Abstract

Remote user authentication without compromising user anonymity is an emerging area in the last few years. In this paper, we propose a new anonymity preserving mobile user authentication scheme for the global mobility networks (GLOMONETs). We also propose a new anonymity preserving group formation phase for roaming services in GLOMONETs that meets the extended anonymity requirement without compromising any standard security requirements. We provide the security analysis using the widely-accepted Burrows-Abadi-Needham logic and informal analysis for the proposed scheme to show that it is secure against possible well-known attacks, such as replay, man-in-the-middle, impersonation, privileged-insider, stolen smart card, ephemeral secret leakage, and password guessing attacks. In addition, the formal security verification with the help of the broadly accepted automated validation of internet security protocols and applications software simulation tool is tested on the proposed scheme and the simulation results confirm that the proposed scheme is safe. Moreover, the comparative study of the proposed scheme with other relevant schemes reveals that it performs well as compared to other techniques.

Abstract

Graph algorithms play an important role in several fields of sciences and engineering. Prominent among them are the All-Pairs-Shortest-Paths (APSP) and related problems. Indeed there are several efficient implementations for such problems on a variety of modern multi- and manycore architectures. It can be noticed that for several graph problems, parallelism offers only a limited success as current parallel architectures have severe short-comings when deployed for most graph algorithms. At the same time, some of these graphs exhibit clear structural properties due to their sparsity. This calls for particular solution strategies aimed at scalable processing of large, sparse graphs on modern parallel architectures. In this paper, we study the applicability of an ear decomposition of graphs to problems such as all-pairs-shortest-paths and minimum cost cycle basis. Through experimentation, we show that the resulting solutions are scalable in terms of both memory usage and also their speedup over best known current implementations. We believe that our techniques have the potential to be relevant for designing scalable solutions for other computations on large sparse graphs.

Abstract

Mobile cloud computing (MCC) allows mobile users to have on-demand access to cloud services. A mobile cloud model helps in analyzing the information regarding the patients' records and also in extracting recommendations in healthcare applications. In MCC, a fine-grained level access control of multiserver cloud data is a prerequisite for successful execution of end-users applications. In this paper, we propose a new scheme that provides a combined approach of fine-grained access control over cloud-based multiserver data along with a provably secure mobile user authentication mechanism for the Healthcare Industry 4.0. To the best of our knowledge, the proposed scheme is the first to pursue fine-grained data access control over multiple cloud servers in a MCC environment. The proposed scheme has been validated extensively in different heterogeneous environment where its performance was found good in comparison to other existing schemes.

Abstract

We have applied PLSR on NIRS data of Sorghum to select significant wavelengths for Crude-Protein content. Calibration models proposed using single wavelength (1449nm) and a pair (1485nm and 1486nm) give the coefficient of determination (R 2 ) as 0.7928 and 0.8334 respectively.

Abstract

Security and privacy are the major concerns in cloud computing as users have limited access on the stored data at the remote locations managed by different service providers.These become more challenging especially for the data generated from the wearable devices as it is highly sensitive and heterogeneous in nature. Most of the existing techniques reported in the literature are having high computation and communication costs and are vulnerable to various known attacks, which reduce their importance for applicability in real-world environment. Hence, in this paper, we propose a new cloud based user authentication scheme for secure authentication of medical data. After successful mutual authentication between a user and wearable sensor node, both establish a secret session key that is used for future secure communications. The extensively-used Real-Or-Random (ROR) model based formal security analysis and the broadly-accepted Automated Validation of Internet Security Protocols and Applications (AVISPA) tool based formal security verification show that the proposed scheme provides the session-key security and protects active attacks. Theproposed scheme is also informally analyzed to show its resilience against other known attacks. Moreover, we have done a detailed comparative analysis for the communication and computation costs along with security and functionality features which proves its efficiency in comparison to the other existing schemes of its category.

Abstract

We have analysed the effect of beam wander, jitter and boresight on the deviation of centroid of laser beam. It is seen to be wandering over a restricted range, though off the center of detector.

Abstract

Research has proven that accomplishing security properties while improving performance of an authentication protocol is a challenging task. Numerous authentication protocols proposed in the recent times are still behind in achieving the concrete objectives. Qi et al. and Lu et al. recently proposed two-factor authenticated key-agreement protocols for client–server architecture. This paper revisits their protocols and analyzes the shortcomings of such approaches. We also propose an improved authenticated key agreement protocol for client–server environment to defeat mentioned weaknesses of existing protocols that are discussed in related works. The rigorous security analysis using Burrows–Abadi–Needham logic, formal security verification using Real-OR-Random model, simulations using the Automated Validation of Internet Security Protocols and Applications tool, and the informal security analysis shows that the proposed protocol is secure. Additionally, we summarize the results to ensure that the proposed protocol is efficient compared to the existing related protocols.

Abstract

Authentication schemes are widely used mechanisms to thwart unauthorized access of resources over insecure networks.Several smart card based password authentication schemes have been proposed in the literature. In this paper, we demonstrate the security limitations of a recently proposed password based authentication scheme, and show that their scheme is still vulnerable to forgery and offline password guessing attacks and it is also unable to provide user anonymity, forward secrecy and mutual authentication. With the intention of fixing the weaknesses of that scheme, we present a secure authentication scheme. We show that the proposed scheme is invulnerable to various attacks together with attacks observed in the analyzed scheme through both rigorous formal and informal security analysis. Furthermore, the security analysis using the widely-accepted Real-Or-Random (ROR) model ensures that the proposed scheme provides the session key (SK) security. Finally,we carry out the performance evaluation of the proposed scheme and other related schemes, and the result favors that the proposed scheme provides better trade-off among security and performance as compared to other existing related schemes.

Abstract

With the increasing use of mobile devices, a secure communication and key exchange become the significant security issues in mobile environments. However, because of open network envi-ronments, mobile user can be vulnerable to various attacks. Therefore, the numerous authentication and key exchange schemes have been proposed to provide the secure communication and key exchange.Recently, Qi and Chen proposed an efficient two-party authentication key exchange protocol for mobile environments in order to overcome the security weaknesses of the previous authentication and key exchange schemes. However, we demonstrate that Qi and Chen’s scheme is vulnerable to various attacks such as impersonation, offline password guessing, password change, and privileged insider attacks. We also show that Qi and Chen’s scheme does not provide anonymity, efficient password change mechanism, and secure mutual authentication. In this paper, to overcome the outlined above mentioned security vulnerabilities,we propose a secure and efficient two-party authentication key exchange protocol, called 2PAKEP, that hides user’s real identity from an adversary using a secret parameter. 2PAKEP also withstands various attacks, guarantees anonymity, and provides efficient password change mechanism and secure mutual authentication. In addition, we prove that 2PAKEP provides the secure mutual authentication using the broadly accepted Burrows–Abadi–Needham logic and the session key security using the formal security analysis under the widely accepted real-or-random model. Moreover, the formal security verification using the popular simulated software tool, Automated Validation of Internet Security Protocols and Applications,on 2PAKEP shows that the replay and man-in-the-middle attacks are protected. In addition, we also analyze the performance and security and functionality properties of 2PAKEP and compare these with the related existing schemes. Overall, 2PAKEP provides better security and functionality features, and also the communication and computational overheads are comparable with the related schemes. Therefore, 2PAKEPis applicable to mobile environment efficiently.

Abstract

Steerability is a characteristic non-local trait of quantum states lying in between entanglement and Bell non-locality. A given quantum state is considered to be steerable if it violates a suitably chosen steering inequality. A quantum state which otherwise satisfies a certain inequality can violate the inequality under a global change of basis, i.e., if the state is transformed by a non-local unitary operation. Intriguingly, there are states which preserve their non-violation (pertaining to the said inequality) under any global unitary operation. The present work explores the effect of global unitary operations on the steering ability of a quantum state which lives in two qubits. We characterize such states in terms of a necessary and sufficient condition on their spectrum. Such states are also characterized in terms of some analytic characteristics of the set to which they belong. Looking back at steerability the present work also provides a relation between steerability and quantum teleportation together with the derivation of a result related to the optimal violation of steering inequality. An analytic estimation of the size of such non-violating states in terms of purity is also obtained. Interestingly, the estimation in terms of purity also gives a necessary and sufficient condition in terms of Bloch parameters of the state. Illustrations from some signature class of quantum states further underscore our observations.