Distributed Computing and Internet Technology

We make the case for usable mobile security by outlining why usable security in mobile devices is important and why it is hard to achieve. We describe a number of current problems in mobile devices that need usable and secure solutions. Finally, we discuss the characteristics of mobile devices that can actually help in designing usable solutions to mobile security problems.

In this paper we propose

actor-networks

as a formal model of computation in heterogenous networks of computers, humans and their devices, where these new procedures run; and we introduce

Procedure Derivation Logic

(PDL) as a framework for reasoning about security in actor-networks, as an extension of our previous

Protocol Derivation Logic

. Both formalisms are geared towards graphic reasoning. We illustrate its workings by analysing a popular form of two-factor authentication.

Distributed and multi-agent systems come in many forms, serving various purposes and spanning a large variety of properties. They include networked processors communicating via message-passing, shared-memory systems in which processes interact by reading from and writing to shared variables, and even systems of robots that coordinate their actions by viewing each others’ actions and locations, and perform no explicit communication actions. While distinct systems may differ completely in their detailed structure and operation, fundamental to all distributed systems is the fact that decisions are performed based on a local, partial, view of the the state of the system. Proper coordination among different sites of such a system requires information flow among them, to ensure that decisions are taken based on appropriate knowledge. Reasoning about when elements of the system do or do not know relevant facts is therefore a central aspect of the design and construction of distributed systems and distributed protocols.

A key challenge in multi-robot teaming research is determining how to properly enable robots to make decisions on actions they should take to contribute to the overall system objective. This article discusses how many forms of decision making in multi-robot teams can be formulated as optimization problems. In particular, we examine the common multi-robot capabilities of task allocation, path planning, formation generation, and target tracking/observation, showing how each can be represented as optimization problems. Of course, globally optimal solutions to such formulations are not possible, as it is well-known that such problems are intractable. However, many researchers have successfully built solutions that are approximations to the global problems, which work well in practice. While we do not argue that all decision making in multi-robot systems should be based on optimization formulations, it is instructive to study when this technique is appropriate. Future development of new approximation algorithms to well-known global optimization problems can therefore have an important positive impact for many applications in multi-robot systems.

In the literature various two level interconnection networks are proposed using hypercubes or star graphs. In this paper, a new two level interconnection network topology called the Metastar denoted as Mstar(k,m) is introduced. The proposed network takes the star graph as basic building blocks. Here, the network at the lower level is a star but at the higher level the network is a cube. Its various topological parameters such as packing density, degree, diameter, cost, average distance and hamiltonicity are investigated. Message routing and broadcasting algorithms are also proposed. Performance analysis in terms of topological parameters is done and the proposed network is proved to be a suitable candidate for large scale computing.

Wireless Sensor Networks (WSN) consist of a large number of sensor nodes equipped with limited computational capacity, memory and battery energy. As sensor nodes in WSN deployed in a hostile and unattended environment, the networks is susceptible to various malicious threats. False data injection is one of them. An adversary may attempt to inject false data containing non-existent events through some compromised nodes causing false alarms at the base station and draining out energy of forwarding nodes. As a result, detection of false data injection in WSN is an important concern. This paper presents a scheme using hash-based short signatures for filtering false data injection in WSN.

In mobile adhoc networks, generating and maintaining anonymity for any adhoc node is challenging because of the node mobility, dynamic network topology, cooperative nature of the network and broadcast nature of the communication media. Anonymity is provided to protect the communication, by hiding the participants as well as the message contents. Existing techniques based on cryptosystem and broadcasting cannot be easily adapted to MANETs because of their extensive cryptographic computations and/or large communication overheads. In this paper, we first propose an unconditionally secure privacy preserving message authentication scheme (PPMAS) which uses Modified New variant ElGamal signature Scheme (MNES). This scheme enables a sender to transmit messages, providing authentication along with anonymity, without relying on any trusted third parties. The anonymous message uses privacy preserving communication protocol for MANET, which is capable of anonymous end to end connections. It also allows the untraceability of the link between the identifier of a node and its location. The experimental analysis of the proposed system is presented.

This paper proposes a distributed algorithm for circle formation by multiple autonomous mobile robots. The vision of each robot is limited to a maximum distance. The robots do not store past actions or records of past data. They are anonymous and cannot be distinguished by their appearances. All robots agree on a common origin and axes. Earlier works report algorithms for

gathering

of multiple autonomous mobile robots in limited visibility considering the robots to be dimensionless or points. This paper models a robot as a unit disc (

fat robot

). The algorithm presented in this paper also assures that there is no collision among the robots. The robots do not share a common clock. They execute the algorithm asynchronously.

OODBMS is widely favored for mapping domains like CAD, with complex representation requirements. The transactions accessing OODBMS can be categorized into runtime transactions and design time transactions. Runtime transactions are meant for accessing data and design time transactions are meant for accessing schema. Parallel execution of transactions is supported to promote concurrency and throughput. In continuously evolving business domains, frequent schema changes are done to reflect the changes of business domain. Then it implies that more number of design time transactions arrive parallely with runtime transactions. Concurrency control schemes are employed to maintain the consistency of the database. Several semantic multi-granular lock based concurrency control schemes have been proposed in the literature. They have the drawback of either poor performance or high maintenance overhead when applied to continuously evolving domains. This paper proposes semantic lock-based concurrency control mechanism with better performance and nil maintenance overhead for continuously evolving OODBMS. It uses lock rippling to improve the performance.

In this work we investigate the effect of simple and efficient implementation of transition of IPv4 to IPv6 for BD-TTCS translator with list ranking algorithm using parallel computing task graph model (Diminution Tree) concept. In this work an unprecedented BD-TTCS IPv4/IPv6 translator is implemented with parallel computing based diminution tree. To corroborate the efficacy of the proposed method an experiment was conducted for various important performances issues namely Throughput, Round trip time, End-to-End delay, CPU utilization and simulated on NS2 simulator etc. In order to plot bar graph and Line Graph we used Matlab 7.11.0(R2010b).

Timed automata [1] are a well accepted formalism in modelling real time systems. In this paper, we study concurrent games with two players on timed automata with costs attached to the locations and edges and try to answer the question of the existence of Nash Equilibrium (NE). Considering memoryless strategies, we show that with one clock it is decidable whether there exists a NE where player 1 has a cost bounded by a constant

B

, while with 3 clocks, it is not. The case of 2 clocks is an interesting open question.

PageRank is a prominent metric used by search engines for ranking of search results. Page rank of a particular web page is a function of page ranks of all the web pages pointing to this page. The algorithm works on a large number of web pages and is thus computational intensive. The need of hardware is currently served by connecting thousands of computers in cluster. But faster and less complex alternatives to this system can be found in multi-core processors. In this paper, we identify major issues involved in porting PageRank algorithm on Cell BE Processor and CUDA, and their possible solutions. The work is evaluated on three input graphs of different sizes ranging from 0.35 million nodes to 1.3 million. Our results show that PageRank algorithm runs 2.8 times fast on CUDA compared to Xeon dual core 3.0 GHz.

Anonymity is one of the important properties of remote authentication schemes to preserve user privacy. Recently, Sood et al. showed that Wang et al.’s dynamic ID-based remote user authentication scheme fails to preserve user anonymity and is vulnerable to various attacks if the smart card is non-tamper resistant. Consequently, an improved version of dynamic ID-based authentication scheme was proposed and claimed that it is efficient and secure. In this paper, however, we will show that Sood et al.’s scheme still cannot preserve user anonymity under their assumption. In addition, their scheme is also vulnerable to the offline password guessing attack and the stolen verifier attack. To remedy these security flaws, we propose an enhanced authentication scheme, which covers all the identified weaknesses of Sood et al.’s scheme and is more secure and efficient for practical application environment.

This paper continues with the idea of social distance, proposed in [2] and introduces an algebra with two operators for

group social distance

and

lead distance

. It essentially extends the concept of social distance from individual level to group level, formally specifying how a group is socially distanced from an opportunity that intends development. It also proposes a measure to find how one influences others in a group resulting social improvement measured by a metric called

lead distance

. The paper analyzes the effects due to joining of different types of people where types are found based on their social privileges in accessing a social resource. Social difference between two is computed from their social distances, and the difference leads to social entropy of a group. Increase in entropy leads to group fragmentation. It is shown that group fragmentation can be controlled to give rise to desired sub groups. Our aim is to develop a computing methods for social engineering leading towards inclusive society.

In key assignment schemes for hierarchical access control systems, each access class has a key associated with it that can be used to derive the keys associated with every descendant of that class. Many recently proposed key assignment schemes support updates to the hierarchy such as addition and deletion of classes and class relationships. The dynamic changes entail a change to the hierarchy as well as re-computing of public and secret information. In this paper, we describe a software tool that supports the animation of specifications of dynamic schemes. The specification of a scheme, written in Prolog, corresponds to a symbolic model of the algorithms used by the scheme for key generation and for handling dynamic changes. The tool allows us to generate a test hierarchy, generate keys for the classes in the hierarchy, and simulate various dynamic operations. The animation search using the tool has shown to be useful in finding previously unreported attacks on several existing dynamic schemes.

Energy minimization and interference minimization are two of the main objectives of topology control problem in wireless sensor networks. Reducing interference lowers energy consumption by reducing the number of collisions and packet retransmissions on the media access layer. Reducing transmission energy increases the lifetime of the network. In order to increase the lifetime of the network it is important to fulfil both these objectives. However, the topology control problem of minimizing interference as well the the topology control problem of minimizing total transmission power are shown to be NP-Complete. Several heuristics have been proposed for minimizing the energy and interferences separately. Only few heuristics are available in the literature which address these two problems simultaneously. In this paper, we propose a local search based heuristic for the problem of assigning transmit power to each of the

n

sensors such that the total power consumption and interference is minimum along with the constraint that the resulting topology consisting of bidirectional links only is strongly connected. We prove that the transmission power resulting from this heuristic is at most twice the optimal. The simulation result shows that we get significant reduction in interference as compared to the interference of existing heuristics.

National Reproductive and Child Health program, focused on Mother and Child Health, part of Millennium Developmental Goals, is being implemented through Primary Health Centers of the Public Healthcare System. The health record generated through community health interventions are manual, leading to undue delay in diagnosis and emergency care. In this paper, we show how Distributed Processing and Internet Technology can be applied through innovative platform called

mHEALTH-PHC

, to provide timely, quality healthcare to remote population using existing infrastructure.

mHEALTH-PHC

combines client server, cellular, mobile phone technologies and medical test equipment to establish two way connection between patient in a village and Public Healthcare System. Our field study shows that

mHEALTH-PHC

can be effective in health surveillance, thereby leading to prompt, efficient, quality healthcare. We take the consortium approach involving IT and Public Health experts, Directorate of Health Services, pharmaceutical and health insurance industries, to make quality healthcare affordable and sustainable.

In self-organized ad hoc networks, all networking functions rely on the contribution of the relay nodes. Since nodes are energy constrained, nodes may not wish to relay packets for other nodes, hence leading to a drop in network throughput. In this paper, we address the issue of enforcement of cooperative behavior in network nodes. A number of approaches based either on credit or on reputation mechanisms have been proposed in the literature but these have been found to be largely unsatisfactory in the context of mobile ad hoc networks. A game theoretic approach to the solution to the cooperation problem that relies on rational and selfish behavior of network nodes may be more effective. This paper aims at determining conditions under which, such cooperation without external incentives can exist. We have focused on the packet forwarding function of the nodes and proposed a game theoretic model for achieving cooperation. Our simulation results show that cooperation is enforced in network based on a suitable strategy function under a wide range of parameters like strategies, initial condition of nodes, energy cost for sending or forwarding packets, traffic rate, noise effect, mobility, etc.

Cloud Computing is rapidly emerging and the new development in Information Technology. There are many patterns, or categories, in the world of cloud computing that are needed for the enterprise architecture. Some of the categories of services are storage, database, information, process, application, platform, integration, security, privacy, management/governance, testing, and infrastructure. Scalability is one of the important features applied on any of the services. The existing analysis specially focuses on Architectural and policy Implications without exploring the data privacy issues. In this paper, the application scalability and data privacy initiatives on various services in cloud environments are presented, with an overview of the trends they follow.

Recommender System has become the necessary agent for a naive user in the information bombardment arena of World Wide Web. In the last decade, World Wide Web emerged as an all encompassing technology that is revolutionizing the way people live. With the passage of time, user behaviors evolve and as such should be the recommendations provided. There exists a wide gap in literature to cater effectively with the issue of temporal evolution of data on the internet. This paper will specifically analyze various ways through which temporal issue can be handled in generating user profile that evolve with time. It will develop a recommendation model to handle the dynamics in user profile. The prime focal point is to examine if recommendation accuracy can be improved by adding temporal dimension. An empirical study is carried out to compare the analysis of the traditional data mining tasks and the proposed method.

Resource allocation is an important aspect in cloud computing. In Cloud Computing environment, the user can access required resources in the form of a service. The resource may be a platform, a software or infrastructure. In an IaaS (Infrastructure as a Service) Cloud, users send requests to the cloud-provider in the form of a

lease

; The cloud-provider makes a scheduling plan for leases in order to maximize the number of leases it can accommodate. A lease stores information about the required resources, including the time at which the resources are required.

Haizea

is a popular resource lease manager which handles the scheduling of such leases. An algorithm for deadline sensitive leases is presented which accepts more number of leases by dividing a lease into multiple slots and by backfilling already accommodated leases. Experimental results show that our scheduling algorithm gives better performance than existing algorithms in Haizea.

Grid system [1] involves the collaborative use of computers, networks, devices, software, databases and interfaces maintained by multiple organizations. In recent years, the development of Grid system [2], [3] has gained increasing interests from researchers. In this paper, a security solution is proposed for Grid system without public key settings.

Grid computing is concerned with a shared and coordinated use of heterogeneous resources, belongs to distributed virtual organizations to deliver nontrivial quality of services. In grids, security has a major concern. The heterogeneity, massiveness and dynamism of grid environments complicate and delay the authorization process. This brings out the need for a fast and scalable fine-grained access control (FGAC) mechanism to cater well to grid requirements.

Cloud computing involves highly variable resource requirement that demands high availability, scalability and performance. At times, single cloud service provider would be saturated or running out of resources and may be unable to provide the services to its client, resulting in poor scalability and reliability. It may tarnish the trust parameter of customer. In addition, there is huge investment in setting up a single scalable cloud, which in turn has many environmental impacts. In this work, we propose an architecture to inter-connect different clouds in P2P fashion to address the problems like efficiency bottleneck and single point of failure that are predominantly associated with traditional approaches. This idea gives access to much larger pools of resources/services. Each provider can maximize their profit by creating new collaborative services. These capabilities can be available and tradable through a service catalogue to support innovations and applications.

The problem of robust distributed estimation in wireless sensor network (WSN) when few sensor nodes are faulty is addressed here. In WSN, each sensor node collects scalar measurements of some unknown parameters and then estimates the parameter of interest from the data collected across the network. An iterative distributed linear parameter estimated algorithm is proposed here by using diffusion co-operation. Each node updates its information by using the data collected by it and the information received from the neighbours. The mean square error (MSE) of distributed estimation schemes increases whenever any faulty sensor node in the network fails to transmit correct information, which leads to inaccurate estimation. Hence a robust diffusion linear estimation algorithm using Hubber’s cost function is proposed here in order to improve the accuracy of the estimation.

In wireless sensor network each sensor node collects data related to some unknown parameters, corrupted by independent Gaussian noise. Then the objective is to estimate the parameter from the data collected across the network in distributed manner. The distributed estimation algorithm should be energy efficient, provides high estimation accuracy, and is fast in convergence. But the conventional distributed algorithm involves significant communication overhead and is also not robust to the impulsive noise which is common in wireless sensor network environment. Consequently these algorithms defeat the basic purpose of wireless sensor network. This paper studies the problem of robust adaptive estimation in impulsive noise environment using robust cost function like Wilcoxon norm and Huber cost function. Further in order to reduce the amount of communication overhead, block distributed LMS is incorporated.

The researches on utilizing mobile devices as resources in mobile cloud environments have been gained attentions recently because of the enhanced computer power of mobile devices with the advent of dual cores chips. In this paper, propose a resource allocation technique which offers reliable resource allocation considering the availability of mobile resources and movement reliability of mobile resources. We also demonstrate the performance of our technique through the experiments.

Transparency is being considered an indispensable ingredient in social accountability and necessary for preserving and guaranteeing ethical and fair processes. Transparency is related to visibility of information, and without it, work groups and stakeholders will be left in blind states. The growing importance to the requirement of transparency in business domains is the motivation to the present work. This paper presents a framework for transparency in the work groups and also specifies outlines for its implementation. This model can be used in organizations whose structure resembles the work group structure defined in this paper. This model does not incur much overhead as it involves only message passing for evaluating transparency of the work groups over tasks. Present day technologies are at such advanced levels that message passing even from very remote areas is not considered too difficult. According to this model, transparency of a work group can be evaluated during and after completion of task execution. During execution, if the task executing work group has reported sufficient number of transparency messages as defined by the task initiator till that time, then it is adjudged to be transparent; and the same applies even after completion of the task. The model tracks the levels of transparency and the shift between the levels/degrees (opaque, translucent, transparent), by requiring the task initiator to define the levels of transparency and the associated number and types of transparency messages, and the transparency of the task executor is evaluated by comparing the reported transparency messages with the required transparency messages. This model is most relevant to the Self Help Groups which are widely prevalent in India (about 3.37 million as of April 2011). However, it is applicable to any work group which resembles a SHG. A work group implies two or more individuals who routinely function like a team, and interdependent in achievement of a common goal, and may or may not work next to one another or in the same department. This kind of work groups are ever present in business domains. They represent a part of a business or the business itself. Transparency implies visibility of information related to financial and non-financial matters of the work group and its stakeholders. In the context of a business where several levels of administration are present, directions of transparency may take four directions: upwards, downwards, inwards, and outwards.

Upwards transparency

is meant to describe a hierarchical principal actor situation where the subordinate actor’s actions (or transactions) can be observed by the principal;

Downwards transparency

is the opposite of upwards, ie. when the principal can be observed by subordinate actors; Inwards transparency is the transparency to all the insiders of the work group and Outwards transparency is the transparency to all the outsiders of the work group. Financial reporting is tracking of monetary data and non-financial reporting is task’s execution-status data.We can classify transparency into three degrees :

opaqueness, translucency and clarity

. Opaqueness is when a work group does not disclose any information to its stakeholders and hence a opaque work group is not a transparent work group. Translucency is when a work group discloses its information partially. Hence, a translucent work group still cannot be called a transparent work group. Clarity is when a work group discloses all of its information. Only the work group having clarity degree of transparency is the transparent work group. Each task (w) will have three phases viz. pre-activity, per-activity and post-activity and transparency is defined on these three phases. Interestingly, the degree of transparency is directly proportional to the phases of activity. Prior to the pre-activity phase, the degree of transparency is opaque (or

null

). If the transparency conditions are met in the pre-activity phase, the degree becomes translucent. If the transparency conditions are met at per-activity phase and post-activity phases, then the degree of transparency becomes clear. As it is observed that after each activity phase, the degree of transparency is increasing, it is of interest to us to define the primary constituents of each activity phase which affect the degree of transparency. At each activity phase we define the transparency dimensions that are required. Though transparency dimensions are taskand situation-dependent, the following dimensions are mandatory.

Recognition of responsibilities

and interdependencies are primarily of concern before the realization of a given activity (pre-activity).

Recognition of status and problems

are primarily related to transparency into an ongoing activity (per-activity). Similarly,

understanding of performance and feedback

are related to post-activity transparency. There are three main perspectives in Transparency:

static , dynamic and radical

. In Static Transparency, the flow of information is mainly unidirectional i.e. from the work group to stakeholders. In

Dynamic Transparency

the work gorup and its stakeholders can exchange, share and compare information and adapt its online behavior and electronic requests and queries to the answers and reactions of respective counterparts.

Radical Transparency

refers to the capability of a firm’s top management to employ internet-based technologies, such as rss, blogs and collaborative websites, in order to create a direct and continuous dialogue with customers and other stakeholders. Implementation of transparency in such a work group can be made using Member Behavior Model [MBM] and Task Execution Cycle [TEC]. MBM outlines the behavior of every member in a work group and also of the work group. MBM provides an imprint of generic behavior of each member ( or work group) and TEC gives the different states of an executing task. Relation between MBM and TEC is that TEC is an integral part of ExTsk of the MBM. Transparency metric quantifies the levels of transparency of the work group or a member based on the transparency messages. Each transparency message can also be provided with a value corresponding to its priority. Thus, depending on the number of messages and the values associated with the messages, transparency can be computed. Since each activity has three phases i.e. pre, per and post , the transparency is a sum of transparencies of these three phases. Thus the present paper successfully

defines

and outlines

implementation

of Transparency.

A star graph

S

n

[1], of order

n

, is defined to be a symmetric graph

G

 = (

V

,

E

) where

V

is the set of

n

! vertices, each representing a distinct permutation of

n

elements and

E

is the set of symmetric edges such that two permutations (nodes) are connected by an edge iff one can be reached from the other by interchanging its first symbol with any other symbol. The star graph

S

n

is a (

n

 − 1)-regular graph with

n

! nodes and

n

!(

n

 − 1)/2 edges. Recursive hierarchical structure is one of the most attractive and well known properties of star graphs. A dimension

n

star graph can be divided into

n

substars of dimension

n

 − 1 by grouping the nodes with the same symbol at the

i

th position together, 2 ≤ 

i

 ≤ 

n

[see Figure 1].

In this paper, we propose a new recursive hierarchical structure of star graphs. The objective is to redesign shortest routing in star graphs in the light of this new structure and design new efficient algorithms for shortest path multicast algorithms [2] adaptibe to bandwidth and latency requirements.

On the World Wide Web a large numbers of information is available in the form of semi-structured format. Knowledge discovery in semi-structured document has been recognized as promising task. Since semi structured document is typically hidden within HTML formatting intended for human viewing the details of which vary widely from site to site and frequent changes made to their formatting so we can’t construct a global schema, discovery of interesting rules form it is complex and tedious process. Most of the existing system uses hand-coded wrappers to extract information, which is monotonous and time consuming. An intelligent and automated method is needed for their processing. Learning grammatical information from given sample of semi-structured documents has attracted lots of attention in the past decades. To understand “what say the data” is necessary to know the structure of data to discover the syntactic-semantic knowledge of its language.

The problem of learning the correct grammar for the unknown language form finite example of the language is known as grammatical inference problem. In automated grammar learning, the task is to infer grammar rules from given information about the target language. If example belongs to the target language it is called positive example otherwise it is called negative example. In this paper we propose a grammar inference methodology to automate the construction of grammar rules and facilitate the process of information extraction. We are using hybrid technique of association analysis and sequential algorithm to generate context free grammar rules from semi-structured document (HTML document).

Our algorithm that infers a sequential pattern from a sequence of discrete HTML tags. The basic insight is that sub-string is selected on the basis of high support factor by taking entire sentences into account. Which appears more frequently in string can be replaced by a grammatical rule that generate the sub-string, and this process is repeated many times, producing a single length rules of the sequence. The result is strictly a context-free grammar rules, which provide a compact summary of corpora that aids understanding of its properties.

A Petri net can be represented as a particular kind of bipartite graph consisting of two kinds of nodes called places and transitions. Directed arcs are used to connect places to transitions (output of places) and to connect transitions to places (input of places). The study of structural properties and behavioral properties for the bounded conflict free Petri net has been made utilizing siphons and traps [2].

Web services have gained popularity with increasing number of businesses available on web. Huge increase in the number of services available on web makes service discovery a difficult problem. The process of discovery has graduated from syntax based to semantic based search. And there has been a spurt of research in specification and discovery of web services. The research work can be broadly classified to the following categories (1) WSDL Input Output Match (2) WSDL Input Output Precondition & Effect (Capability based) Match (3) Function semantics based Matching.

The work presented includes a prototype that demonstrates semantic search using constrained spread activation for relationship inference for semantic digital library domain. A java applet forms the basic user interface for this prototype. The user submits search query which is expanded using semantic digital library domain ontology. Based on the expanded query, initial nodes are activated and the activation is made to travel to other nodes using the constrained spread algorithm. The spread is constrained by making use of the distance constraint, which is supplied by the user. . The semantic search proposed here is the combination of spread activation techniques with traditional search engines techniques to obtain its results.