Papers by Atta ur Rehman Khan
Due to the limited computational capability of mobile devices, the research organization and acad... more Due to the limited computational capability of mobile devices, the research organization and academia are working on computationally secure schemes that have capability for offloading the computational intensive data access operations on the cloud/trusted entity for execution. Most of the existing security schemes, such as proxy re-encryption, manager-based re-encryption, and cloud-based re-encryption, are based on El-Gamal cryptosystem for offloading the computational intensive data access operation on the cloud/trusted entity. However, the resource hungry pairingbased cryptographic operations, such as encryption and decryption, are executed using the limited computational power of mobile device. Similarly, if the data owner wants to modify the encrypted file uploaded on the cloud storage, after modification the data owner must encrypt and upload the entire file on the cloud storage without consider-ing the altered portion(s) of the file. In this paper, we have proposed an incremental version of proxy re-encryption scheme for improving the file modification operation and compared with the original version of the proxy re-encryption scheme on the basis of turnaround time, energy consumption, CPU utilization, and memory consumption while executing the security operations on mobile device. The incremental version of proxy re-encryption scheme shows significant improvement in results while performing file modification operations using limited processing capability of mobile devices.
We study the challenging problem of the network partitioning and merging in context with the mism... more We study the challenging problem of the network partitioning and merging in context with the mismatch problem and the resilience of the logical structure in distributed hash table (DHT)-based routing protocols for mobile ad hoc networks (MANETs). The existing DHT-based approaches for routing in MANETs do not consider the merging of logical networks, which occurs because of limited transmission range and mobility of nodes. In this paper, we identify that the mismatch problem is aggravated when logical networks are merged, which directly depends upon the shape of the logical structure in which nodes are arranged according to their logical identifier. To address this problem, we first propose a leader-based approach (LA) to detect and merge logical networks. In addition, we discuss the effectiveness of a three-dimensional logical space and three-dimensional logical structure when logical networks are merged. In three-dimensional logical space and three-dimensional logical structure, we take into account the physical intra-neighbour relationship of a node and interpret that relationship in terms of logical identifiers. Simulation results show that the proposed DHT-based protocol along with LA outperforms the existing DHT-based routing protocol in terms routing overhead, end-to-end delay, path-stretch values and packet delivery ratio.
This paper presents a comparison of cluster-based position and non position-based routing protoco... more This paper presents a comparison of cluster-based position and non position-based routing protocols for mobile wireless sensor networks to outline design considerations of protocols for mobile environments. The selected protocols are compared on the basis of multiple parameters, which include packet delivery ratio, packet loss, network lifetime, and control overhead using variable number of nodes and speeds. The extensive simulation and analysis of results show that position-based routing protocols incur less packet loss as compared to the non position based protocols. However, position-based protocols require localization mechanism or a GPS for the location information, which consumes energy and affects the network lifetime. Alternatively, non position-based protocols are more energy efficient and provide extended network lifetime.
Cloud computing is an emerging computing paradigm that offers on-demand, flexible, and elastic co... more Cloud computing is an emerging computing paradigm that offers on-demand, flexible, and elastic computational and storage services for the end-users. The small and medium-sized business organization having limited budget can enjoy the scalable services of the cloud. However, the migration of the organizational data on the cloud raises security and privacy issues. To keep the data confidential, the data should be encrypted using such cryptography method that provides fine-grained and efficient on the mobile device as compared to existing reencryption schemes.
For the last few years, academia and research organizations are continuously investigating and re... more For the last few years, academia and research organizations are continuously investigating and resolving the security and privacy issues of mobile cloud computing environment. The additional consideration in designing security services for mobile cloud computing environment should be the resource-constrained mobile devices. The execution of computationally intensive security services on mobile device consumes battery's charging quickly. In this regard, the study presents a novel energy-efficient block-based sharing scheme that provides confidentiality and integrity services for mobile users in the cloud environment. The block-based sharing scheme is compared with the existing schemes on the basis of energy consumption, CPU utilization, memory utilization, encryption time, decryption time, and turnaround time. The experimen- A. N. Khan et al. tal results show that the block-based sharing scheme consumes less energy, reduces the resources utilization, improves response time, and provides better security services to the mobile users in the presence of fully untrusted cloud server(s) as compared to the existing security schemes.
Cloud computing has emerged as a popular computing paradigm for hosting large computing systems a... more Cloud computing has emerged as a popular computing paradigm for hosting large computing systems and services. Recently, significant research is carried out on Resource Management (RM) techniques that focus on the efficient sharing of cloud resources among multiple users. RM techniques in cloud are designed for computing and workload intensive applications that have different optimization parameters. This study presents a comprehensive review of RM techniques and elaborates their extensive taxonomy based on the distinct features. It highlights evaluation parameters and platforms that are used to evaluate RM techniques. Moreover, it presents design goals and research challenges that should be considered while proposing novel RM techniques.
In the last few years, distributed hash table (DHT) has come forth as a useful addition to the de... more In the last few years, distributed hash table (DHT) has come forth as a useful addition to the design and specification of spontaneous, self-organizing networks. Researchers have exploited its advantages by implementing it at the network layer in order to design scalable routing protocols for mobile ad hoc networks. We identify two correlated issues that must be considered when designing DHTbased routing protocol, namely the mismatch problem and resilience of the logical network, which degrades the efficiency of the DHT-based routing protocols. To address these problems, we propose a DHT-based routing protocol that exploits a 3D logical space that takes into account the physical intra-neighbor relationships of a node and exploits a 3D structure to interpret that relationship. In the proposed scheme, each node runs a distributed algorithm to obtain a consecutive logical identifier that reflects its physical proximity in the 3D logical space. Moreover, the protocol utilizes the 3D-structure to maintain multi-paths to a destination node in order to address the scalability problem and gain resilience against a node/link failure. Simulation results show that the proposed approach outperforms the existing DHT-based routing protocol in terms routing overhead, end-to-end delay, path-stretch values and packet-delivery ratio.
To improve the resource limitation of mobile devices, mobile users may utilize cloud-computationa... more To improve the resource limitation of mobile devices, mobile users may utilize cloud-computational and storage services. Although the utilization of the cloud services improves the processing and storage capacity of mobile devices, the migration of confidential information on untrusted cloud raises security and privacy issues. Considering the security of mobile-cloud-computing subscribers' information, a mechanism to authenticate legitimate mobile users in the cloud environment is sought. Usually, the mobile users are authenticated in the cloud environment through digital credential methods, such as password. Once the users' credential information theft occurs, the adversary can use the hacked information for impersonating the mobile user later on. The alarming situation is that the mobile user is unaware about adversary's malicious activities. In this paper, a light-weight security scheme is proposed for mobile user in cloud environment to protect the mobile user's identity with dynamic credentials. The proposed scheme offloads the frequently occurring dynamic credential generation operations on a trusted entity to keep minimum processing bur-den on the mobile device. To enhance the security and reliability of the scheme, the credential information is updated frequently on the basis of mobile-cloud packets exchange. Furthermore, the proposed scheme is compared with the existing scheme on the basis of performance metrics i.e. turnaround time and energy consumption. The experimental results for the proposed scheme showed significant improvement in turnaround time and energy consumption as compared to the existing scheme.
Recent growth in the processing and memory resources of mobile devices has fueled research within... more Recent growth in the processing and memory resources of mobile devices has fueled research within the field of mobile virtualization. Mobile virtualization enables multiple persona on a single mobile device by hosting heterogeneous operating systems (OSs) concurrently. However, adding a virtualization layer to resourceconstrained mobile devices with real-time requirements can lead to intolerable performance overheads. Hardware virtualization extensions that support efficient virtualization have been incorporated in recent mobile processors. Prior to hardware virtualization extensions, virtualization techniques that are enabled by performance prohibitive and resource consuming software were adopted for mobile devices. Moreover, mobile virtualization solutions lack standard procedures for device component sharing and interfacing between multiple OSSs. The objective of this article is to survey software-and hardware-based mobile virtualization techniques in light of the recent advancements fueled by the hardware support for mobile virtualization. Challenges and issues faced in virtualization of CPU, memory, I/O, interrupt, and network interfaces are highlighted. Moreover, various performance parameters are presented in a detailed comparative analysis to quantify the efficiency of mobile virtualization techniques and solutions.
Vehicular Ad hoc Networks have gained high popularity for their interesting applications. However... more Vehicular Ad hoc Networks have gained high popularity for their interesting applications. However, routing in mobile networks is a challenging task and requires specialized routing protocols, which are designed to address mobile environment factors, such as inconsistent connectivity, high mobility, and communication obstacles. In this paper, we present a qualitative comparative study of well-known position based routing protocols for highway and city environment. Moreover, we investigate impact of different forwarding strategies on the behavior of routing protocols using extensive simulations and detailed analysis. The results show that greedy forwarding and improved greedy forwarding outperform directional and predictive forwarding strategies. It is also observed that dynamic junction selection is more suitable for routing in city environment.
Over the last few years, vehicular ad hoc networks (VANETs) have gained popularity for their inte... more Over the last few years, vehicular ad hoc networks (VANETs) have gained popularity for their interesting applications. To make efficient routing decisions, VANET routing protocols require road traffic density information for which they use density estimation schemes. This paper presents a distributed mechanism for road vehicular density estimation that considers multiple road factors, such as road length and junctions. Extensive simulations are carried out to analyze the effectiveness of the proposed technique. Simulation results suggested that, the proposed technique is more accurate compared to the existing technique. Moreover, it facilitate VANET routing protocols to increase packet delivery ratio and reduce end-to-end delay.
Mobile cloud computing is an emerging technology that is gaining popularity as a means to extend ... more Mobile cloud computing is an emerging technology that is gaining popularity as a means to extend the capabilities of resource-constrained mobile devices such as a smartphone. Mobile cloud computing requires specialized application development models that support computation offloading from a mobile device to the cloud. The computation offloading is performed by means of offloading application process, application component, entire application, or clone of the smartphone. The offloading of an entire application or clone of the smartphone to cloud may raise application piracy issues, which, unfortunately, have not been addressed in the existing literature. This paper presents a piracy control framework for mobile cloud environment, named Pirax, which prevents mobile applications from executing on unauthenticated devices and cloud resources. Pirax is formally verified using High Level Petri Nets, Satisfiability Modulo Theories Library and Z3 solver. Pirax is implemented on Android platform and analyzed from security and performance perspectives. The performance analysis results show that Pirax is lightweight and easy to integrate into existing mobile cloud application development models.
Mobile cloud computing presents an effective solution to overcome smartphone constraints, such as... more Mobile cloud computing presents an effective solution to overcome smartphone constraints, such as limited computational power, storage, and energy. As the traditional mobile application development models do not support computation offloading, mobile cloud computing requires novel application development models that can facilitate the development of cloud enabled mobile applications. This paper presents a mobile cloud application development model, named MobiByte, to enhance mobile device applications' performance, energy efficiency, and execution support. MobiByte is a context-aware application model that uses multiple data offloading techniques to support a wide range of applications. The proposed model is validated using prototype applications and detailed results are presented. Moreover, MobiByte is compared with the most recent application models with a conclusion that it outperforms the existing application models in many aspects like energy efficiency, performance, generality, context awareness, and privacy.
This paper presents two new routing protocols for mobile sensor networks, viz. power-controlled r... more This paper presents two new routing protocols for mobile sensor networks, viz. power-controlled routing (PCR) and its enhanced version, i.e. enhanced power-controlled routing (EPCR). In both the protocols, fixed transmission power is employed in the clustering phase but when ordinary nodes are about to send their data to their respective cluster-heads, they change their transmission power according to their distance from their cluster-head. While in PCR, the nodes are associated with the cluster-head on the basis of weight, in EPCR it is done on the basis of distance. In addition to the protocols, we are suggesting a packet loss recovery mechanism for the PCR and EPCR. Both protocols work well for both mobile and static networks and are designed to achieve high network lifetime, high packet delivery ratio, and high network throughput. These protocols are extensively simulated using mass mobility model, with different speeds and different number of nodes to evaluate their performance. Simulation results show that both PCR and EPCR are successful in achieving their objectives by using variable transmission powers and smart clustering.
Smartphones are now capable of supporting a wide range of applications, many of which demand an e... more Smartphones are now capable of supporting a wide range of applications, many of which demand an ever increasing computational power. This poses a challenge because smartphones are resource-constrained devices with limited computation power, memory, storage, and energy. Fortunately, the cloud computing technology offers virtually unlimited dynamic resources for computation, storage, and service provision. Therefore, researchers envision extending cloud computing services to mobile devices to overcome the smartphones constraints. The challenge in doing so is that the traditional smartphone application models do not support the development of applications that can incorporate cloud computing features and requires specialized mobile cloud application models. This article presents mobile cloud architecture, offloading decision affecting entities, application models classification, the latest mobile cloud application models, their critical analysis and future research directions.
We study the challenging problem of the network partitioning and merging in context with the mism... more We study the challenging problem of the network partitioning and merging in context with the mismatch problem and the resilience of the logical structure in distributed hash table (DHT)-based routing protocols for mobile ad hoc networks (MANETs). The existing DHT-based approaches for routing in MANETs do not consider the merging of logical networks, which occurs because of limited transmission range and mobility of nodes. In this paper, we identify that the mismatch problem is aggravated when logical networks are merged, which directly depends upon the shape of the logical structure in which nodes are arranged according to their logical identifier. To address this problem, we first propose a leader-based approach (LA) to detect and merge logical networks. In addition, we discuss the effectiveness of a three-dimensional logical space and three-dimensional logical structure when logical networks are merged. In three-dimensional logical space and three-dimensional logical structure, we take into account the physical intra-neighbour relationship of a node and interpret that relationship in terms of logical identifiers. Simulation results show that the proposed DHT-based protocol along with LA outperforms the existing DHT-based routing protocol in terms routing overhead, end-to-end delay, path-stretch values and packet delivery ratio.
Mobile cloud computing presents an effective solution to overcome smartphone constraints, such as... more Mobile cloud computing presents an effective solution to overcome smartphone constraints, such as limited computational power, storage, and energy. As the traditional mobile application development models do not support computation offloading, mobile cloud computing requires novel application development models that can facilitate the development of cloud enabled mobile applications. This paper presents a mobile cloud application development model, named MobiByte, to enhance mobile device applications' performance, energy efficiency, and execution support. MobiByte is a context-aware application model that uses multiple data offloading techniques to support a wide range of applications. The proposed model is validated using prototype applications and detailed results are presented. Moreover, MobiByte is compared with the most recent application models with a conclusion that it outperforms the existing application models in many aspects like energy efficiency, performance, generality, context awareness, and privacy.
—Smartphones are now capable of supporting a wide range of applications, many of which demand an ... more —Smartphones are now capable of supporting a wide range of applications, many of which demand an ever increasing computational power. This poses a challenge because smartphones are resource-constrained devices with limited computation power, memory, storage, and energy. Fortunately, the cloud computing technology offers virtually unlimited dynamic resources for computation, storage, and service provision. Therefore , researchers envision extending cloud computing services to mobile devices to overcome the smartphones constraints. The challenge in doing so is that the traditional smartphone application models do not support the development of applications that can incorporate cloud computing features and requires specialized mobile cloud application models. This article presents mobile cloud architecture, offloading decision affecting entities, application models classification, the latest mobile cloud application models, their critical analysis and future research directions.
— Internet is composed of numbers of independent autonomous systems. BGP is used to disseminate r... more — Internet is composed of numbers of independent autonomous systems. BGP is used to disseminate reachability information and establishing path between autonomous systems. Each autonomous system is allowed to select a single route to a destination and then export the selected route to its neighbors. The selection of single best route imposes restrictions on the use of alternative paths during interdomain link failure and thus, incurred packet loss. Packet loss still occurs even when multiple paths exist between source and destination but these paths have not been utilized. To minimize the packet loss, when multiple paths exist, multipath routing techniques are introduced. Multipath routing techniques ensure the use of alternative paths on link failure. It computes set of paths which can be used when primary path is not available and it also provides a way to transit domains to have control over the traffic flow. This can be achieved by little modification to current BGP. This paper highlights different multipath routing techniques and also discusses the overhead incurred by each of them.
— This paper presents comparison of different hierarchical (position and non-position based) prot... more — This paper presents comparison of different hierarchical (position and non-position based) protocols with respect to different mobility models. Previous work mainly focuses on static networks or at most a single mobility model. Using only one mobility model may not predict the behavior of routing protocol accurately. Simulation results show that mobility has large impact on the behavior of WSN routing protocols. Also, position based routing protocols performs better in terms of packet delivery compared to non position based routing protocols.
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Papers by Atta ur Rehman Khan