National Institute of Technology Sikkim

About: National Institute of Technology Sikkim is a education organization based out in Gangtok, India. It is known for research contribution in the topics: Computer science & Monopole antenna. The organization has 170 authors who have published 314 publications receiving 1418 citations.

A critical survey of live virtual machine migration techniques

Abstract: Virtualization techniques effectively handle the growing demand for computing, storage, and communication resources in large-scale Cloud Data Centers (CDC). It helps to achieve different resource management objectives like load balancing, online system maintenance, proactive fault tolerance, power management, and resource sharing through Virtual Machine (VM) migration. VM migration is a resource-intensive procedure as VM's continuously demand appropriate CPU cycles, cache memory, memory capacity, and communication bandwidth. Therefore, this process degrades the performance of running applications and adversely affects efficiency of the data centers, particularly when Service Level Agreements (SLA) and critical business objectives are to be met. Live VM migration is frequently used because it allows the availability of application service, while migration is performed. In this paper, we make an exhaustive survey of the literature on live VM migration and analyze the various proposed mechanisms. We first classify the types of Live VM migration (single, multiple and hybrid). Next, we categorize VM migration techniques based on duplication mechanisms (replication, de-duplication, redundancy, and compression) and awareness of context (dependency, soft page, dirty page, and page fault) and evaluate the various Live VM migration techniques. We discuss various performance metrics like application service downtime, total migration time and amount of data transferred. CPU, memory and storage data is transferred during the process of VM migration and we identify the category of data that needs to be transferred in each case. We present a brief discussion on security threats in live VM migration and categories them in three different classes (control plane, data plane, and migration module). We also explain the security requirements and existing solutions to mitigate possible attacks. Specific gaps are identified and the research challenges in improving the performance of live VM migration are highlighted. The significance of this work is that it presents the background of live VM migration techniques and an in depth review which will be helpful for cloud professionals and researchers to further explore the challenges and provide optimal solutions.

Coverage and connectivity aware energy efficient scheduling in target based wireless sensor networks: an improved genetic algorithm based approach

Abstract: Energy efficient scheduling of sensor nodes is one of the most efficient techniques to extend the lifetime of the wireless sensor networks (WSNs). Instead of activating all the deployed sensor nodes, a set of sensor nodes are activated or scheduled to monitor the targeted region. While scheduling with lesser number of sensor nodes, coverage and connectivity of the network should be taken care due to the limited sensing and communication range of the sensor nodes. In this paper, we have proposed an improved genetic algorithm (GA) based scheduling for WSNs. An efficient chromosome representation is given and it is shown to generate valid chromosome after crossover and mutation operation. The fitness function is derived with four conflicting objectives, selection of minimum number of sensor nodes, full coverage, connectivity and energy level of the selected sensor nodes. We have introduced a novel mutation operation for better performance and faster convergence of the proposed GA based approaches. We have also formulated the scheduling problem as a Linear Programming. Extensive simulation is performed on various network scenarios by varying number of deployed sensor nodes, target point and network length. We also perform a popular statistical test, analysis of variance followed by post hoc analysis.

An elliptic curve cryptography based enhanced anonymous authentication protocol for wearable health monitoring systems

Abstract: The innovations in the field of wearable medical devices, wireless communication and low cost cloud computing aid the wireless body area network (WBAN) to become a prominent component of future healthcare systems. WBAN consists of medical sensors, which continuously monitor the patients’ vital signs and transfers this data to the remote medical server via the cloud. The continuous monitoring of the patients’ health data improves the quality of the medical service and also provides the source for future medical diagnosis. The medical information collected from WBAN is generally transmitted through wireless channel and therefore vulnerable to various information attacks. In this context, medical data security and privacy are key issues; hence there is a requirement of lightweight end-to-end authentication protocol to ensure secure communication. Recently, Li et al. presented a lightweight end-to-end authentication protocol for WBAN based on elliptic curve cryptography (ECC). However, through cryptanalysis, some security loopholes are found in this protocol. In this paper, an enhanced lightweight ECC based end-to-end authentication protocol is proposed to overcome the security vulnerabilities of Li et al.’s scheme. Further, the formal security analysis of the proposed scheme is done using BAN logic and AVISPA tool. The comparative analysis shows that the proposed scheme not only removes the security loopholes of Li et al.’s scheme but also reduces the overall complexity.

A lightweight remote user authentication scheme for IoT communication using elliptic curve cryptography

Abstract: Internet of things (IoT) has become a new era of communication technology for performing information exchange. With the immense increment of usage of smart devices, IoT services become more accessible. To perform secure transmission of data between IoT network and remote user, mutual authentication, and session key negotiation play a key role. In this research, we have proposed an ECC-based three-factor remote user authentication scheme that runs in the smart device and preserves privacy, and data confidentiality of the communicating user. To support our claim, multiple cryptographic attacks are analyzed and found that the proposed scheme is not vulnerable to those attacks. Finally, the computation and communication overheads of the proposed scheme are compared with other existing protocols to confirm that the proposed scheme is lightweight. A formal security analysis using AVISPA simulation tool has been done that confirms the proposed scheme is robust against relevant security threats.

Compact UWB Bandpass Filter With Dual Notch Bands Using Open Circuited Stubs

Abstract: In this letter, an ultra-wideband (UWB) bandpasss filter with multiple notch bands is presented. The UWB bandpass characteristic is achieved using a modified distributed highpass filter (HPF) and suppressing higher order harmonics of the HPF by realizing defected stepped impedance resonator. The dual band notches at 5.75 and 8.05 GHz are obtained by embedding two open stubs on the main microstrip line. The in band and out of band performance obtained from fullwave electromagnetic simulation, equivalent circuit model and measurement are in good agreement.