Compress-store on blockchain: a decentralized data processing and immutable storage for multimedia streaming

Decentralization for data storage is a challenging problem for blockchain-based solutions as the blocksize plays a key role for scalability. In addition, specific requirements of multimedia data call for various changes in the blockchain technology internals. Considering one of the most popular applications of secure multimedia streaming, i.e., video surveillance, it is not clear how to judiciously encode incentivization, immutability, and compression into a viable ecosystem. In this study, we provide a genuine scheme that achieves this encoding for a video surveillance application. The proposed scheme provides a novel integration of data compression, immutable off-chain data storage using a new consensus protocol namely, Proof-of-WorkStore (PoWS) in order to enable fully useful work to be performed by the miner nodes of the network. The proposed idea is the first step towards achieving greener application of a blockchain-based environment to the video storage business that utilizes system resources efficiently.WOS:000773171200001Scopus - Affiliation ID: 60105072Science Citation Index ExpandedQ2 - Q4Article; Early AccessUluslararası işbirliği ile yapılan - EVETNisan2022YÖK - 2021-22Mar

Blockchain technology to secure data for digital twins throughout smart buildings’ life cycle in the context of the circular economy

Blockchain technology (BCT) can be leveraged for digital twins (DT) to enhance data security, collaboration, efficiency, and sustainability in the construction industry (CI) 4.0. This study aims to develop a novel technological framework and software architecture using BCT for DT throughout the lifecycle of smart building projects in the context of the circular economy (CE). The study identifies key challenges and technological factors affecting BCT adoption. It also identifies which project data types can benefit from BCT and the key factors and non-functional requirements (NFRs) necessary for the adoption of blockchain based digital twins (BCDT) in CI 4.0. The study finally proposes a software architecture and smart contract framework for BCDT decentralized applications (DApps) throughout the lifecycle of smart infrastructure projects. The study offers a technological framework – the decentralized digital twin cycle (DDTC) – with BCT to enhance trust, security, decentralization, efficiency, traceability, and transparency of information. The study found that the key data from the project lifecycle relevant for BCDTs relate to the BIM dimensions (3D, 4D, 5D, 6D, 7D, and 8D) and a novel contractual dimension (cD) is also proposed. Additionally, BCDT maturity Level 4 is proposed, leveraging BCT to enhance collaboration, process automation, and data sharing within a decentralized data value chain. The main NFRs for BCDTs are security, privacy, interoperability, data ownership, data integrity, and the decentralization and scalability of data storage. A five layered software architecture and a smart contracts framework using Non-Fungible Tokens (NFTs) are offered to address key industry use cases and their functional and non-functional requirements. The framework narrows the gaps identified around network governance, scalability, decentralization, interoperability, energy efficiency, computational requirements, and the integration of BCT with IoT, BIM, and DT. A cost analysis permitted developing criteria to evaluate the suitability of blockchain networks for BCDT applications in CI 4.0 based on key blockchain properties (security, decentralization, scalability, and interoperability). The study provides an industry-specific analysis and technological approach for BCDT adoption to address key challenges and improve sustainability for the CI 4.0. The findings provide key building blocks for industry practitioners to adopt and develop BCDT DApps further. The framework enables a paradigm shift towards decentralized ecosystems of united BCDTs where trust, collaboration, data sharing, information security, efficiency, and sustainability are improved throughout the lifecycle of smart infrastructure projects within a decentralized CE (DCE)

FAST DATA: A Fair, Secure and Trusted Decentralized IIoT Data Marketplace enabled by Blockchain

As the world calls it, data is the new oil. With vast installments of Industrial Internet-of-Things (IIoT) infrastructure, data is produced at a rate like never before. Similarly, artificial intelligence (AI) and machine learning (ML) solutions are getting integrated to numerous services, making them "smarter". However, the data remains fragmented in individual organizational silos inhibiting data value extraction to it’s full potential. Digital marketplaces are emerging to allow data owners to monetize this data. Yet concerns like privacy, security and unfair payment settlement deter adoption of such platforms. In addition, the state-of-the-art platforms are under the control of large multinational corporations with no transparency between buyer and seller in terms of payment details, listing, data discovery and storage. In this work, a novel decentralized platform of digital data marketplace for IoT data has been proposed. The platform leverages a decentralized data streaming network to host IoT data in a reliable and fault tolerant manner. The platform ensures fair trading, data storage and delivery in a privacy preserving manner and trust metric calculation for actors in the network. In order to study the feasibility of the proposed platform, an open source library is developed using Hyperledger Fabric and data network layer built on VerneMQ, the library is deployed on a real-time Google cloud platform. The library is tested and results are analysed for throughput, overheads and scalability

Tag-assisted social-aware opportunistic device-to-device sharing for traffic offloading in mobile social networks

Within recent years, the service demand for rich multimedia over mobile networks has kept being soaring at a tremendous pace. To solve the critical problem of mobile traffic explosion, substantial efforts have been made from researchers to try to offload the mobile traffic from infrastructured cellular links to direct short-range communications locally among nearby users. In this article, we discuss the potential of combining users’ online and offline social impacts to exploit the device-to-device (D2D) opportunistic sharing for offloading the mobile traffic. We propose Tag-Assisted Social-Aware D2D sharing framework, TASA, with corresponding optimization models, architecture design, and communication protocols. Through extensive simulations based on real data traces, we demonstrate that TASA can offload up to 78.9% of the mobile traffic effectively

Blockchain based energy transactions for a prosumer community

PhD thesis in Information technologyIntegration of solar micro-generation capabilities in domestic contexts is on the rise, leading to the creation of prosumer communities who generate part of the energy they consume. Prosumer communities require a decentralized, transparent and immutable transaction system in order to extract value from their surplus energy generation and usage flexibility. The aim of this study is to develop frameworks and methods to create such a prosumer transaction system with self enforcing smart contracts to facilitate trading of energy assets such as electricity units, energy flexibility incentives and storage credits. Blockchain is a transparent, distributed ledger for consensus based transaction processing maintained by a network of peer nodes. Hyperledger Fabric is a blockchain platform that offers the added benefits of lower operating cost, faster transaction processing, user authentication based access control and support for self enforcing smart contracts. This thesis investigates the applicability of Hyperledger Fabric to tokenize and transact energy assets in a unified transaction system. Data driven approaches to implement an incentive based energy flexibility system for peak mitigation on the blockchain are also investigated. To this end, the stakeholders for such a transaction management system were identified and their business relationships and interactions were described. Energy assets were encapsulated into blockchain tokens and algorithms were developed and encoded into self enforcing smart contracts based on the stakeholder relationships. A unified transaction framework was proposed that would bring on board all the stakeholders, their trading relationships and the assets being transacted. Tokens and methods in the transaction system were implemented in fungible and non fungible versions and the versions were critically compared in terms of application area, design, algorithmic complexity, performance, advantages and disadvantages. Further, with a focus on energy flexibility applications, a prosumer research dataset was analysed to gain insights into the production and consumption behaviors. Based on these insights, a data driven approach for peak mitigation was proposed and implemented on the Hyperledger Fabric blockchain. The thesis thus addresses different aspects of a blockchain based prosumer transaction system, and shows the feasibility of proposed approaches through implementation and performance testing of proofs of concept