Theses and Dissertations

Permanent URI for this collectionhttp://ir.daiict.ac.in/handle/123456789/1

Browse

Subject: search.filters.subject.Mobile computing

Search Results

Now showing 1 - 7 of 7
  • Thumbnail Image
    ItemOpen Access
    Privacy preserving identity verification with binding blinding technique in cloud assisted healthcare applications
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2018) Patwa, Dolly R.; Das, Manik Lal
    In recent times, broad deployment of computers and mobile devices such as mobile phones, PDA's rigged with cost efficient sensors, have shown great potential in recognizing positive direction to healthcare services. It serves patients even in the remote locations. Remote patient monitoring enables serving patients outside of clinical conventional setting at hospitals. It may increase easy caring and monitoring of health frequently and decrease healthcare delivery costs. Healthcare applications for chronic diseases have significantly improved user's quality of life. It allows user to monitor his health frequently and decreases cost since he get personalized care as conventional doctor and hospital settings. mHealth is abbreviation of mobile health. It involves provision of healthcare services via smart phones and attached wearable wireless devices. Several healthcare systems proposed and it discusses privacy of user and security of user's data. Healthcare system involves healthcare companies, user and cloud mainly as participating entities in the system. Privacy should be maintained in a sense that nobody other than the user should be able to know his current health condition and get appropriate personalized care. Since companies lack of storage and computational resources, security of user's medical data is at risk. Several healthcare application systems have been proposed over the past decade yet user's privacy and security is a potential threat to such a system. Therefore, analysis of such systems is required. In this thesis work, we analyzed a healthcare application system and found outsider attack and proposed mitigation to prevent this attack. Our proposed mitigation borrows the idea of binding-blinding technique. We made security analysis of our proposed scheme as well as its performance analysis.
  • Thumbnail Image
    ItemOpen Access
    Privacy preservation in vehicular ad-hoc networks (VANETs)
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2015) Garg, Garima; Das, Manik Lal
    Vehicular Ad-hoc Networks (VANETs) are the special application of Mobile Ad-hoc Networks (MANETs). Due to increase in the number of road accidents, VANETs provide security to road traffic by sending safety messages to other vehicles. However, the safety messages provide safety from accidents, the privacy of the vehicles from adversaries is also a concern. Vehicles have to preserve the privacy of contextual information like identity of the vehicle, location of the vehicle, speed of the vehicle and route etc. Therefore, the privacy preservation of vehicle is important because by using the vehicle’s information an adversary can easily send false information to other vehicles which can cause a road accident. One of the methods to preserve privacy in VANETs is by using Pseudonym Identities (PIDs). PIDs are not real IDs of the vehicles. PIDs are different from Real Identities (RID) of vehicles. We have suggested an approach for privacy preservation in VANETs using PIDs and Certificate-Less SignCryption (CLSC) [16] scheme as cryptographic primitive. This approach is more secure over hash-chain based and certificate-based schemes. We have also simulated a hash-chain based scheme which is better than hash-chain based scheme described in [7]. However, the scheme has many limitations therefore we moved on to certificate-less based schemes after reviewing the certificate-based scheme’s limitations. The proposed scheme uses CLSC as cryptographic primitive and there are two more system components other than the vehicle, RSU and CA. The VANET system is divided into zones and each zone has a ZRSU which provide credentials to the vehicle and when a vehicle moves from its home zone to other zone handover is done. Vehicles contact to PKGC in handover phase. PKGC is situated at the separation point of two zones. The Proposed approach is secure and efficient. It provides privacy for vehicles.
  • Thumbnail Image
    ItemOpen Access
    Mobility models and its application in ad-hoc network
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2011) Jain, Vikas Kumar; Patil, Hemant A.; Mulherkar, Jaideep
    The Performance of MANET application depends on several parameters like no. of nodes, node density, communicating traffic pattern, communication range of a node, routing protocol, battery power of a node, mobility etc. Out these mobility plays an important role. Mobility model describe the mobility pattern of mobile nodes and users like how their location, velocity, direction and acceleration will change with respect to time. There are some of the mobility models like Random Way Point, Gauss Markov mobility model, Reference Point Group mobility model and Manhattan mobility model. Since simulate on plays an important role in conducting the research and to know the performance ofmany MANET applications, hence it is important to choose the appropriate mobility model. Generally, all the simulation work is done by choosing the Random Way Point mobility model because of its simplicity but it is unable to capture a real life scenario. RWP has several limitations so it cannot be applied for each MANET applications. A lot of work has been done by the researchers to design mobility models which are able to capture real life scenario. Accurate realistic modeling is a very challenging task and involves huge efforts. This work intends towards proposing a method to answer about best fit mobility model for the given trace along with confidence level and parameters values of the model. If we use best fit mobility model according to the given trace then accuracy of the results will improve. This work mainly focuses on RWP and RPGM mobility model. Also the proposed method are applied on a ad hoc wireless sensor network application called Zebra Net trace, to answer about the best fit mobility model out of RWP and RPGM.
  • Thumbnail Image
    ItemOpen Access
    Analysis of address allocation protocols for mobile ad hoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2011) Sati, Mohit; Srivastava, Sanjay; Divakaran, Srikrishnan
    In almost all networks, it is necessary to have a unique identifier for each node. This identifier is used to find out route locating a particular node. So an address is must for any node for unicast communication. Addresses can be preconfigured manually or can be assigned dynamically using a server (e.g. DHCP server). Manual configuration of ad hoc network is not possible for large scale networks. And setting up a server is not possible due to lack of infrastructure in Ad Hoc Networks. So it is necessary to have a mechanism by which we can allocate addresses to the nodes dynamically without any prior setup. Lack of infrastructure and mobility of nodes makes address allocation a challenging task in MANET. We present worst case message complexity analysis of a number of proposed address allocation protocols, which can be useful for estimating upper bounds for overhead and latency involved in address allocation as well as partitioning and merging. We also show that the worst case analysis is not a useful indicator of real world performance of the protocols. Buddy approach [5] is one of the many proposed approaches for address allocation. We model DPDA (A Distributed Protocol for Dynamic Address assignment in mobile ado networks)[6], a protocol based on buddy approach, to estimate the overhead involved in address allocation. We conduct simulations in NS-2 and compare with analytical results to validate our model. We perform simplified simulations using Python script which also validates the proposed model. We also do a simulation based comparison of MANETconf (MANET configuration) [8] and DPDA[6] in term of overhead and latency in address allocation, which shows that DPDA causes lower communication overhead and latency than Manetconf.
  • Thumbnail Image
    ItemOpen Access
    Scalable routing in mobile ad hoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Patel, Brijesh; Srivastava, Sanjay
    In Mobile Ad Hoc Networks (MANETs), performing routing is a challenging task in presence of the varying network parameters like node mobility, traffic and network size. It is very important to analyze the scalability characteristics of the routing protocols with respect to these parameters. ZRP is considered to be one of the most scalable routing protocols due to its multiscoping and hybridization features. We propose a general, parameterized model for analyzing control overhead of ZRP. A generic probabilistic model for data traffic is also proposed which can be replaced by different traffic models. Our analytical model is validated by comparisons with simulations performed on different scenarios. In our simulation results we have observed that the optimal zone radius lies where the proactive and reactive overhead components of ZRP are approximately equal as observed in [19]. We have also observed that optimal zone radius setting is different under different network conditions. Our simulations show that as the mobility increases the optimal zone radius value decreases, and as the traffic increases the value of optimal zone radius increases. Moreover, if a node operates away from the optimal zone radius setting then it has to bear and ditional routing overhead. Our simulations show that this deviation is quite high in case of low mobility (upto 35%) than in high mobility (upto 23%).
  • Thumbnail Image
    ItemOpen Access
    Analysis of address allocation protocols for mobile ad hoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Sheth, Kavan J.; Srivastava, Sanjay
    In almost all networks, it is necessary to have a unique identifier for each node. This identifier is used to find out route locating a particular node. So an address is must for any node for unicast communication. Addresses can be preconfigured manually or can be assigned dynamically using a server (e.g. DHCP server). Manual configuration of ad hoc network is not possible for large scale networks. And setting up a server is not possible due to lack of infrastructure in Ad Hoc Networks. So it is necessary to have a mechanism by which we can allocate addresses to the nodes dynamically without any prior setup. Lack of infrastructure and mobility of nodes makes address allocation a challenging task in MANET. We present worst case message complexity analysis of a number of proposed address allocation protocols, which can be useful for estimating upper bounds for overhead and latency involved in address allocation as well as partitioning and merging. We also show that the worst case analysis is not a useful indicator of real world performance of the protocols. Buddy approach [5] is one of the many proposed approaches for address allocation. We model DPDA (A Distributed Protocol for Dynamic Address assignment in mobile ado networks)[6], a protocol based on buddy approach, to estimate the overhead involved in address allocation. We conduct simulations in NS-2 and compare with analytical results to validate our model. We perform simplified simulations using Python script which also validates the proposed model. We also do a simulation based comparison of MANETconf (MANET configuration) [8] and DPDA[6] in term of overhead and latency in address allocation, which shows that DPDA causes lower communication overhead and latency than Manetconf.
  • Thumbnail Image
    ItemOpen Access
    Modeling MANETs using queuing networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2007) Munjal, Aarti; Srivastava, Sanjay; Lenin, R. B.
    Mobile Ad Hoc Networks (MANETs) are becoming an attractive solution to the services that require flexible establishment, dynamic and low cost wireless connectivity. Since nodes are mobile, routing results vary significantly with the underlying mobility model. So, modeling (nodes as well as wireless links between them) plays a critical role in the performance analysis of MANETs. This work involves modeling MANETs in two ways. In the first model, nodes are modeled as static and wireless links between a pair of nodes are available or unavailable for exponential durations. When the link is available, nodes are connected and can have data transmission and data are lost if the link is not available as the nodes are not connected. Second model involves mobility being captured by making the servers go ON/OFF for exponential amount of time, and no departure takes place while server is on vacation. This way one does not lose packets but the queuing delay increases. In this work, these two queuing networks are proposed to study to performance measures of MANETs. Numerical results are derived using mathematical equations and then verified through simulation.