When energy trading meets blockchain in electrical power system: The state of the art

With the rapid growth of renewable energy resources, energy trading has been shifting from the centralized manner to distributed manner. Blockchain, as a distributed public ledger technology, has been widely adopted in the design of new energy trading schemes. However, there are many challenging issues in blockchain-based energy trading, e.g., low efficiency, high transaction cost, and security and privacy issues. To tackle these challenges, many solutions have been proposed. In this survey, the blockchain-based energy trading in the electrical power system is thoroughly investigated. Firstly, the challenges in blockchain-based energy trading are identified and summarized. Then, the existing energy trading schemes are studied and classified into three categories based on their main focuses: energy transaction, consensus mechanism, and system optimization. Blockchain-based energy trading has been a popular research topic, new blockchain architectures, models and products are continually emerging to overcome the limitations of existing solutions, forming a virtuous circle. The internal combination of different blockchain types and the combination of blockchain with other technologies improve the blockchain-based energy trading system to better satisfy the practical requirements of modern power systems. However, there are still some problems to be solved, for example, the lack of regulatory system, environmental challenges and so on. In the future, we will strive for a better optimized structure and establish a comprehensive security assessment model for blockchain-based energy trading system.This research was funded by Beijing Natural Science Foundation (grant number 4182060).Scopu

Trustless communication across distributed ledgers: impossibility and practical solutions

Since the advent of Bitcoin as the first decentralized digital currency in 2008, a plethora of distributed ledgers has been created, differing in design and purpose. Considering the heterogeneous nature of these systems, it is safe to say there shall not be ``one coin to rule them all". However, despite the growing and thriving ecosystem, blockchains continue to operate almost exclusively in complete isolation from one another: by design, blockchain protocols provide no means by which to communicate or exchange data with external systems. To this date, centralized providers hence remain the preferred route to exchange assets and information across blockchains~-- undermining the very nature of decentralized currencies. The contribution of this thesis is threefold. First, we critically evaluate the (im)possibilty, requirements, and challenges of cross-chain communication by contributing the first systematization of this field. We formalize the problem of Cross-Chain Communication (CCC) and show it is impossible without a trusted third party by relating CCC to the Fair Exchange problem. With this impossibility result in mind, we develop a framework to design new and evaluate existing CCC protocols, focusing on the inherent trust assumptions thereof, and derive a classification covering the field of cross-chain communication to date. We then present XCLAIM, the first generic framework for transferring assets and information across permissionless distributed ledgers without relying on a centralized third party. XCLAIM leverages so-called cryptocurrency-backed assets, blockchain-based assets one-to-one backed by other cryptocurrencies, such as Bitcoin-backed tokens on Ethereum. Through the secure issuance, transfer, and redemption of these assets, users can perform cross-chain exchanges in a financially trustless and non-interactive manner, overcoming the limitations of existing solutions. To ensure the security of user funds, XCLAIM relies on collateralization of intermediaries and a proof-or-punishment approach, enforced via smart contracts equipped with cross-chain light clients, so-called chain relays. XCLAIM has been adopted in practice, among others by the Polkadot blockchain, as a bridge to Bitcoin and other cryptocurrencies. Finally, we contribute to advancing the state of the art in cross-chain light clients. We develop TxChain, a novel mechanism to significantly reduce storage and bandwidth costs of modern blockchain light clients using contingent transaction aggregation, and apply our scheme to Bitcoin and Ethereum individually, as well as in the cross-chain setting.Open Acces

Integration of Blockchain and Auction Models: A Survey, Some Applications, and Challenges

In recent years, blockchain has gained widespread attention as an emerging technology for decentralization, transparency, and immutability in advancing online activities over public networks. As an essential market process, auctions have been well studied and applied in many business fields due to their efficiency and contributions to fair trade. Complementary features between blockchain and auction models trigger a great potential for research and innovation. On the one hand, the decentralized nature of blockchain can provide a trustworthy, secure, and cost-effective mechanism to manage the auction process; on the other hand, auction models can be utilized to design incentive and consensus protocols in blockchain architectures. These opportunities have attracted enormous research and innovation activities in both academia and industry; however, there is a lack of an in-depth review of existing solutions and achievements. In this paper, we conduct a comprehensive state-of-the-art survey of these two research topics. We review the existing solutions for integrating blockchain and auction models, with some application-oriented taxonomies generated. Additionally, we highlight some open research challenges and future directions towards integrated blockchain-auction models

Blockchain-based Provenance Solution for Handcrafted Jewellery

Käsitsi tehtud ehete valmistamiseks kasutatakse tootmismasinate asemel inimeste kätetööd. Kui masinate poolt tehtud ehted on samasugused, odavad ja kergesti kättesaadavad, siis käsitsi valmistatud ehted on ainulaadsed ja küllaltki kallid. Seda eriti siis, kui tegemist on tuntud käsitöölise või disaineriga. Käesolev tehnoloogiaajastu on tõstnud tarbijate teadlikkust ning inimesed on valmis rohkem maksma tõestatud päritoluga toodete eest. Samuti soovivad tootjad oma töö eest saada tunnustatud ja omada selle õigusi. Praegused lahendused on pärituolu osas poolikud ning see võimaldab tarneahelal olla läbipaistmatu ning seetõttu kõrvale hiilida läbipaistvusest ning jälgitavusest. Seetõttu on hüppeliselt kasvanud võltstoodangu arv, mis toob kaasa majandusliku ja keskkondliku kahju, terviseriskid, valdkonna halva maine ning rikutud usalduse. Käesolev dissertatsioon vaatleb ja selgitab plokiahela tehnoloogial põhinevaid lahendusi ja võimalusi taustakontrolli tegemiseks ning teostab Ethereumi plokiahelal põhineva lahenduse käsitööehete päritolu kontrolliks. Uurimuse tulemus aitab kaasa taustakontrollimehhanismide arengule ning aitab seda rakendada ülemaailmse tarneahela läbispaistvamaks muutmisel.Handcrafted jewellery involves use of hand labour rather than manufacturing machinery. Unlike manufactured jewellery which is similarly crafted, cheap and easy to find, handcrafted jewellery tend to be uniquely crafted and fairly expensive, especially when it is attributed to a well known artisan or designer. The current information age has birthed a new era of conscious consumers who are willing to pay more for products with proven origins. Likewise, creators desire to be rightfully attributed and acknowledged for their work. However, the partial implementation of provenance by current solutions has encouraged opaque supply chains that hinder transparency and traceability. For this reason, there has been a rapid increase in counterfeit products, unprecedented economic loss, environmental degradation, health risks, increase in defamation cases, and broken trust. In this thesis, we review related provenance solutions using blockchain technology, identify key provenance features and implement a provenance solution for handcrafted jewellery on Ethereum blockchain. The output of this research can be used towards the development of provenance as a subject and its implementation in global supply chains

LabChain: an Interactive Prototype for Synthetic Peer-to-Peer Trade Research in Experimental Energy Economics

Blockchain-based peer-to-peer (P2P) electricity markets received considerable attention in the past years, leading to a rich variety of proposed market designs. Yet, little comparability and consensus exists on optimal market design, also due to a lack of common evaluation and benchmarking infrastructure. This article describes LabChain, an interactive prototype as research infrastructure for conducting experiments in (simulated) P2P electricity markets involving real human actors. The software stack comprises: (i) an (open) data layer for experiment configuration, (ii) a blockchain layer to reliably document bids and transactions, (iii) an experiment coordination layer and (iv) a user interface layer for participant interactions. As evaluation environment for human interactions within a laboratory setting, researchers can investigate patterns based on energy system and market setup and can compare and evaluate designs under real human behavior allowing alignment of intentions and outcomes. This contributes to the evaluation and benchmarking infrastructure discourse

A Survey on Consensus Mechanisms and Mining Strategy Management in Blockchain Networks

© 2013 IEEE. The past decade has witnessed the rapid evolution in blockchain technologies, which has attracted tremendous interests from both the research communities and industries. The blockchain network was originated from the Internet financial sector as a decentralized, immutable ledger system for transactional data ordering. Nowadays, it is envisioned as a powerful backbone/framework for decentralized data processing and data-driven self-organization in flat, open-access networks. In particular, the plausible characteristics of decentralization, immutability, and self-organization are primarily owing to the unique decentralized consensus mechanisms introduced by blockchain networks. This survey is motivated by the lack of a comprehensive literature review on the development of decentralized consensus mechanisms in blockchain networks. In this paper, we provide a systematic vision of the organization of blockchain networks. By emphasizing the unique characteristics of decentralized consensus in blockchain networks, our in-depth review of the state-of-the-art consensus protocols is focused on both the perspective of distributed consensus system design and the perspective of incentive mechanism design. From a game-theoretic point of view, we also provide a thorough review of the strategy adopted for self-organization by the individual nodes in the blockchain backbone networks. Consequently, we provide a comprehensive survey of the emerging applications of blockchain networks in a broad area of telecommunication. We highlight our special interest in how the consensus mechanisms impact these applications. Finally, we discuss several open issues in the protocol design for blockchain consensus and the related potential research directions

Trustworthy Federated Learning: A Survey

Federated Learning (FL) has emerged as a significant advancement in the field of Artificial Intelligence (AI), enabling collaborative model training across distributed devices while maintaining data privacy. As the importance of FL increases, addressing trustworthiness issues in its various aspects becomes crucial. In this survey, we provide an extensive overview of the current state of Trustworthy FL, exploring existing solutions and well-defined pillars relevant to Trustworthy . Despite the growth in literature on trustworthy centralized Machine Learning (ML)/Deep Learning (DL), further efforts are necessary to identify trustworthiness pillars and evaluation metrics specific to FL models, as well as to develop solutions for computing trustworthiness levels. We propose a taxonomy that encompasses three main pillars: Interpretability, Fairness, and Security & Privacy. Each pillar represents a dimension of trust, further broken down into different notions. Our survey covers trustworthiness challenges at every level in FL settings. We present a comprehensive architecture of Trustworthy FL, addressing the fundamental principles underlying the concept, and offer an in-depth analysis of trust assessment mechanisms. In conclusion, we identify key research challenges related to every aspect of Trustworthy FL and suggest future research directions. This comprehensive survey serves as a valuable resource for researchers and practitioners working on the development and implementation of Trustworthy FL systems, contributing to a more secure and reliable AI landscape.Comment: 45 Pages, 8 Figures, 9 Table

SoK: Communication Across Distributed Ledgers

Since the inception of Bitcoin, a plethora of distributed ledgers differing in design and purpose has been created. While by design, blockchains provide no means to securely communicate with external systems, numerous attempts towards trustless cross-chain communication have been proposed over the years. Today, cross-chain communication (CCC) plays a fundamental role in cryptocurrency exchanges, scalability efforts via sharding, extension of existing systems through sidechains, and bootstrapping of new blockchains. Unfortunately, existing proposals are designed ad-hoc for specific use-cases, making it hard to gain confidence in their correctness and composability. We provide the first systematic exposition of cross-chain communication protocols. We formalize the underlying research problem and show that CCC is impossible without a trusted third party, contrary to common beliefs in the blockchain community. With this result in mind, we develop a framework to design new and evaluate existing CCC protocols, focusing on the inherent trust assumptions thereof, and derive a classification covering the field of cross-chain communication to date. We conclude by discussing open challenges for CCC research and the implications of interoperability on the security and privacy of blockchains

Token Economy – Towards Building a Sustainable Blockchain Token Ecosystem Framework

Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Information Systems and Technologies ManagementIn the context of the internet’s historical trajectory, blockchain technology represents a significant paradigm shift from Web 2.0 to Web 3.0. Web 2.0, the current world of the interactive and social web, is an internet siloed by centralized organizations that provide services in exchange for personal data. Web 3.0, on the other hand, is based on cryptographic blockchain technology and enables an economic institutional infrastructure that is natively available on the web, hands ownership back to the creators and users and operates without an intermediary. Blockchain tokens enable digital scarcity and a novel internet-native value transfer mechanism. Tokens can have a magnitude of different use cases ranging from serving as unit of account (currency), promoting usage incentive, as tool for governance, representation of ownership or as a funding instrument. The research field of token creation is still in its very infant stage and a lot of blockchain project launches still happen without proper structure and long term strategy – leading to suboptimal and short lasting results. Based on the Design Science Research methodology, this dissertation attempts to design a holistic conceptual framework that can serve as a base for a decision aid for organizations when creating a blockchain token ecosystem. This artifact will finally be evaluated by domain experts to ensure proper correctness