Indian Institute of Technology Kharagpur

About: Indian Institute of Technology Kharagpur is a education organization based out in Kharagpur, India. It is known for research contribution in the topics: Computer science & Dielectric. The organization has 16887 authors who have published 38658 publications receiving 714526 citations.

A secure user anonymity-preserving biometric-based multi-server authenticated key agreement scheme using smart cards

Abstract: Advancement in communication technology provides a scalable platform for various services, where a remote user can access the server from anywhere without moving from its place. It provides a unique opportunity for online services such that a user does not need to be physically present at the service center. These services adopt authentication and key agreement protocols in order to ensure authorized and secure access to the resources. Most of the authentication schemes proposed in the literature support a single-server environment, where the user has to register with each server. If a user wishes to access multiple application servers, he/she requires to register with each server. The multi-server authentication introduces a scalable platform such that a user can interact with any server using single registration. Recently, Chuang and Chen proposed an efficient multi-server authenticated key agreement scheme based on a user’s password and biometrics (Chuang and Chen, 2014). Their scheme is a lightweight, which requires the computation of only hash functions. In this paper, we first analyze Chuang and Chen’s scheme and then identify that their scheme does not resist stolen smart card attack which causes the user’s impersonation attack and server spoofing attack. We also show that their scheme fails to protect denial-of-service attack. We aim to propose an efficient improvement on Chuang and Chen’s scheme to overcome the weaknesses of their scheme, while also retaining the original merits of their scheme. Through the rigorous informal and formal security analysis, we show that our scheme is secure against various known attacks including the attacks found in Chuang and Chen’s scheme. Furthermore, we simulate our scheme for the formal security verification using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool and show that our scheme is secure against the replay and man-in-the-middle attacks. In addition, our scheme is comparable in terms of the communication and computational overheads with Chuang and Chen’s scheme and other related existing schemes.

Preparation and properties of nanocomposites based on acrylonitrile-butadiene rubber, styrene-butadiene rubber, and polybutadiene rubber

Abstract: Nanocomposites were prepared with different grades of nitrile rubber with acrylonitrile contents of 19, 34, and 50%, with styrene–butadiene rubber (23% styrene content), and with polybutadiene rubber with Na-montmorillonite clay. The clay was modified with stearyl amine and was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The XRD studies showed an increase in the gallery gap upon the modification of the filler by stearyl amine. The intercalation of the amine chains into the clay gallery gap was confirmed by the presence of some extra peaks (2928, 2846, and 1553 cm−1) in the FTIR spectra. The clay–rubber nanocomposites were characterized by TEM and XRD. The mechanical properties were studied for all the compositions. An improvement in the mechanical properties with the degree of filler loading up to a certain level was observed. The changes in the mechanical properties, with changes in the nature and polarity of the rubbers, were explained with the help of XRD and TEM results. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1573–1585, 2004

Analysis and modeling of fixed bed column operations on As(V) removal by adsorption onto iron oxide-coated cement (IOCC).

Abstract: Fixed-bed column studies were undertaken to evaluate the performance of iron oxide-coated cement (IOCC) in removing As(V), from aqueous environment, under varying operating conditions. Investigations revealed IOCC to be a very efficient media for the removal of As(V) from water. The Bohart and Adams sorption model was employed to determine characteristic parameters such as depth of exchange zone, time required for exchange zone to move its own height, adsorption rate, and adsorption capacity, useful for process design. The IOCC media effectively removed As(V) from a 2 mg/L solution with a maximum adsorption capacity of 505.3 mg/L. Predicted data points obtained using a Freundlich isotherm model were compared against experimental data points determined in the dynamic process. The effects of important design parameters such as flow rate and influent concentration on the As(V) breakthrough curves were also investigated. The bed depth service time (BDST) model was extended to the prediction of service times of columns operated at different flow rates and influent concentrations and these predicted values were compared with the experimental values. The columns were regenerated by eluting the bound As(V) with 10% NaOH after the adsorption studies.