Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Rao, V.

Search Results

Now showing 1 - 6 of 6
  • No Thumbnail Available
    Item
    Ethereum Blockchain Enabled Secure and Transparent E-Voting
    (Springer Science and Business Media Deutschland GmbH, 2021) Rao, V.; Singh, A.; Rudra, B.
    The blockchain’s revolutionary concept is the underlying technology behind the popular examples such as Bitcoin and it now relies on the Web and online services. Nowadays, blockchain is famous for its use in cryptocurrencies, but many fintech activities and routine processes that were done offline can be done using blockchain. Smart contracts are abstract pieces of codes that need to be inserted into the network and enforced as planned in every phase of upgrading blockchains. With the population growing so fast across the globe, e-voting is an emerging online service-related issue. The smart contracts of blockchain enable to have a easy, safe, cheap, secure and transparent e-voting due to which blockchain is one of the top solutions for e-voting. Even in the many blockchains available in the world, Ethereum is one of the most consistent available blockchain and has widespread use because of which it is suitable for e-voting. An e-voting system must ensure that it is secure, as it should not allow duplicated votes and it should be able to protect attendants’ privacy being fully transparent too. In this paper, Ethereum wallets and Solidity language for smart contracts were used to make a sample small scale e-voting application. The blockchain was tested on local blockchain using ganache and ropsten test network. The Ethereum blockchain keeps the records of ballots and votes after an election is held. Users can use Ethereum wallets to directly submit theirs vote and those votes are handled with the consensus of each Ethereum node. © 2021, Springer Nature Switzerland AG.
  • No Thumbnail Available
    Item
    Efficient PBFT: A Novel and Efficient Approach to the PBFT Consensus Algorithm
    (Springer Science and Business Media Deutschland GmbH, 2022) Rao, V.; Shenoy, A.R.; Manjappa, M.
    Blockchain technology, which is built upon the distributed and decentralised network, suffers from mutual trust among the nodes, and hence, it employs a consensus algorithm to achieve democracy. Consensus algorithm is one of the core elements of blockchain architecture, and a strong, reliable and efficient consensus algorithm is very much required for a blockchain network in order to prevent the intrusion of malicious nodes. A good consensus algorithm drives the blockchain network in the right direction by keeping the malicious transactions off the chain. Thus, in this article, a novel consensus algorithm referred to as efficient practical Byzantine fault tolerance (E-PBFT) is proposed for a private blockchain. E-PBFT finds the winner miner for mining the candidate blocks in an efficient manner which reduces the number of messages exchanged between the nodes. Further, in order to give additional security, a hidden winner miner concept is also included in E-PBFT which hides the winner miner from the adversaries, so that the adversaries will never come to know who is mining the transactions. The theoretical proof for the proposed algorithm is also given whose results are quite convincing when compared to classical PBFT algorithm. The proposed E-PBFT will definitely strengthen the blockchain network by quickly reaching the consensus and by hiding the winner miner, thereby giving additional security. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
  • No Thumbnail Available
    Item
    Synthesis, characterization and studies on the nonlinear optical parameters of hydrazones
    (2010) Naseema, K.; Sujith, K.V.; Manjunatha, K.B.; Kalluraya, B.; Umesh, G.; Rao, V.
    Three hydrazones, 2-(4-methylphenoxy)-N?-[(1E)-(4-nitrophenyl)methylene]acetohydrazide (compound-1), 2-(4-methylphenoxy)-N?-[(1E)-(4-methylphenyl)methylene]acetohydrazide ((compound-2) and N?-{(1E)-[4-(dimethylamino)phenyl]methylene}-2-(4-ethylphenoxy) acetohydrazide(compound-3) were synthesized and their third order nonlinear optical properties were investigated using a single beam z-scan technique with nanosecond laser pulses at 532 nm. Open aperture data obtained from the three compounds indicates two photon absorption at this wavelength. The nonlinear refractive index n2, the nonlinear absorption coefficient ?, the magnitude of the effective third order susceptibility ?(3), the second order hyperpolarizability ?h and the coupling factor ? have been estimated. The values obtained are comparable with the values obtained for 4-methoxy chalcone derivatives and dibenzylidene acetone derivatives. Among the compounds studied, compounds-1 and 3 exhibited the better optical power limiting behaviour at 532 nm. Our studies suggest that compounds-1, 2 and 3 are potential candidates for optical device applications such as optical limiters and optical switches. © 2009 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Synthesis, characterization and studies on nonlinear optical parameters of 4-amino-5-(4-nitrophenyl)-1, 2, 4-triazole-3-thione
    (2010) Naseema, K.; Rao, V.; Manjunatha, K.B.; Umesh, G.; Sujith, K.V.; Kalluraya, B.
    In this paper, we report the synthesis, characterization and third order nonlinear optical properties of a new organic NLO material of 4-amino-5-(4-nitrophenyl)-1, 2, 4-triazole-3-thione (ANIT). The material was characterized by UV-vis and FTIR studies. The third order nonlinear optical properties have been investigated in dimethyl formamide (DMF) solution at 532 nm by using the Z-scan technique with pulses of nanoseconds duration. Open aperture data demonstrates the presence of two photon absorption at this wavelength. The nonlinear absorption coefficient ?, the nonlinear refractive index n2, the magnitude of effective third order susceptibility ?(3) and the second order hyperpolarizability ?h have been estimated as 2.99 cm/GW, -2. 53?×?10-11 esu, 2.72?×?10 -13esu and 0.281?×?10-31esu respectively. The values obtained are comparable with the values obtained for 4-methoxy chalcone derivatives and dibenzylideneacetone derivatives. The value of coupling factor have been estimated to be 0.17, indicating that the nonlinearity is electronic in origin. The compound exhibits good optical limiting at 532 nm with the limiting threshold of 80 ?J/pulse. The comparatively high value obtained indicates that this material may be used in optical device applications like optical limiters and optical switches. © 2010 Optical Society of India.
  • No Thumbnail Available
    Item
    ?(3) measurement and optical limiting studies of urea picrate
    (2011) Naseema, K.; Shyma, M.; Manjunatha, K.B.; Muralidharan, A.; Umesh, G.; Rao, V.
    The molecular charge complex urea picrate (UP) was synthesized and its third order nonlinear optical properties have been investigated using a single beam Z-scan technique with nanosecond laser pulses at 532 nm. Open aperture data of the compound indicates two photon absorption at this wavelength. The nonlinear refractive index n2, nonlinear absorption coefficient ?, magnitude of effective third order susceptibility ?(3), the second order hyperpolarizability ?h and the coupling factor ? have been estimated. The experimentally determined values of ?, n2, Re ?(3) and Im ?(3), ?h and ? of the compound UP are 2.146 cm/GW, -1.258×10-11 esu, -1.347×10-13 esu, 0.377×10-13 esu, 0.69×10-32 esu and 0.28, respectively. The compound exhibits good optical limiting at 532 nm with the limiting threshold of 80 ?J/pulse. Our studies suggest that compound UP is a potential candidate for optical device applications such as optical limiters. © 2011 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Third order optical nonlinearity and optical limiting studies of propane hydrazides
    (Elsevier B.V., 2012) Naseema, K.; Manjunatha, K.B.; Sujith, K.V.; Umesh, G.; Kalluraya, B.; Rao, V.
    Four hydrazones, 2-(4-isobutylphenyl)-N?-[phenylmethylene] propanehydrazide (P1), 2-(4-isobutylphenyl)-N?-[(4- tolyl)methylene] propane hydrazide (P2), 2-(4-isobutylphenyl)- N?-[1-(4- chlorophenyl)ethylidene] propanehydrazide (P3) and 2-(4-isobutylphenyl)-N?-[1-(4-Nitrrophenyl)ethylidene] propane hydrazide (P4) were synthesized and their third order nonlinear optical properties have been investigated using a single beam Z-scan technique with nanosecond laser pulses at 532 nm. The measurement on the compound-P1 is not reported as there is no detectable nonlinear response. Open aperture data of the other three compounds indicate two photon absorption at this wavelength. The nonlinear refractive index n2, nonlinear absorption coefficient ?, magnitude of effective third order susceptibility ?(3), the second order hyperpolarizability ?h and the coupling factor ? have been estimated. The values obtained are comparable with the values obtained for 4-methoxy chalcone derivatives and dibenzylideneacetone derivatives. The experimentally determined values of ?, n2, Re ?(3) and Im ?(3), ?h and ? of the compound-P4 are 1.42 cm/GW, -0.619 × 10-11 esu, -0.663 × 10-13 esu, 0.22 × 10-13 esu, 0.34 × 10-32 esu and 0.33 respectively. Further the compound-P4 exhibited the best optical power limiting behavior at 532 nm among the compounds studied. Our studies suggest that compounds P2, P3 and P4 are potential candidates for the optical device applications such as optical limiters and optical switches. © 2012 Elsevier B.V. All rights reserved.