Department of Computer Science and Information Systems

Permanent URI for this collectionhttp://localhost:4000/handle/123456789/1928

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Start date: 2020Subject: search.filters.subject.Blockchain

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Now showing 1 - 10 of 22
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    An efficient and scalable byzantine fault tolerant consensus for vehicular networks
    (IEEE, 2025) Alladi, Tejasvi
    Vehicular networks represent a new distributed system paradigm that requires robust fault tolerance to ensure reliable operation. As a burgeoning area of research, the scalability and optimization of consensus mechanisms for these networks are critical. Traditional Byzantine Fault Tolerant (BFT) algorithms like PBFT are not inherently optimized for the localized needs of vehicular networks, suffering from scalability issues due to their global nature and high messaging complexity. In response, we introduce a two-tiered consensus framework that refines PBFT for the specific context of vehicular networks. By organizing nodes into clusters based on geographic proximity, our approach reduces messaging complexity from O(n2) to O(n1.5), significantly improving scalability. The framework distinguishes between local and global state transitions, adding two phases to the PBFT protocol to manage these efficiently. This tailored consensus process aligns with the localized communication patterns of vehicular networks, enhancing both efficiency and scalability. The framework addresses the critical challenges of traditional BFT algorithms in vehicular networks, offering a solution that is both scalable and resilient. It is a step toward enabling vehicular networks to fulfil their potential as a reliable component of modern distributed systems.
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    Layered blockchain-based mobile crowdsensing architecture: exploring privacy and scalability challenges across layers
    (Springer, 2025-04) Bhatia, Ashutosh; Tiwari, Kamlesh
    Blockchain technology has emerged as a transformative solution for addressing the limitations of traditional Mobile CrowdSensing (MCS) systems, which rely on centralized architectures. Despite its promise, the integration of blockchain into MCS introduces challenges related to privacy, scalability, and system efficiency. This paper presents a comprehensive layered architecture for enhancing blockchain-based MCS systems (BMCS), focusing on two critical dimensions: privacy and scalability. By categorizing challenges and proposed mitigation strategies, the study explores privacy risks arising from blockchain transparency and evaluates privacy-preserving mechanisms, including zero-knowledge proofs, multiparty computation, and homomorphic encryption, to protect sensitive data in decentralized environments. Scalability constraints, such as limited transaction throughput and resource intensity, are presented with targeted solutions that reduce on-chain loads and improve performance. The findings contribute actionable insights to advance BMCS systems, charting a path for resilient and scalable decentralized ecosystems.
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    Security of Cryptocurrencies in blockchain technology: State-of-art, challenges and future prospects
    (Elsevier, 2020-08) Gupta, Shashank; Dua, Amit
    In contemporary era of technologies, blockchain has acquired tremendous attention from various domains. It has wide spectrum of applications ranging from finance to social services and has greatly influenced the emerging business world. Since, blockchain technology is getting embedded in the e-commerce services, the cryptocurrencies are gaining huge prevalence. Bitcoin and ethereum are few such crypto currencies, which have utilized decentralized nature of blockchain. Blockchain can be considered as a distributed database system containing immutable ledgers, which are prone to attack by malicious users. Although, from the initial digital currency to the present smart contract, the utilities of blockchain have been harnessed, the innovative technology has to rely on cryptography for its security. There are several reports, which emphases on the vulnerabilities and security of blockchain, however, there is a lack of a comprehensive and methodical survey in both application and technical views. In this survey article, the authors cover various aspects related to blockchain including its taxonomies and the situations in which a particular category of blockchain should be applied. The authors also focusses on the structure of blockchain and the working of the ongoing transactions in the cryptocurrency network. In addition, the authors also specify various categories of consensus protocols, smart contracts, forks, techniques for generating the consensus. A detailed taxonomy of blockchain along with their features and related real-world applications is also discussed. In addition, existing key platforms of blockchain related to the cryptocurrencies, hyperledger and multichain are also discussed. Existing emerging vulnerabilities of blockchain related to the recent attacks on bitcoin and etherum is also presented along with the defensive methodologies and future trends in blockchain.
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    A Fast, Secure and Distributed Consensus Mechanism for Energy Trading Among Vehicles using Hashgraph
    (IEEE, 2020) Bhatia, Ashutosh
    Energy trading among inter vehicles (V2V) offers an efficient response to most of the problems presented by future electricity supply. V2V is often envisioned as a peer-to-peer (P2P) model of electric mercantilism for electric vehicle (EV) merchandising. With security vulnerability increasing, confidence in secured third parties is declining. Blockchain is becoming increasingly common as it provides a system for privacy conservation and efficient agreement without the need for trusted third parties. However, all operations in such a scheme are restricted by memory, time, computing capital, energy etc. and it is quite obvious that the mechanism for blockchain agreement is not sufficient to address all of them. In this paper, we present an alternative to the blockchain using Hashgraph which is scalable, fast, fault-tolerant and fair. It is efficient, inexpensive, and DoS resistant fulfilling the requirement of V2V energy trading
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    Securing IoT Applications using Blockchain: A Survey
    (2020-06) Bhatia, Ashutosh
    The Internet of Things (IoT) has become a guiding technology behind automation and smart computing. One of the major concerns with the IoT systems is the lack of privacy and security preserving schemes for controlling access and ensuring the security of the data. A majority of security issues arise because of the centralized architecture of IoT systems. Another concern is the lack of proper authentication and access control schemes to moderate access to information generated by the IoT devices. So the question that arises is how to ensure the identity of the equipment or the communicating node. The answer to secure operations in a trustless environment brings us to the decentralized solution of Blockchain. A lot of research has been going on in the area of convergence of IoT and Blockchain, and it has resulted in some remarkable progress in addressing some of the significant issues in the IoT arena. This work reviews the challenges and threats in the IoT environment and how integration with Blockchain can resolve some of them.
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    E-Governance: A Tendering Framework Using Blockchain With Active Participation of Citizens
    (IEEE, 2020) Bhatia, Ashutosh
    E-governance, i.e., the use of information technology for government activities to provide services, exchange information, etc. are becoming increasingly popular. One such area of e-governance is e-tendering. While e-tendering makes the tendering process more efficient, a trust deficit remains between the citizens and the government, due to the centralized management of the whole tendering process. Several research works provide a decentralized solution to make the process of e-tendering more secure, transparent, and fair. However, in the present time, the government posts the problems/issues currently they are dealing with; and seems interested in taking the suggestions from the citizens to make the better solution for the problem. Thus, in this paper, a permissioned blockchain-based approach to provide a transparent and fair tendering system with citizens' active participation and tracking of funds is presented. In the proposed scheme, the citizens can see the tendering activities transparently and give ideas and suggestions to solve the government's posted problems and receive a due credit of that contribution is a fair manner.
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    Decentralized Online Voting using Blockchain and Secret Contracts
    (IEEE, 2021) Bhatia, Ashutosh
    Voting is a complex process with a lot depending on it. Building an e-voting system that can guarantee anonymity, verifiability, and transparency together is a challenging task. Continuous efforts are being made to improve the voting system to achieve these properties. Recently, blockchain has hit the technology space with many promises, especially to make verifiable and transparent decentralized systems. However, a major challenge faced with blockchain-based e-voting systems is to achieve the users' anonymity while ensuring only authorized voters should be able to vote, and that too only once. To address these issues, this paper proposes a blockchain-based e-voting system with secret contracts. We have used Enigma (a secure multiparty computation platform) to design secret contracts. The proposed system meets most of the features required to conduct free and fair voting electronically.
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    Multi-vendor IoT-based Resource Sharing using OAuth and Blockchain
    (IEEE, 2022) Bhatia, Ashutosh; Tiwari, Kamlesh
    Scarcity of resources is a major problem associated with growing urbanization across the globe. A natural way to address the issue is to share the resources. This solution is not only cost-effective but also sometimes environment friendly. However, sharing resources among people in a trustless environment (in big cities, people do not know each other) and preserving the participant’s privacy are important issues to be addressed. Internet-of-Things and Blockchain together are being considered by the researchers to develop solutions for different smart city applications. In this paper, we propose a privacy preserving blockchain-based framework for multi-vendor IoT-based resource sharing for smart cities. OAuth is integrated with the proposed framework to authorize the blockchain to make the payment from the requester to the service provider. The proposed solution is implemented on the EOS blockchain instead of Ethereum because EOS does not require a fee for executing the smart contract and can conduct millions of transactions per second.
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    DD-Locker: Blockchain-based Decentralized Personal Document Locker
    (IEEE, 2022) Bhatia, Ashutosh
    Document verification is the first step whenever we enter any organization or institute. In any organization, it is essential to track, verify, and check the person’s background who will become a part of the organization. This process is very time-consuming and hectic for both parties involved. Various governments provide cloud-based digital locker services for the citizens storing the public document on a centralized server. But due to its centralized nature, this type of service is weak against information breaches and Denial of Service (DoS) attacks. Also, there are some privacy concerns with such centralized digital locker services as the stored documents may contain users’ crucial personal information. This paper proposes a blockchain-based digital locker in a decentralized application using Ethereum Blockchain to securely store personal documents with high availability. The proposed solution also verifies documents with ease, confidentiality, access control, data privacy, authenticity, and maintaining the integrity of documents.
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    Bitcoin’s Blockchain Data Analytics: A Graph Theoretic Perspective
    (Springer, 2022-03) Bhatia, Ashutosh; Tiwari, Kamlesh
    Bitcoin is the first and most widely used cryptocurrency in the world. It provides a pseudonym identity to its users that is established using the user’s public key, which leads to preserving the user’s privacy. Each transfer of bitcoin cryptocurrency among the users makes a transaction. The pseudonym identities are considered as transaction end-points. These transactions are recorded on an immutable public ledger called Blockchain which is an append-only data structure. The popularity of Bitcoin has increased unreasonably. The general trend shows a positive response from the common masses indicating an increase in trust and privacy concerns which makes an interesting use case from the analysis point of view. Moreover, since the blockchain is publicly available and up-to-date, any analysis would provide a live insight into the usage patterns which ultimately would be useful for making a number of inferences by law-enforcement agencies, economists, tech-enthusiasts, etc. In this paper, we study various applications and techniques of performing data analytics over Bitcoin blockchain from a graph theoretic perspective. We also propose a framework for performing such data analytics and explored a couple of use cases using the proposed framework.