and student assessment.

Khalifa, N. E. - D. M., "A Security Scheme for Video Streaming in Wireless Multimedia Sensor Networks", Wireless Sensor Multimedia Networks Architectures, Protocols, and Applications, Florida, USA, CRC Press, 2015. Abstract

Wireless sensor networks (WSNs) have become an important component of our daily life. In the near future, they will dominate the technology industry around the world. WSNs have gained importance due to the variety of vital applications they can participate in, such as applications for the military, health care, agriculture, surveillance, and monitoring natural phenomena. Wireless multimedia sensor networks (WMSNs) are a special type of WSN.

2014
Khalifa, N. E. - D. M., Securing Real-Time Video Over IP Transmission: Comprehensive Study for Securing Real Time Multimedia Streaming, , Saarbrücken, Germany, LAP LAMBERT Academic Publishing, 2014. bookcovernour.jpgWebsite
2013
Mahmoud, N. E., M. H. N. Taha, H. E. N. mahdy, and I. A. Saroit, "A Secure Energy Efficient Schema for Wireless Multimedia Sensor Networks", CiiT International Journal of Wireless Communication, vol. 5, issue 6, pp. 235–246, 2013. AbstractA Secure Energy Efficient Schema for Wireless Multimedia Sensor Networks.pdf

Wireless Wireless Sensor Networks (WSNs) have become an important component in our daily lives. In near future, it will dominate the technology industry around the world. WSNs gain its importance due to the variety of vital applications it can participate in such as military, health care, agriculture, surveillance and monitoring natural phenomena applications.WSNs consist of small devices with limited energy and storage capabilities, called sensor nodes. The sensor nodes collect data from physical or environmental phenomena. They cooperatively pass the sensed data through the network to a certain location or sink node where the data can be collected and analyzed.Due to the unprotected nature of wireless communication channels and untrusted transmission medium of WSNs, it becomes vulnerable to many types of security attacks. The attackers ultimately seek to eavesdrop, steal confidential data, injecting false data or even jamming the whole network, so securing these networks becomes a must.In this paper, a proposed security schema for WSNs will be introduced. The proposed security schema will be appropriate for real time multimedia streaming. It will construct its security features within the application and transport layer as the information that the attackers seek ultimately exist within these layers.The proposed security schema consists of two security levels; the first level is encrypting the packet data using Advanced Encryption Standard (AES) while the second level is generating Message Authentication Code (MAC) using Cipher-based Message Authentication Code (CMAC). Both levels achieved the principles of WSNs security and they are (authentication, confidentiality, data integrity and availability).Performance comparisons between the proposed security schema and other security frameworks are presented. Finally, all the presented work in this research was developed and implemented using Network Simulator-2 (NS-2). According to our literature reviews, this research is one of the first researches that use NS-2 as a security simulator. As NS-2 does not support any security features before

2012
Mahmoud, N. E., M. H. N. Taha, H. N. Elmahdy, and I. A. Saroit, "A Secure Energy Mechanism for WSN and Its Implementation in NS-2", CiiT International Journal of Wireless Communication, vol. 4, issue 16, pp. 984–990, 2012. AbstractA Secure Energy Mechanism for WSN and Its Implementation in NS-2.pdf

Wireless sensor networks (WSNs) are usually deployed for gathering data from unattended or hostile environments. Therefore, securing data transmission across these environments is a must. Due to the fact that the sensors have a limited power, any security mechanism for sensor network must be energy efficient. In this paper, a secure energy efficient mechanism is introduced with a proposed scenario which leads to a significant improvement in network energy consumption. The mechanism constructs its security features in the application and transport layer as the information that the attackers seek ultimately resides within these layers. We modified the packet format for WSN. Data payload was encrypted by Advanced Encryption Standard (AES) and Message Authentication Code (MAC) was generated to assure data confidentiality and integrity. The energy consumption metric has been taken into considerations while designing and testing the mechanism to make it energy efficient as much as possible. The energy efficiency was achieved by giving a higher priority to the secured packet over the normal packet in the Interface Queue (IFQ). Through this paper, a detailed structure of the proposed mechanism is introduced and implemented using Network Simulator-2 (NS-2). This is the first research that implements security algorithms within NS-2. Since NS-2 does not support any security features before, this research will be a good start to begin using NS-2 as a security simulator.

2009
Khalifa, N. E. D. M., and H. E. N. mahdy, "The Impact of Frame Rate on Securing Real Time Transmission of Video over IP Networks", The IEEE International Conference on Networking and Media Convergence - ICNM'09, Cairo, Egypt, pp. 57-63, 2009. AbstractThe Impact of Frame Rate on Securing Real Time Transmission of Video over IP Networks.pdf

The nature of playing video streams over a network in a real time requires that the transmitted frames are sent in a bounded delay. Also, video frames need to be displayed at a certain rate; therefore, sending and receiving encrypted packets must be sent in a certain amount of time in order to utilize the admissible delay. There are two main components for securing multimedia transmissions. Key management protocols such as transport layer security (TLS) protocol is used as cryptographic protocol that provides security and data integrity for communications over IP networks. Advanced encryption standard (AES) is used as a symmetric block cipher, that can encrypt (encipher) and decrypt (decipher) video frames. The real-time transport protocol (RTP) protocol is used as a standardized packet format for delivering video over the IP Networks. This makes secure video encryption feasible for real-time applications without any extra dedicated hard-ware. In this paper; we studied the impact of frame rate on a secured real time transmission of video over IP networks. Through this paper, we will try to find the most suitable frame rate in order to achieve better data rate and fewer frame and packet loss. This is done via java as a programming language for implementation.

Mahmoud, N. E., Securing Real-Time Video over IP Transmission, , Giza, Cairo, Cairo University, 2009. Abstract

The world has become a small village. The internet has played an important role in the communications revolution. It facilitates the management of institutions and organizations in many countries. Due to advances in using multimedia streaming (especially video), it becomes important to secure real time video transmission.
Securing video depends on many factors. The key two factors are: the complexity of encryption algorithm and time to break the encryption by hackers or competitors.
There are two main components for securing multimedia transmissions: security protocols and text encryption algorithms. Security protocols have been used to provide security and data integrity for communications over IP networks. Text encryption algorithms have been used for encrypting and decrypting video frames.
This thesis proposed a security scheme for streamed video frames over IP network. We used Datagram Transport Layer Security (DTLS) protocol. We applied the most four famous text encryption algorithms on video frames. These algorithms are Advanced Encryption Standard (AES), Data Encryption Standard (DES), Triple Data Encryption Standard (3DES) and Blowfish. They were used to determine the most suitable one to be selected to secure video frames. We compared our results with previous results on video frames encryption. We also modified the Real-time Transport Protocol (RTP) to adapt the proposed security scheme. RTP is used as a standardized packet format for delivering video over the IP networks. Our proposed scheme would be feasible for real time applications without any extra dedicated hardware.
After determining the most suitable encryption algorithm, we compared the proposed security scheme with normal video transmission scheme according to the following parameters: Frame Loss, Packet Loss and Data Rate. We evaluated the overheads of the proposed scheme. We also studied the impact of frame rate on securing real time video transmission over IP networks.
We used JAVA programming language to develop the proposed scheme. We found that the secured connection setup needed more time than normal one. The secured setup time is an offline process, so it does not affect the transmission of video frames in the real time. Using random generated keys for encryption process for every connection makes attacks harder to happen. The AES algorithm is considered the most suitable text encryption algorithm to be used in video, as it achieves less encryption time per frame. We found that the size of the overhead was very small compared to video original size.
Finally, we studied the impact of frame rate on securing real time video streaming. We determined the best frame rate needed to achieve fewer frame, packet loss and best quality on video.