Existing NFTs confront restrictions of one-time incentive and product isolation. Creators cannot obtain benefits once having sold their NFT products due to the lack of relationships across different NFTs, which results in controversial profit sharing. This paper proposes a referable NFT solution to extend the incentive sustainability of NFTs. We construct the referable NFT (rNFT) network to increase exposure and enhance the referring relationship of inclusive items. We introduce the DAG topology to generate directed edges between each pair of NFTs with corresponding weights and labels for advanced usage. We accordingly implement and propose the scheme under Ethereum Improvement Proposal (EIP) standards, indexed in EIP-5521. Further, we provide the mathematical formation to analyze the utility for each rNFT participant. The discussion gives general guidance among multi-dimensional parameters. The solution, as a result, shape the recognition of potential values hidden in isolated NFTs and raise the interest of communities toward the discovery of NFT derivatives. To our knowledge, this is the first study to build a referable NFT network, explicitly showing the virtual connections among NFTs.
Blockchain is the technology to secure transaction by connected ledgers. Non Fungible Token (NFT) transactions are getting popular daily from 2021 and it generates new economy world. The transactions of NFTs are stored in the blockchain but the contents of NFTs are not stored if the contents are so big amount of volume, because of higher transaction gas fee. We propose long term storage node system architecture named Sustainable Generation Manager (SGM) which is using hash based file system on storage node on blockchain to maintain these contents of data of NFTs. This paper shows the architecture, parameters and implementation of SGM on our original voting blockchain.
Marco Marcozzi, Leonardo Mostarda, Diletta Cacciagrano
As micro grids and blockchain gained the interest and attention of both academia and the industry, the interaction between the two technologies seems inevitable. However, there are challenges to overcome in order to actually realize the integration between micro grids and blockchains. In this article, we review the solutions proposed to enhance micro grids with blockchains. We discuss the scalability challenges and the opportunities derived from the off-chaining computing techniques. In this context, we draft a design to implement a micro grid-based peer-to-peer local energy market, powered by an off-chain computing protocol called DIVERSITY. DIVERSITY aims to shift the computational burden from a main blockchain to an intermediate layer of nodes, aggregating data and executing smart contracts off-chain. We simulate different data logging approaches, and it is found that DIVERSITY allows an actual saving on fees and power consumption derived from using a public blockchain platform, such as Ethereum, in order to assure a truly decentralized renewable energy distribution at a lower cost.
Sina Kamali, Shayan Shabihi, Fakharian, Mohammad Taha, Alireza Arbabi · 7 authors
The consensus protocol is the core of a blockchain system which guarantees its secure and stable operation. Proof of Activity (PoA) is a consensus protocol that tries to address some of the issues pertinent to the most widely used protocols, such as Proof of Stake (PoS) and Proof of Work (PoW). However, it still needs to solve the issues regarding high energy consumption, significant resources required, high mining latency, and the need for private blockchains. In this paper, we propose Redefined Proof of Activity (RPoA), a new consensus protocol that builds on top of some of the best features of the existing protocols, such as PoW, PoS, and PoA, and values active service provided by users on the network. Our approach tries to address the issues above and falls in the service-based protocols category that gives mining credit to users as they serve on the network.
Over time, distribution systems have begun to include increased distributed energy resources (DERs) due to the advancement of auxiliary power electronics, information and communication technologies (ICT), and cost reductions. Electric vehicles (EVs) will undoubtedly join the energy community alongside DERs, and energy transfers from vehicles to grids and vice versa will become more extensive in the future. Virtual power plants (VPPs) will also play a key role in integrating these systems and participating in wholesale markets. Energy trading on a peer-to-peer (P2P) basis is a promising business model for transactive energy that aids in balancing local supply and demand. Moreover, a market scheme between VPPs can help DER owners make more profit while reducing renewable energy waste. For this purpose, an inter-VPP P2P trading scheme is proposed. The scheme utilizes cutting-edge technologies of the Avalanche blockchain platform, developed from scratch with decentralized finance (DeFi), decentralized applications (DApps), and Web3 workflows in mind. Avalanche is more scalable and has faster transaction finality than its layer-1 predecessors. It provides interoperability abilities among other common blockchain networks, facilitating inter-VPP P2P trading between different blockchain-based VPPs. The merits of DeFi contribute significantly to the workflow in this type of energy trading scenario, as the price mechanism can be determined using open market-like instruments. A detailed case study was used to examine the effectiveness of the proposed scheme and flow, and important conclusions were drawn.
Zhenni Li, Wensheng Su, Minrui Xu, Rong Yu · 6 authors
Dynamic off-chain routing in payment channel network (PCN)-based Internet of Things (IoT) is attracting increasing research attention. However, there are two major issues in dynamic routing in PCN-based IoT with resource-limited devices. The first issue is how to achieve high long-term transaction efficiency in PCN with dynamic channel capacities. The second issue is how to achieve a lightweight routing algorithm deployed on IoT devices while achieving high transaction efficiency, i.e., successful payment amount and success ratio. Therefore, in this paper, we propose a compact deep reinforcement learning (DRL) algorithm to learn the joint dynamic and lightweight routing policy for maximizing long-term transaction efficiency. To obtain optimal performance in dynamic routing problems for off-chain systems, a proximal policy optimization algorithm is employed to create an actor–critic learning structure for training the teacher DRL model. To obtain a compact and efficient student DRL model, an adaptive pruning technique is utilized for pruning unnecessary parameters of networks in the teacher model adaptively without affecting its learning ability. Furthermore, knowledge distillation is leveraged to improve the performance of the student network. Thus, a compact and efficient student DRL model can be developed and implemented to maximize the long-term transaction efficiency in off-chain systems on resource-limited IoT devices. The simulation results demonstrate that the proposed DRL algorithm outperforms the other baseline algorithms in PCN transaction efficiency while requiring only 10% of the computation and storage resources compared with that of the original teacher model.
Once deployed, a decentralized blockchain system ensures that it will operate faithfully so that no one can interfere with or manipulate its predefined regulations, such as block size and block creation interval investigated in this paper. However, fixed regulations prevent that system from adapting to the change of the environment, such as increasing the underlying network capacity, and result in sub-optimal performance. For example, Bitcoin remains at 7 TPS (transactions per second), even operating over the current Internet. In this paper, we propose a new paradigm for defining the behavior of a consensus system, named as Meta-Regulation, which allows autonomous evolution of the system behavior. A meta-regulation adjusts the actual behavior of a consensus system in response to the changing capacity of the underlying infrastructure and the community of participants. We demonstrate the effectiveness of the proposed meta-regulation by achieving significantly improved throughput and latency for Bitcoin, adapted to the current capacity of the Internet. Our experimental results show that Meta-Regulation can achieve at least$7\times $performance improvement over Bitcoin network deployed in 2009, resulting in 49.7 TPS or 68% reduction confirmation latency by fully utilizing the bandwidth and the computing power of average network nodes.
Broadcasting plays a vital role in the consensus mechanisms of blockchain systems, since the consensus of each block must wait until the previous block is received by (nearly) all the nodes in the blockchain systems. Therefore, optimizing the performance of broadcasting can significantly improve the performance of the blockchain system. However, compared with other traditional P2P applications such as file downloading or video delivery, the broadcasting in blockchain has two new requirements, namely low redundancy and low propagation latency, which all the existing mechanisms (e.g. flooding, structural DHT etc.) can not meet well. In this paper, we propose Swift, a new broadcasting mechanism for blockchain systems. It optimizes the P2P topology construction and broadcast algorithm in the structured network based on unsupervised learning and greedy algorithm, effectively reducing the propagation latency of the blockchain P2P network while avoiding the waste of redundant bandwidth. We implemented a prototype of Swift and evaluated its performance on a testbed network that consists of 1000 blockchain nodes. The experimental findings show that Swift can reduce propagation latency by 19.8% with similar bandwidth consumption, generating an 18% increase in the throughput performance of the blockchain. Finally, with the increase in connections, Swift can simultaneously achieve low latency and maintain a relatively stable redundant bandwidth waste, instead of linearly increasing in flooding.
Sahilpreet Singh Sidhu, Minh Nam Hai Nguyen, Chikamnaele Ngene, Sara Rouhani
Despite advances in developing various blockchain platforms and services, disparate blockchain networks do not support direct communications, causing fragmentation and data and asset in silos. Blockchain interoperability is a solution that allows communication between different blockchain platforms to exchange data and assets. This study investigates a blockchain interoperability solution based on publish-subscribe architecture to share data between various blockchain platforms. We extend the solution by providing decentralized identifiers and verifiable credentials to the users sharing and accessing data through inte-gration with Hyperledger Indy, Aries, and Ursa stack projects, which are blockchain services offering decentralized identity. We also designed a testbed comprising multiple permissioned blockchain platforms integrated with decentralized identity ser-vices to evaluate the proposed system's security and integrity
The purpose of this paper is to present a prototype of a platform for data exchange that integrates blockchain and distributed file system technologies. The development phases are defined, an architecture and topology design is suggested, and the main functionalities of the prototype are implemented. Also presented are experiments and results on prototype’s performance and resource usage evaluation. The presented prototype’s functionalities enable upload/download files operations, a monetization protocol, digital rights management for some file formats, testing the performance with different file sizes, testing the decentralized operation mode, performance and resource usage evaluation and activity log reporting. Presented are results of 800 test experiments for the blockchain and distributed file system networks performance, the prototype functionality verification and the estimation of resource usage.
The current distributed storage solutions are still concentrated in third-party storage service providers, and the stored data are concentrated in a few cloud servers, which inevitably brings the risk of data loss, leakage, and tampering, so it is imperative to study a distributed storage and decentralized storage system. How to maintain the consistency of data in a distributed environment has become a problem in building decentralized applications, until the emergence of blockchain technology, whose decentralized, non-tamperable, and traceable features can solve this problem well. In this paper, we design a decentralized storage system combining Hyperledger Fabric and Inter Planetary File System (IPFS). In addition, from the perspective of security and availability of the decentralized storage system, we study the partitioning and the k-r allocation scheme of the stored data, propose the allocation function about the stored files, derive the mathematical formula of file security and availability based on the allocation function, and discuss the optimal parameter setting of the allocation function based on the formula to guarantee the high security and availability of the stored files. The experimental results show that the performance of the k-r allocation policy based on the minimum number nodes (MNN) is better than that of the k-r allocation policy based on the minimum slices number (MSN); however, with the same security and availability guarantees, the MNN policy will have more copies relative to the MSN policy, which is relatively wasteful of space.
The rapid development of the blockchain leads to a blowout of on-chain transactions, contracts, and currencies, which will further accelerate the increase of data. The existing blockchain systems typically support exact transaction queries, which, however, cannot satisfy the QoS requirements with intelligent adjustment in the blockchain systems. To this end, this paper takes the first step to define and address the practically important problem of transaction cardinality estimation for QoS-adjustable intelligent blockchain systems. We first establish a mathematical relationship between the bit string and transaction cardinality. Thus, we can leverage the number of leading 1s of the obtained bit string to estimate the transaction cardinality. We then improve the block header and body with a corresponding search algorithm to access bit strings in blocks. We also propose an estimation protocol with intelligent adjustable QoS to support accuracy-guaranteed and efficiency-optimized estimation. Finally, we design an authentication scheme and guarantee the reliability of our protocol through rigorous theoretical derivation. When achieving the transaction cardinality estimation in blockchain, two technical challenges need to be addressed. (i) To ensure efficient, verifiable, and overhead-saving bit string accessing mechanism in blockchain, we propose the Merkle Cardinality Tree (MCT) and target block filtering mechanism based on Bloom Filter (BF) in off-chain and improve on-chain block header by joining the abstract of MCT and BF. (ii) To improve estimation efficiency while guaranteeing accuracy requirements in hybrid blockchain scheme, we propose a Dynamic One-round Sampling-based cardinality Estimation (DOSE) protocol and integrate BF-DOSE to intelligently accelerate estimation. We build MCT in Ethereum and store the MCT Root in the block header for estimation authentication. Extensive experiments reveal that our BF-DOSE protocol can well satisfy various accuracy and efficiency requirements of QoS-adjustable intelligent blockchain systems, and is one to two orders of magnitude faster compared with benchmark schemes.
Blockchain performance cannot meet the requirement nowadays. One of the crucial ways to improve performance is sharding. However, most blockchain sharding research focuses on the public blockchain. As for consortium blockchain, previous studies cannot support high cross-shard efficiency, multiple-shard contract calling, strict transaction atomicity, and shard availability, which are essential requirements but also challenges in consortium blockchain systems. Facing these challenges, we propose Meepo, a systematic study on sharded consortium blockchain. Meepo enhances cross-shard efficiency via the cross-epoch and cross-call. Moreover, a partial cross-call merging strategy is designed to handle the multi-state dependency in contract calls, achieving flexible multiple-shard contract calling. Meepo employs a replay-epoch to ensure strict transaction atomicity, and it also uses a backup algorithm called shadow shard based recovery to improve the shard robustness. On a test-bed of 128 AliCloud servers, setting 32 shards and 4 consortium members, Meepo-OpenEtheruem can achieve more than 140,000 cross-shard TPS under the workload of 100,000,000 asset transactions. It also shows more than 50,000 TPS under the transactions of real-world shopping behaviors.
Sharing data across various Internet of Things (IoT) devices has been a common challenge due to efficiency, security, and stability issues. Blockchain, with security features, is considered to be a potential solution for data sharing in IoT settings. However, traditional blockchain-based solutions cannot satisfy the efficiency requirement of high-frequency data sharing among IoT devices. In this paper, we propose an efficient IoT data sharing approach by adopting the Payment Channel Network (PCN)-extended blockchain. Besides, we develop a homomorphic hashing-based transaction segmentation scheme to solve the issue of low transaction success ratio caused by channel deposit restrictions in PCN. In addition, a Multi-point Relay (MPR)-based multi-path routing scheme has been developed to ensure high-frequency transaction forwarding. The communication overhead of maintaining the routing table is reduced by our proposed Multi-point Relay Selection algorithm, and multiple alternate paths generated by Multiple Routing Path algorithm can improve the transaction success rate. Experiment evaluations have demonstrated that that our proposed approach outperforms the baseline approaches in terms of the transaction efficiency and success ratio.
Most companies relay on centralized servers, which are considered as a fast and easy to deploy solution for file sharing, but they have many downsides, like security and trust issues, which can be solved using DLT (blockchain) solutions. However, DLT-based solutions have many challenges, such as nodes orchestration, adjusting reliability and double-spending, as well as load balancing. This research proposes a DLT (Distributed Ledger Technology) based model for files storage for companies using p2p networks, which takes into account both data reliability and storage space efficiency. More efficient data storage is achieved through the use of the Erasure coding technique. For load balancing, a set of algorithms that can be implemented in the form of a smart contract were proposed. The described model can become the basis of the IT infrastructure for trusted exchange of documents, technical and scientific information, games distributions, mobile applications, updates of scientific, regulatory and technical databases in b2b and b2c format
Conor Mullaney, Adnan Aijaz, Nathan Sealey, Ben Holden
Peer-to-Peer (P2P) energy trading provides various benefits over conventional wholesale energy markets and makes renewable energy more accessible. This paper proposes a novel multi-layer P2P energy trading system for microgrids based on IOTA 2.0, which is a distributed ledger technology (DLT) primarily designed for Internet-of-Things (IoT) applications. The proposed energy trading system, which is a manifestation of a cyber-physical system (CPS), exploits the benefits brought by IOTA's unique ledger structure as well as the recently introduced IOTA smart contract protocol (ISCP). Further, it implements a uniform double-auction market mechanism and a hierarchical routing structure for interconnected microgrids. Performance evaluation demonstrates key benefits over wholesale markets as well as speed, energy efficiency and cost benefits over conventional blockchain-based P2P energy trading systems.
Bitcoin network is one of the most popular blockchain systems. Mining pools are the main components of the Bitcoin network that invest a large amount of computing power to maximize their expected mining payoffs, which guarantees the security of the Bitcoin network. Although many existing works about mining pools are available, the long-term evolution of mining pools, and their effects on both the Bitcoin system and end-users, remain to be investigated. To fill this gap, we trace over 2.54 hundred thousand blocks from Feb 2016 to Nov 2020 and collect over 12 million unconfirmed transactions from Mar 2018 to Nov 2020. We then conduct a broad range of analyses, including the pool evolution, labeled transactions, and labeled blocks. We make the following observations from our measured data: 1) A few mining pools control most of the peer-to-peer network's computing power. 2) The long-term computing power of top mining pools grows exponentially while itscontinuous-time mining strategydecreases linearly. 3) The computing power of the Bitcoin network converges to the Nash equilibrium. We then propose game-based strategies for mining activity analysis, i.e., the best-response strategies for mining pools when the mining revenue increases or decreases sharply. Moreover, we study the transaction fee dilemma of mining pools and the transaction fee strategies for end-users. Our models and analysis can help to understand and improve the Bitcoin system quantitatively.
P. Abhishek, D. G. Narayan, H Altaf, P. Somashekar
The evolution of blockchain has revolutionized the field of security and decentralization. Blockchain enables secure information storage and transfer because to its strong security features and the trust it offers. The users can have authenticity and trust because of the immutability. The two popular open-source blockchain platforms are Ethereum and Hyperledger Fabric. Ethereum is a public blockchain platform that enables secure peer-to-peer applications like crypto-currency and smart contracts. Ethereum has grown a reputation for dependability as a result of big developers taking an interest in it and contributing over time. Hyperledger is a permissioned blockchain platform used by enterprises to mainly induce the power of blockchain in creating immutable ledgers and keep transactions discrete among business entities. The effectiveness and scalability of both private and public networks must be evaluated and assessed. In this paper, we compare and analyse the performance of the hyperledger and ethereum networks. To further fine-tune the configuration parameters and comprehend the performance variances that occur, we developed real-time simulations and built blockchain networks on the Ubuntu OS. By changing the blockchain parameters, it was possible to measure the time it took to group the transactions into a block, the size of the overall block that comprises the bundled transactions, and the latency to construct the blocks. The findings show that when compared to public blockchain networks, private blockchain networks are more robust in performance, have lower latency, and charge no transaction fees
Bitcoin and blockchain technology allow for value to be transferred in small increments. This property makes Bitcoin suitable for pay-as-you-go data streaming models as an alternative to subscription-based media streaming services. One of the key mechanisms Bitcoin provides to enable such use cases is payment channels. These channels allow two parties to perform value exchanges at high frequency, without settling each individual event on-chain, making them suitable for mediating the purchase of a digital data stream on a packet-by-packet basis. However, some existing designs for Bitcoin payment channels rely on funding transactions to escrow tokens, which increases the operational cost of a data stream and can lead to the funds of peers becoming temporarily stranded in the channel. In this paper, we outline a novel payment channel design that overcomes these challenges. Our construction leverages the inherent malleability of Bitcoin transactions to allow either party to unilaterally terminate the stream at any point, without sacrificing the security of the incremental payments that have occurred up to the termination point.
Sustainable, immutable, and affordable data storage to leading universities, research institutions, enterprises, and Web3 organizations. The next generation of platforms will be built on the decentralized web. Unlocking the benefits of the next economy: True ownership, security, and verifiability of data.
Blockchain has become one of the hottest research areas in recent years. The technology could potentially lead to a new generation of decentralized applications and decentralized autonomous organizations. Unfortunately, there is simply too much misinformation regarding blockchain. Most notably, blockchain has been used as a buzzword synonymous with data immutability and trust. In fact, this is far from the truth. In this article, we provide a concise description of exactly what blockchain technology is, including its design principle, building blocks, core innovations, and benefits. This is followed by an analysis of data immutability. We show that to create an insurmountable barrier against attacks on data immutability, decentralization and system scale are both necessary. Based on this analysis, we further dissect what benefits private and consortium blockchain could actually offer when decentralization is removed. We show that private and consortium blockchain cannot offer data immutability and trust as many works in the literature have claimed or implied. Instead, the centralized version of blockchain technology provides an elegant solution to achieving fault tolerance and atomic contract execution, which could make private and consortium blockchain useful for enterprises that would like to provide high availability to their customers and for their internal operations.