Abstract

In this paper, we devise a new and efficient biometric-based password authentication scheme (BIO-PWA) for the client-server environment. Our scheme uses the elliptic curve cryptography (ECC) along with the fuzzy extractor. Through the rigorous security analysis, we show that our scheme is secure against various known attacks. We further show that our scheme is secure in the generic group model through the formal security analysis. In addition, the formal security verification of our scheme using the widely-accepted automated validation of internet security protocols and applications (AVISPA) tool is performed against active and passive adversaries and the simulation results clearly demonstrate that our scheme is secure against active and passive attacks, including the replay and man-in-the-middle attacks. Finally, we show that our scheme is also efficient in computation against the existing related ECC-based authentication schemes for the client-server environment.

Abstract

In recent years, Voice over Internet Protocol (VoIP) has gained more and more popularity as an application of the Internet technology. For various IP applications including VoIP, the topic of Session Initiation Protocol (SIP) has attracted major concern from researchers. SIP is an advanced signaling protocol operating on Internet Telephony. SIP uses digest authentication protocols such as Simple Mail Transport Protocol (SMTP) and HyperText Transport Protocol (HTTP). When a user seeks SIP services, authentication plays an important role in providing secure access to the server only to the authorized access seekers. Being an insecure-channel-based protocol, a SIP authentication protocol is susceptible to adversarial threats. Therefore, security is a big concern in SIP authentication mechanisms. This paper reveals the security vulnerabilities of two recently proposed SIP authentication schemes for VoIP, Irshad et al.’s scheme [Multimed. Tools. Appl. doi:10.1007/s11042-013- 1807-z] and Arshad and Nikooghadam’s scheme [Multimed. Tools. Appl. DOI 10.1007/ s11042-014-2282-x], the later scheme is based on the former scheme. Irshad et al.’s scheme suffers from password guessing, user impersonation and server spoofing attacks. Arshad and Nikooghadam’s scheme can be threatened with server spoofing and stolen verifier attack. None of these two schemes achieve mutual authentication. It also fails to follow the single round-trip authentication design of Irshad et al.’s scheme. To overcome these weaknesses, we propose a provable secure single round-trip SIP authentication scheme for VoIP using smart card. We formally prove the security of the scheme in random oracle and demonstrate through discussion its resistance to various attacks. The comparative analysis shows that the proposed SIP authentication scheme offers superior performance with a little extra computational cost.

Abstract

Recently, in 2014, He and Wang proposed a robust and efficient multi-server authentication scheme using biometrics-based smart card and elliptic curve cryptography (ECC). In this paper, we first analyze He-Wang's scheme and show that their scheme is vulnerable to a known session-specific temporary information attack and impersonation attack. In addition, we show that their scheme does not provide strong user's anonymity. Furthermore, He-Wang's scheme cannot provide the user revocation facility when the smart card is lost/stolen or user's authentication parameter is revealed. Apart from these, He-Wang's scheme has some design flaws, such as wrong password login and its consequences, and wrong password update during password change phase. We then propose a new secure multi-server authentication protocol using biometric-based smart card and ECC with more security functionalities. Using the Burrows-Abadi-Needham logic, we show that our scheme provides secure authentication. In addition, we simulate our scheme for the formal security verification using the widely accepted and used automated validation of Internet security protocols and applications tool, and show that our scheme is secure against passive and active attacks. Our scheme provides high security along with low communication cost, computational cost, and variety of security features. As a result, our scheme is very suitable for battery-limited mobile devices as compared with He-Wang's scheme.

Abstract

Traditional association rule mining based on the support–confidence framework provides the objective measure of the rules that are of interest to users. However, it does not reflect the semantic measure among the items. The semantic measure of an itemset is characterized with utility values that are typically associated with transaction items, where a user will be interested to an itemset only if it satisfies a given utility constraint. In this paper, we first define the problem of finding association rules using utility-confidence framework, which is a generalization of the amount-confidence measure. Using this semantic concept of rules, we then propose a compressed representation for association rules having minimal antecedent and maximal consequent. This representation is generated with the help of high utility closed itemsets (HUCI) and their generators. We propose the algorithms to generate the utility based non-redundant association rules and methods for reconstructing all association rules. Furthermore, we describe the algorithms which generate high utility itemsets (HUI) and high utility closed itemsets with their generators. These proposed algorithms are implemented using both synthetic and real datasets. The results demonstrate better efficiency and effectiveness of the proposed HUCI-Miner algorithm compared to other well-known existing algorithms. In addition, the experimental results show better quality in the compressed representation of the entire rule set under the considered framework.

Abstract

Structural bioinformatics of RNA has evolved mainly in response to the rapidly accumulating evidence that non-(protein)-coding RNAs (ncRNAs) play critical roles in gene regulation and development. The structures and functions of most ncRNAs are however still unknown. Most of the available RNA structural databases rely heavily on known 3D structures, and contextually correlate base pairing geometry with actual 3D RNA structures. None of the databases provide any direct information about stabilization energies. However, the intrinsic interaction energies of constituent base pairs can provide significant insights into their roles in the overall dynamics of RNA motifs and structures. Quantum mechanical (QM) computations provide the only approach toward their accurate quantification and characterization. ‘RNA Base Pair Count, Geometry and Stability’ ( http://bioinf.iiit.ac.in/RNABPCOGEST …

Abstract

The roles of protonated nucleobases in stabilizing different structural motifs and in facilitating catalytic functions of RNA are well known. Among different polar sites of all the nucleobases, N7 of guanine has the highest protonation propensity at physiological pH. However, unlike other easily protonable sites such as N1 and N3 of adenine or N3 of cytosine, N7 protonation of guanine does not lead to the stabilization of base pairs involving its protonated Hoogsteen edge. It also does not facilitate its participation in any acid–base catalysis process. To explore the possible roles of N7 protonated guanine, we have studied its base pairing potentials involving WatsonCrick and sugar edges, which undergo major charge redistribution upon N7 protonation. We have carried out quantum chemical geometry optimization at the M05-2X/6-311G+(2d,2p) level, followed by interaction energy calculation at the MP2/aug-cc-pVDZ

Abstract

Improving the thermostability of industrial enzymes is an important protein engineering challenge. Point mutations, induced to increase thermostability, affect the structure and dynamics of the target protein in several ways and thus can also affect its activity. There appears to be no general rules for improving the thermostabilty of enzymes without adversely affecting their enzymatic activity. We report MD simulations, of wild type Bacillus subtilis lipase (WT) and its six progressively thermostable mutants (2M, 3M, 4M, 6M, 9M, and 12M), performed at different temperatures, to address this issue. Less thermostable mutants (LTMs), 2M to 6M, show WT-like dynamics at all simulation temperatures. However, the two more thermostable mutants (MTMs) show the required flexibility at appropriate temperature ranges and maintain conformational stability at high temperature. They show a deep and rugged free-energy

Abstract

Drought is one of the major environmental stress conditions affecting the yield of rice across the globe. Unraveling the functional roles of the drought-responsive genes and their underlying molecular mechanisms will provide important leads to improve the yield of rice. Co-expression relationships derived from condition-dependent gene expression data is an effective way to identify the functional associations between genes that are part of the same biological process and may be under similar transcriptional control. For this purpose, vast amount of freely available transcriptomic data can be used for functional annotation. In this study we consider gene expression data for different tissues and developmental stages in response to drought stress. We analyze the network of co-expressed genes to identify drought-responsive genes modules in a tissue and stage-specific manner based on differential expression and gene enrichment analysis. Taking cues from the systems-level behavior of these modules, we propose two approaches to identify clusters of tightly co-expressed/co-regulated genes. Using graph-centrality measures and differential gene expression, we identify biologically informative genes that lack any functional annotation. We show that using orthologous information from other plant species, the conserved co-expression patterns of the uncharacterized genes can be identified. Presence of a conserved neighborhood enables us to extrapolate functional annotation. Alternatively, we show that ‘guide-gene’ approach can help in understanding the tissue-specific transcriptional regulation of uncharacterized genes. Finally, we confirm the …

Abstract

In the last decade there has been considerable interest in a novel dynamical phenomenon of chimera states observed in an array of non-locally coupled oscillators where regions of coherence and incoherence coexist across the network. In this study we show how chimera states emerge in coupled logistic maps for certain specified initial conditions when the range and strength of coupling is varied. Here we show that these states are very robust and persist even in the presence of noise in the network parameters. On applying localized external perturbation to the incoherent regions, it is possible to obtain a completely coherent/incoherent dynamics in the whole network depending on the strength and sign of perturbation. This has important applications in the control of undesirable local dynamics, such as seizures in neural systems, or fibrillations in cardiac

Abstract

The current study evaluates the growing stock, biomass and carbon content of Andhra Pradesh state’s forest (India) along with its current status of forest degradation and loss. For this purpose, the study used the growing stock data collected by state forest department in 2010 for the calculation of biomass and carbon storage using the standard conversion and expansion factors given by IPCC. The analysis shows low biomass and carbon values for the state’s forest in comparison to the mean values recorded in different studies made for Andhra Pradesh. It is also observed to be lower when compared with the average carbon and biomass for Indian forests. Overall, the analysis showed degradation and loss of forest in the state, coupled with reduction in biomass and carbon sink.