Safwat Hamad

Mapping Distributed Object-Oriented Software to Architecture with Limited Number of Processors

Over the last few years, designers and engineers utilized the Object-Oriented (OO) approach in developing distributed software systems. One of the most important aspects of the Distributed Object Oriented (DOO) systems is the efficient distribution of software classes among different nodes. The initial design of the DOO application does not necessarily have the best class distribution and may need to be restructured. Previous restructuring techniques have not been considered DOO software. Within the context of DOO systems, it is a challenge to perform class restructuring due to the complexity of interactions between objects. In this paper, we propose a new methodology for efficiently restructuring the DOO software classes on a set of nodes in a distributed system. The proposed methodology consists of two phases. The first phase is partitioning the OO system into subsystems that have low coupling and are more suitable for distribution using a recursive graph bi-partitioning algorithm. The second phase is accomplished by mapping the generated subsystems to a set of available machines in the target distributed architecture. The results obtained from the simulated experiments approved that our approaches outperforms the traditional K-Partitioning algorithm.

Quantum secret sharing with identity authentication based on Bell states

Quantum secret sharing techniques allow two parties or more to securely share a key, while the same number of parties or less can efficiently deduce the secret key. In this paper, we propose an authenticated quantum secret sharing protocol, where a quantum dialogue protocol is adopted to authenticate the identity of the parties. The participants simultaneously authenticate the identity of each other based on parts of a prior shared key. Moreover, the whole prior shared key can be reused for deducing the secret data. Although the proposed scheme does not significantly improve the efficiency performance, it is more secure compared to some existing quantum secret sharing scheme due to the identity authentication process. In addition, the proposed scheme can stand against participant attack, man-in-the-middle attack, impersonation attack, Trojan-horse attack as well as information leaks.

A Double K-Clustering Approach for restructuring Distributed Object-Oriented software

There have been a large number of projects based on the Distributed Object Oriented (DOO) approach for solving complex problems in various scientific fields. The Mismatch problem is one of the most important problems facing the DOO system, where the initial design of the DOO application does not give the best class distribution. In such a case, the DOO software may need to be restructured. In this paper, we propose a methodology for efficiently restructuring the DOO software classes to be mapped on a distributed system consisting of a set of nodes. The proposed methodology consists of two phases. The first phase introduces a recursive graph clustering technique to partition the OO system into subsystems with low coupling. The second phase is concerned with mapping the generated partitions to the set of available machines in the target distributed architecture. A simulation evaluation was carried out for a set of randomly generated DOO software designs. Then the results were compared with those of the K-Partitioning algorithm in terms of the overall inter-class communication cost.

Authenticated quantum secret sharing with quantum dialogue based on Bell states

This work proposes a scheme that combines the advantages of a quantum secret sharing procedure and quantum dialogue. The proposed scheme enables the participants to simultaneously make mutual identity authentications, in a simulated scenario where the boss, Alice, shares a secret with her two agents Bob and Charlie. The secret is protected by checking photons to keep untrustworthy agents and outer attacks from getting useful information. Before the two agents cooperate to recover Alices secret, they must authenticate their identity using parts of a pre-shared key. In addition, the whole pre-shared key is reused as part of recovering the secret data to avoid any leaks of information. In comparison with previous schemes, the proposed method can efficiently detect eavesdropping and it is free from information leaks. Furthermore, the proposed scheme proved to be secure against man-in-the-middle attacks, impersonation attacks, entangled-and-measure attacks, participant attacks, modification attacks and Trojan-horse attacks.

DNA Watermarking Using Codon Postfix Technique

DNA watermarking is a data hiding technique that aims to protect the copyright of DNA sequences and ensures the security of private genetic information. In this paper, we proposed a novel DNA watermarking technique that can be used to embed binary bits into real DNA sequences. The proposed technique mutates the codon postfix according to the embedded bit. Our method was tested for a sample set of DNA sequences and the extracted bits showed robustness against mutation. Furthermore, the proposed DNA watermarking method proved to be secured, undetectable, resistance, and preservative to biological functions.

Towards a Friendly User Interface on the Cloud

The wide availability of high interconnection networks, powerful mobile devices and service-oriented architectures has paved the way for the delivery of cloud services. Moving information technology services to the cloud has imposed new ways of interaction with users. Users desire friendly looking, highly interactive, dynamically visualized and naturally controlled user interfaces (UI) that allow smooth navigation in the cloud space. Transferring the rich user interface of the desktop, where running the software dynamically online and instantly following up with social networking activities is relatively easy, to the web-browser on mobile devices is introducing many challenges. This has resulted in the emergence of innovative cloud services and implementation approaches specifically to handle the new user interface demands. However, a standardized consistent user interface metaphor for cloud services is still lacking. This paper presents a comprehensive study on the cloud user interface requirements, special services, implementation trends, technologies and efforts for standardization.

A Performance-Driven Approach for Restructuring Distributed Object-Oriented Software

Object oriented techniques make applications substantially easier to build by providing a high-level platform for appli-cation development. There have been a large number of projects based on the Distributed Object Oriented approach for solving complex problems in various scientific fields. One important aspect of Distributed Object Oriented systems is the efficient distribution of software classes among different processors. The initial design of the Distributed Object Oriented application does not necessarily have the best class distribution and may require to be restructured. In this paper, we propose a methodology for efficiently restructuring the Distributed Object Oriented software systems to get better performance. We use Distributed Object-Oriented performance (DOOP) model as guidance for our restructuring methodology. The proposed methodology consists of two phases. The first phase introduces a recursive graph clustering technique to partition the OO system into subsystems with low coupling. The second phase is concerned with mapping the generated partitions to the set of available machines in the target distributed architecture.

Improving the security of quantum key agreement protocols with single photon in both polarization and spatial-mode degrees of freedom

Quantum key agreement enables remote users to fairly establish a secure shared key based on their private inputs. In the circular-type multiparty quantum key agreement protocol, two or more malicious participants can collude together to steal the private inputs of honest participants or to generate the final key alone. In this paper, we focus on a powerful collusive attack strategy in which two malicious participants in particular positions, can learn sensitive information or generate the final key alone without revealing their malicious behavior. Most of the proposed circular-type multiparty quantum key agreement protocols are not secure against this particular collusive attack strategy. As an example, we analyze the security of a recently proposed multiparty key agreement protocol to show the vulnerability of existing circular-type multiparty quantum key agreement protocols against this collusive attack. We then design a general secure multiparty key agreement model that would remove this vulnerability from such circular-type key agreement protocols and describe the necessary steps to implement this model. Our model is general and does not depend on the specific physical implementation of quantum key agreement.Recently, Wang and Ma (Quantum Inf Process 16(5):130, 2017) proposed two interesting quantum key agreement protocols with a single photon in both polarization and spatial-mode degrees of freedom. They claimed that the privacy of participants’ secret keys in the multiparty case is protected against dishonest participants. However, in this paper, we prove that two dishonest participants can deduce the secret key of an honest one using a fake sequence of single photons, without being detected. Also, we propose an additional security detection process to avoid the security loophole in their protocol.

Coronary Artery Vessel Tree Enhancement in Three-Dimensional Computed Tomography Angiography

Coronary artery segmentation in 3D images is a fundamental step in evaluating the degree of Coronary Artery Disease (CAD) in cardiac clinical diagnosis and surgical planning. In this paper, we study the effect of vessel filtering and enhancement on coronary artery segmentation from Computed Tomography Angiography (CTA) datasets. The method mainly consists of two steps: (1) CTA datasets enhancement using Hessian-based analysis; and (2) coronary vessels segmentation in enhanced images using Otsu thresholding. The experiments are carried on 18 different CTA datasets and segmentation results of enhanced and non-enhanced datasets are quantitatively measured and compared using three different evaluation metrics. Experimental results show that segmenting coronary vessels in enhanced CTA images gives more accurate extraction of coronary arteries than non-enhanced images.

Automatically Seeded Region Growing Approach for Automatic Segmentation of Ascending Aorta

Region Growing is frequently used for segmentation purposes especially for objects with homogenous intensity. The problem is how the region growing approach begins, how it proceeds and how it finally ends. In this paper we present a modified region growing approach for the purpose of automatic segmentation of the ascending aorta from Computed Tomography Angiography (CTA) images. The ascending aorta in CTA images has homogenous intensity which makes region growing a good approach for its segmentation. Moreover the approach presented in this paper is fully automatic to suit clinical non-invasive diagnosis purposes. For developing our region growing approach; the geometric, spatial and intensity features of the ascending aorta has been exploited. These features provide the region growing methodology with the automatic seed from which it begins and then continues to segment the whole ascending aorta from the aortic arch down to ostia points. The proposed algorithm is tested and validated on the Computed Tomography Angiography database provided by the Rotterdam Coronary Artery Algorithm Evaluation Framework. The proposed algorithm has three main advantages: 1) its fully automatic, i.e. no user interaction needed, 2) real-time performance even with large datasets, 3) robust since parameters values are the same for all the tested datasets.