Showing papers by "Robin Doss published in 2018"

Routing protocols in opportunistic networks – a survey

Abstract: Opportunistic networks (OppNets) refer to a number of wireless nodes opportunistically communicating with each other in a form of “Store–Carry–Forward”. This occurs when they come into contact with each other without a proper network infrastructure. OppNets are designed to operate in an environment characterized by high delay, high error rate, intermittent connectivity, and non-availability of end-to-end route between the source and destination. OppNets use wireless technologies, such as IEEE 802.11, WiMAX, Bluetooth, and other short-range radio communication, and grow from a single node (seed) to become large networks by inviting new nodes (helpers) to join the network. Nodes have the ability to store and carry data and also forward it to other nodes in order to achieve different tasks. In OppNets, there is no end-to-end connection between the source and the destination nodes. Further, due to their inherent features, OppNets suffer from frequent partitions and long delays, while also being subjec...

A Scalable and Efficient PKI Based Authentication Protocol for VANETs

Abstract: Intelligent Transportation System (ITS) has came up as important solution for safety of automotive users. ITS deployment in near future will not only improve drivers and passengers safety but also will reduce road safety and traffic congestion problems by providing information to its users. The vehicles will be capable of communicating with other vehicles as well as with road side infrastructure to form self-organizing vehicular ad hoc networks (VANETs). VANETs as core part of ITS enables transfer of data among the entities of ITS. This data consists of private information of VANETs users such as exact location. Therefore, authentication of users is mandatory to restrict access of this information by any malicious user or attacker. PKI based authentication is considered as a feasible scheme for VANETs. However, enormously sized Certificate Revocation List (CRL) adds extra delay in process of authenticating requests. This makes users unable to acquire services timely and obstructs the scalability of VANETs. In this paper, we propose a protocol which makes CRL size linear and authentication process efficient. We perform simulations to show the reduced authentication delay for wide range of authentication requests.

Mapping Functions Driven Robust Retinal Vessel Segmentation via Training Patches

Abstract: Vein occlusions and diabetic retinopathy are two of many retinal pathologies affecting the retina Understanding robust vessel segmentation of fundus images is of vital importance for improving the diagnosis results of these diseases This paper proposes a novel approach for computing the minimum distance for each test patch via the distance comparison within the test patch and cluster centers The numerous patches are calculated using manual segmentations through the K-means algorithm We demonstrate the efficiency of learning the simple pattern from each cluster; meanwhile, the mapping function for each cluster is determined by the patches in the training images and their corresponding manual segmentation patches Two publicly recognized benchmark data sets, namely DRIVE and STARE, are used in our experimental validation Experimental results show that the proposed approach outperforms conventional methods for vessel segmentation problems validated via public benchmark data sets, ie, DRIVE and STARE

Identifying Drawbacks in Malicious PDF Detectors

Abstract: Despite the continuous countermeasuring efforts, embedding malware in PDF documents and using it as a malware distribution mechanism is still a threat. This is due to its popularity as a document exchange format, the lack of user awareness of its dangers, as well as its ability to carry and execute malware. Several malicious PDF detection tools have been proposed by the academic community to address the PDF threat. All of which suffer some drawbacks that limit its utility. In this paper, we present the drawbacks of the current state of the art malicious PDF detectors. This was achieved by undertaking a survey of all recent malicious PDF detectors, followed by a comparative evaluation of the available tools. Our results show that Concept drifts is major drawback to the detectors, despite the fact that many detectors use machine learning approaches.

A Literature Review of Inter-enterprise SOA in Small and Medium Business Communities

Abstract: The service-oriented architecture (SOA) enables organizations to cooperate in expanding their businesses and creating new opportunities by connecting multiple participant’s resources. However, some organizations are not yet ready to integrate with this inter-enterprise SOA environment due to their internal traditional IT-based systems. So, to face the challenge of market and system expansion, they first have to enable their systems for collaboration. This paper explores and analyses SOA implementation aspects in the small and medium enterprise (SME) communities by using systematic literature review method. This work presents facts regarding the state of SME community, i.e. the attributes, existing IT architectures, and the adopted collaboration frameworks. Virtual organization (VO) with its variants is a prominent model to establish in the ICT-based SME community. The centralized system is the dominant architectural structure types proposed due to the natural characteristics of SOA and SMEs.

Metamodel for Artefacts in Service Engineering Analysis and Design

Abstract: As a process of developing a service system, the term ‘service engineering’ evolves in scope and definition. To achieve an integrated understanding of the process, a general framework and an ontology are required. This paper extends a previously built service engineering framework by exploring metamodels for the framework artefacts based on a foundational ontology and a metamodel landscape. The first part of this paper presents a correlation map between the proposed framework with the ontology as a form of evaluation for the conceptual coverage of the framework. The mapping also serves to characterize the artefacts to be produced for each activity in the framework. The second part describes potential metamodels to be used, from the metamodel landscape, as alternative formats of the framework artefacts. The results suggest that the framework sufficiently covers the ontological concepts, both from general service context and software service context. The metamodel exploration enriches the suggested artefact format from the original eighteen formats to thirty metamodel alternatives. Keywords—Artefact, framework, service, metamodel.

Trust strategy implementation in OppNets

Abstract: With the natural characteristics of Opportunistic networks (OppNets) where delivery is delayed with frequent disconnections between mobile nodes in dynamically changing routes to destinations, malicious nodes can perform selective packet dropping attacks easily without been identified easily. This is why securing the data flow without any loss becomes challenging in OppNets. In this paper, we present a solid trust based node and path detection technique against selective packet dropping attacks. Using the trust attribute with the Merkle hashing technique, a node’s identity can be validated, and malicious nodes can be detected. We integrate our proposed technique with Epidemic routing and use simulation to show how effective the technique works against selective packet dropping attacks. We use simulation to show how the node detection accuracy increases with time, as intermediate nodes have more time to establish trust with destination nodes. We also use simulation to show that delivery rates increase with increased storage, and show how our trust model improves and secures routing compared to non-trust models.

A New Method for Sharing the Public Keys in Opportunistic Networks

Abstract: Opportunistic Networks do not have a fundamental infrastructure, and different nodes in these networks have the role of a sender, receiver and a router. Intermediate nodes should route messages to neighbors and they should extract sufficient information for this purpose while the content of the message is still hidden. In order to achieve this aim, messages should be encrypted. While there is not a constant path between two specific nodes in OppNet, it is not possible to use traditional solutions such as a trusted third party for sharing the public key. In this paper, a new confidentiality structure is proposed in order to encrypt the messages and sharing nodes’ public key in Opportunistic Networks. By this new structure, intermediate nodes may route messages while they are not able to extract payload of a message.

A Novel Approach for Information Discovery in Wireless Sensor Grids

Abstract: Multi-dimensional Wireless sensor grids (WSG)s are deployed in complex environments to sense and collect data relating to multiple attributes (multi-dimensional data). Such networks present unique challenges to data dissemination, data storage of in-network information discovery. However, in order to fully exploit these networks for mission-critical applications, energy-efficient and scalable solutions for information discovery are essential. In this paper, we propose a novel and adaptive method for information discovery for multi-dimensional WSGs that can significantly increase network lifetime and minimize query processing latency, resulting in quality of service improvements that are of immense benefit to mission-critical applications. Further, we investigate efficient strategies for information discovery in large-scale wireless sensor networks and propose the Adaptive Multi-Dimensional Multi-Resolution Architecture (A-MDMRA) that efficiently combines “push” and “pull” strategies for information discovery. The A-MDMRA also adapts to variations in the frequencies of events and queries in the network to construct optimal routing structures. We present simulation results to show that the proposed approach to information discovery offers significant improvements on query resolution latency compared with current approaches. We observe that our proposed methods outperform existing schemes such as double rulings, comb needle and Time-Parameterized Data Centric Storage by up to 14% in terms of query resolution latency and up to 20% in terms of energy-efficiency.

Consolidating Service Engineering Ontologies : Building Service Ontology from SOA Modeling Language (SoaML)

Abstract: As a term for characterizing a process of devising a service system, the term ‘service engineering’ is still regarded as an ‘open’ research challenge due to unspecified details and conflicting perspectives. This paper presents consolidated service engineering ontologies in collecting, specifying and defining relationship between components pertinent within the context of service engineering. The ontologies are built by way of literature surveys from the collected conceptual works by collating various concepts into an integrated ontology. Two ontologies are produced: general service ontology and software service ontology. The software-service ontology is drawn from the informatics domain, while the generalized ontology of a service system is built from both a business management and the information system perspective. The produced ontologies are verified by exercising conceptual operationalization of the ontologies in adopting several service orientation features and service system patterns. The proposed ontologies are demonstrated to be sufficient to serve as a basis for a service engineering framework.