Computer Science & Engineering

In recent times, the popularity of group oriented applications such as electronic conferences and collaboration works have increased manifold. Security is crucial for such collaborative applications which operate in a dynamic network environment and communicate over insecure networks such as internet. The design of secure conference key establishment protocol is essential to provide security to such group applications. Most security protocols currently available in the literature are not fully applicable to wireless environment involving low power mobile devices. Few protocols that have been proposed for wireless environment also lack important security properties and formal proof. One such important property is truly contributory key agreement that has not been addressed previously. In this work we propose a new conference key agreement protocol for mobile environment which addresses the truly contributory property and assures users about their participation in the key computation. The design of the protocol is based on polynomial interpolation. We demonstrate that the protocol is provably secure against active adversaries. The performance analysis of the proposed protocol shows that its well suited for mobile environment.

Secure group communication in heterogeneous environment is gaining popularity due to the advent of wireless and ubiquitous computing. Although a number of protocols for group key agreement have been proposed, most of them are not applicable in heterogeneous environment where a number of computationally limited nodes coexist with one or more computationally efficient nodes. Among the few existing protocols, where some fail to satisfy the key agreement properties, some are unable to handle the agreement for dynamic group. In this work, we propose a constant round group key agreement protocol for heterogeneous environment using polynomial interpolation. The protocol ensures both communication and computation efficiency by shifting the major computation load on powerful users, achieves true contributory key agreement property and dynamic handling of user join and leave. The security of the protocol has been analyzed under formal model. Finally we have extended the protocol to hierarchy, offering more scalability without affecting the security and efficiency. The comparison result shows considerable improvement in protocol efficiency compared to the existing ones.

In this work, we have proposed a new token based Fairness Algorithm for Priority Processes (FAPP) that addresses both the issues and keeps the control message traffic reasonably low. One major limitation of the token based mutual exclusion algorithms for distributed environment like Raymond's well-known work on invertedtree topology lies in the lack of fairness. Another aspect of the problem is in handling the prioritized processes. In one of our earlier works, both fairness and priority have been addressed in proposing an algorithm MRA-P. However, MRA-P suffered from some major shortcomings like lack of liveness, high message complexity, etc. The proposed FAPP algorithm, in spite of considering priority of processes, ensures liveness in terms of token requests from low priority processes. Formal verification on FAPP justify properties like correctness of the algorithm, low message complexity, and fairness in token allocation.

Cloud Computing offers a computing model for the organizations to implement the functions related to Information technology with lower Total Cost of Ownership and without investment. Cloud Computing opens door for multiple, unlimited venues from elastic computing to demand provisioning for dynamic storage and computing. Besides the gains of the cloud computing, the security and accessing the resources freely is a big problem which affects the cloud adoption. Security problem is related with the multi-tenancy, elasticity, architecture, layer dependency. This paper gives a detailed analysis about the problems related to the security of the cloud such as characteristic perspective, stakeholder perspective, architecture perspective, delivery model perspective. Also this paper analysis about challenges regarding the research by implementing cloud security solutions which secures the changing and dynamic model of the cloud. Based on these analysis a detailed derived specifications of the problem related to cloud security, key features must be covered by the proposed security solutions for the cloud computing.

Data Warehouse is one of the most common ways for analyzing large data for decision based system. These data are often sourced from online transactional system. The transactional data are represented in different formats. XML is one of the worldwide standards to represent data in web based system. Numbers of organizations use XML for e-commerce and internet based applications. Integration of XML and data warehouse for the innovation of business logic and to enhance decision making has therefore emerged as a demanding area of research interest. This paper focuses on integrating XML data based on multiple related XML schemas, to an equivalent data warehouse schemas based on relational online analytical processing (ROLAP). This work bears a high relevance towards standardizing of the ETL phase (Extraction, Transformation, and Loading) of the OLAP projects. The novelty of the work is that more than one data warehouse schemas could be identified from a single related XML schema and each of them could be categorized as star schema or snowflake schema. Moreover if the individual schemas are found to be related according to the analysis, fact constellation could be identified. A new data structure, Schema Graph has been proposed in the process.

Completely GPS-free positioning systems for wireless, mobile, ad-hoc networks typically stress on building a network-wide coordinate system. Such systems suffer from lack of mobility and high computational overhead. On the other hand, specialized hardware in GPS-enabled nodes tends to increase the solution cost. A number of GPS free position based routing algorithms have been studied by the authors before proposing a new positioning framework in this paper. The proposed positioning framework is characterized by using only a handful of GPS enabled nodes. Lower dependence on specialized GPS hardware reduces the total cost of implementing the framework. A new location aided routing protocol called Location Aided Cluster Based Energy-efficient Routing (LACBER) has been proposed in the paper. Simulation results show that using the proposed positioning framework, LACBER turns out to be efficient in lowering mean hop and hence in utilizing the limited energy of mobile nodes.

Abstract: Cloud Computing holds the potential to eliminate the requirements for setting up of high-cost computing infrastructure for the IT-based solutions and services that the industry uses. It promises to provide a flexible IT architecture, accessible through internet for lightweight portable devices. This would allow many-fold increase in the capacity or capabilities of the existing and new software. In a cloud computing environment, the entire data reside over a set of networked resources, enabling the data to be accessed through ...

Abstract: Cloud Computing holds the potential to eliminate the requirements for setting up of high-cost computing infrastructure for the IT-based solutions and services that the industry uses. It promises to provide a flexible IT architecture, accessible through internet for lightweight portable devices. This would allow many-fold increase in the capacity or capabilities of the existing and new software. In a cloud computing environment, the entire data reside over a set of networked resources, enabling the data to be accessed through ...

Mobile Ad Hoc Network (MANET) is a dynamic multihop wireless network which is established by a set of mobile nodes on a shared wireless channel. One of the major issues in MANET is routing due to the mobility of the nodes. Routing means the act of moving information across an internet work from a source to a destination. When it comes to MANET, the complexity increases due to various characteristics like dynamic topology, time varying QoS requirements, limited resources and energy etc. QoS routing plays an important role for providing QoS in wireless ad hoc networks. The biggest challenge in this kind of networks is to find a path between the communication end points satisfying user's QoS requirement. Nature-inspired algorithms (swarm intelligence) such as ant colony optimization (ACO) algorithms have shown to be a good technique for developing routing algorithms for MANETs. In this paper, a new QoS algorithm for mobile ad hoc network has been proposed. The proposed algorithm combines the idea of Ant Colony Optimization (ACO) with Optimized Link State Routing (OLSR) protocol to identify multiple stable paths between source and destination nodes.

The focus of this papere is to present an intuitive enduser Decision Support System (DSS) for portfolio selection based on Mean-Variance (M-V) Model of portfolio selection by Markowitz [1952, 1991]. The DSS utilizes a Goal Linear Programming (GLP) model for fulfiling the investor's objectives and preferences in terms rate of return, risk and asset allocation and diversification in order to reach an optimum solution. The DSS reported is flexiable enough and could be extended through goal extension, extending the goal achievement requirements by adding more goals and using other models within the computation intelligence paradigm such ANN, Fuzzy, Rough Sets, Genetic Algorithm (GA), etc. The DSS is implement within an objective-oriented paradigm using Microsoft VB.NET.

Completely GPS-free positioning systems for wireless, mobile, ad-hoc networks typically stress on building a network-wide coordinate system. Such systems suffer from lack of mobility and high computational overhead. On the other hand, specialized hardware in GPS-enabled ...

In multi-hop wireless systems, the need for cooperation among nodes to relay each other's packets exposes them to a wide range of security attacks. A particularly devastating attack is the wormhole attack, where a malicious node records control traffic at one location and tunnels it to ...

The distributed command and control environment includes limited computer resources and numerous mission critical applications competing for these scarce resources. Additionally the stringent constraints and considerable complexity of distributed command & control ...

XML is a worldwide standard to represent data in web based system. Numbers of organizations use XML for e-commerce and internet based applications. On the other hand, data warehouse is used by most of the organizations for making decisions on their business by analyzing operational data. Integration of business logic based on data warehouse and XML based system has therefore emerged as a demanding area of research interest. This paper illustrates an approach to integrate XML data based on multiple related XML Schemas, to its compatible data warehouse schemas based on relational online analytical processing (ROLAP). The novelty of the work is that more than one type of data warehouse schemas could be identified from a single related XML schema. A new data structure, Schema Graph has been proposed in the process.

This paper presents a method for recognizing isolated spoken Bengali numerals. Noisy audio samples have been considered as input in this study. Mel frequency cepstral coefficients (MFCC) have been used for extraction of feature from the audio samples. Vector quantization is applied to reduce the dimension of the feature vectors and to generate a vector codebook for the numerals. The classification is based on the dynamic time warping (DTW) and a minimum distance classifier based on Euclidean distance measure. Both the speaker dependent and speaker independent situations have been considered for checking accuracy. Results show the limitations of MFCC based standard speech processing approach in speaker independent spoken digit recognition scenario in the presence of noise.

Internet of Things is a novel concept that semantically implies a worldwide network of uniquely addressable interconnected smart objects. It is aimed at establishing any paradigm in computing. This environment is one where the boundary between virtual and physical world is eliminated. As the network gets loaded with hitherto unknown applications, security threats also become rampant. Current security solutions fail as new threats appear to destruct the reliability of information. The network has to be transformed to IPv6 enabled network to address huge number of smart objects. Thus new addressing schemes come up with new attacks. Real time analysis of information from the heterogeneous smart objects needs use of cloud services. This can fall prey to cloud specific security threats. Therefore need arises for a review of security threats for a new area having huge demand. Here a study of security issues in this domain is briefly presented.

This paper presents a new logical topology SBS-net, a Scalable Barrel Shifter network to be used as a logical topology over an all-optical network using WDM. The major emphasis of the present work is to improve upon the scalability issue. This SBS-net connects any arbitrary numbers of nodes as opposed to the Barrel Shifter, de Bruijn graph and Shufflenet. The average hopping distance between two nodes using this topology is smaller compared to that in de Bruijn Graph, Shufflenet & GEM net.

Rapid development of smart technologies enables use of cloud service for large-scale data storage. Remote access of original data as well as biometric data from cloud storage enhances several challenges. It is inevitable to prevent unauthorized access of data stored in cloud. Biometrics authentication is more efficient than the known traditional authentication mechanisms. Authentication is a major security feature used to protect data privacy, whereas additional security features used to protect data may adversely affect it. There must be a balance between security and privacy during secure authentication design. Here a survey of security and privacy issues for biometrics based remote authentication in cloud is briefly presented and the research gaps are identified to attract more research on this domain in near future.

Data warehouse represents multi-dimensional data suitable for analytical processing and logically data are organized in the form of data cube or cuboid. Data warehouse actually represents a business theme which is called fact table. The cuboid that identifies the complete fact table is called base cuboid. The all possible combination of the cuboids that could be generated from base cuboid corresponds to lattice structure. A lattice consists of numbers of cuboids. In real life, all these cuboids may not be important for business analysis. Thus all of them are not always called during business processing. The cuboids that are referred in different applications are fetched from diverse memory hierarchy such as cache memory, primary memory and secondary memory. The different execution speed of the respective memory element is taken into account which forms a memory hierarchy. The focus of this research work is to dynamically identify the most cost effective path within the lattice structure of cuboids to minimize the query access time having the knowledge of existing cuboid location at different memory elements.

Occasional user influx in a cell in a public place like a football stadium congests the network and even leads towards total disruption of services. However, for this temporary high user concentration, the service providers would not be interested in maintaining a huge infrastructure. This demands an efficient, provisional capacity enhancement technique without any additional infrastructure towards increasing service accessibility to maximum number of users. In this paper, an attempt has been made to propose a light weight call admission algorithm for increasing the number of admitted call in this type of constrained scenario. The proposed algorithm is supposed to work satisfactory for a GSM standard telephone network in terms of adaptability, number of admitted customer and the involved cost overhead.