Distributed file storage aims to support credible access to data on distributed nodes. There are some application scenarios, for example, data centers, peer-to-peer (P2P) storage systems, and storage in wireless networks. Nevertheless, among these applications, data blocks are inevitably replaced and inaccessible when there exists nodes failure. As a result, data integrity and credibility is absent. To overcome such a challenge, blockchain is explored to protect the distributed data. Through analysis and evaluation, we demonstrate that blockchain advocates data integrity and credibility for distributed file storage, as well as the application of blockchain technology for distributed file storage.
The transaction efficiency of blockchains has been a painful point haunting researchers all the time. The metrics of Transaction per Second (TPS) present a low value, especially as the number of network nodes increases. In order to improve the blockchain's TPS, numerous articles explored the solutions from multiple aspects, such as: using a new block system based on the Directed Acyclic Graph (DAG), adjusting the block structure, optimizing the consensus algorithm or adopting a sharding protocol. The sharding protocols play an extremely important role among these schemes, while the existing ones suffer from secure risks due to their static sharding. In this paper, we proposed a dynamic sharding protocol for consortium blockchains, employing random values to randomly partition the network. Our protocol aims for improving the throughput of the blockchain system as well as ensuring its security. The OMNET++ simulation results showed that, in the case of a large-scale consortium blockchain network of 400 nodes which is divided into 16 shards, the performance of our scheme is able to attain up to 50 times promotion, compared to the system without sharding.
Blockchain is starting to be deployed in industries by enabling Internet of Things (IoT) for autonomous deviceto-device transactions through distributed blockchain-based immutable ledger technology. However, traditional block-based blockchain techniques, such as Bitcoin and Ethereum, are not suitable for IoT transactions due to its low throughput, high computation overhead, and costly transaction fee. To satisfy the requirements of IoT, DAG-based approaches, aiming to provide cheap blockchain services with low latency and high throughput, are emerging. In this paper, we present a set of comprehensive experimental studies on IOTA, a representative DAG-based blockchain, and aim to exhibit its unique characteristics mainly from two aspects: performance and security. We have developed a series of benchmark tools and judiciously selected typical configurations to perform experimental examinations with a real private IOTA network. Our studies reveal several interesting findings: 1) The throughput of IOTA is higher than the traditional block-based blockchain, but far less than the reported thousands TPS in its whitepaper, even with scaling-up configurations; 2) The database query heavily impacts the performance of IOTA, even more than its PoW (Proof of Work) process. We make our benchmark tools in public and expect our works can inspire system architects, application designers, and practitioners with new optimization directions and potential application cases for further exploration.
Chaoxia Qin, Bing Guo, Yan Shen, Tao Li · 6 authors
Blockchain technology has emerged as a novel distributed ledger technology, facilitating data sharing and system management securely and efficiently without interventions from a central authority. However, blockchain technology alone is not suitable for enterprise-class applications, mainly due to the limitations in capacity expansion and verification speed of blockchain systems. This paper proposes a secure and effective construction scheme for blockchain networks to improve performance and address the effective management concerns of blockchain data based on transaction categories. We designed a network link protocol to construct a directed acyclic graph (DAG) blockchain network and used a sharding protocol to divide the DAG blockchain into multiple category shards to process transactions in parallel. We then extensively evaluated our proposed design on local clusters. The experimental results show that our link and shard protocols achieved high throughput and the category-based sharded DAG blockchain demonstrated high scalability.
Since Satoshi Nakamoto launched bitcoin in 2009, there have been many improvements in bitcoin addresses that are required to fulfill newer requirements. These improvements have made the learning curve steeper for a regular user. Many readers do not know the real motivation why certain features are implemented or otherwise. In this paper, the evolution of bitcoin addresses is clearly described so that users can better understand the progress made in bitcoin. This paper also explains the motivation for some features' motivation and why these features were implemented in a certain way.
Services computing can offer a high-level abstraction to support diverse applications via encapsulating various computing infrastructures. Though services computing has greatly boosted the productivity of developers, it is faced with three main challenges: privacy and security risks, information silo, and pricing mechanisms and incentives. The recent advances of blockchain bring opportunities to address the challenges of services computing due to its build-in encryption as well as digital signature schemes, decentralization feature, and intrinsic incentive mechanisms. In this paper, we present a survey to investigate the integration of blockchain with services computing. The integration of blockchain with services computing mainly exhibits merits in two aspects: i) blockchain can potentially address key challenges of services computing and ii) services computing can also promote blockchain development. In particular, we categorize the current literature of services computing based on blockchain into five types: services creation, services discovery, services recommendation, services composition, and services arbitration. Moreover, we generalize Blockchain as a Service (BaaS) architecture and summarize the representative BaaS platforms. In addition, we also outline open issues of blockchain-based services computing and BaaS.
Jonas Theis, Luigi Vigneri, Lin Wang, Animesh Trivedi
Permissionless distributed ledger technologies (DLTs) utilize an underlying peer-to-peer network to disseminate transactions. These types of networks have been shown to be highly heterogeneous. However, current DLTs fail to consider this heterogeneity which can render low-end nodes to be unable to participate in consensus.
Many recent research works have proposed distributed ledger technology (DLT) that employs Byzantine fault-tolerant (BFT) consensus protocols as the underlying core primitive to create a total order among all transactions. Compared to many Proof-of-Work (PoW) blockchains, this design typically benefits from increased performance, energy efficiency and proven liveness and safety characteristics. While BFT protocols have the potential to create highly resilient infrastructures, some questions yet remain to be answered. This paper sketches our current and future research on how DLTs can benefit from making the underlying BFT protocol adaptive towards the system's environment (e.g., geographic decentralization or system scale) and resilient against attacks of malicious replicas that are targeted at degrading the overall system performance.
Michael G. Xevgenis, Dimitrios G. Kogias, Panagiotis Karkazis, Helen C. Leligou · 5 authors
With the advent of Software Defined Networking (SDN) and Network Function Virtualization (NFV) technologies, the networking infrastructures are becoming increasingly agile in their attempts to offer the quality of services needed by the users, maximizing the efficiency of infrastructure utilization. This in essence mandates the statistical multiplexing of demands across the infrastructures of different Network Providers (NPs), which would allow them to cope with the increasing demand, upgrading their infrastructures at a slower pace. However, to enjoy the benefits of statistical multiplexing, a trusted authority to govern it would be required. At the same time, blockchain technology aspires to offer a solid advantage in such untrusted environments, enabling the development of decentralized solutions that ensure the integrity and immutability of the information stored in the digital ledger. To this end, in this paper, we propose a blockchain-based solution that allows NPs to trade their (processing and networking) resources. We implemented the solution in a test-bed deployed on the cloud and we present the gathered performance results, showing that a blockchain-based solution is feasible and appropriate. We also discuss further improvements and challenges.
The Internet has changed business, education, healthcare, banking etc. and it is the main part of technological evolution. Internet provides us a connecting world to perform our day to day life activities easily. Internet is designed in such a way that it can uniquely identify machine, not a person, on the network hence there is need to design a system that can perform entity identification on the Internet. Currently on Internet, service providers provide identity of a user with user name and password and store this information on a centralized server. These servers become honey pot for hackers to steal user's personal identity information and service provider can utilize user identity information using data mining, artificial intelligence for economic benefits. Aim of Self sovereign identity system is to provide decentralized, user centric identity system which is controlled by identity owner that can be developed along with distributed ledger technology i.e. blockchain. In this paper, we intend to make an exhaustive study on different blockchain based self sovereign identity implementations (such as Sovrin, Uport, EverID, LifeID, Sora, SelfKey) along with its architectural components and discuss about use case of self sovereign identity.
We make a case for using the emerging blockchain technology for spectrum sharing in Citizen's Broadband Radio Service (CBRS). We show that blockchain can dynamically allocate channels in a transparent and fair manner by achieving distributed channel de-confliction. Furthermore, blockchain helps automate communication between the Spectrum Access Systems (SASs) belonging to competing, non-trusting organizations by providing consensus, while at the same time preserving confidentiality of sensitive information. We implement our CBRS blockchain architecture using the Hyperledger Fabric platform. In order to support high channel request rates, we also develop a novel feature that adaptively pre-processes channel allocation requests at the SAS before sending those to the blockchain network. We evaluate our blockchain solution under different settings and show that it meets the FCC latency requirements. We also analyze the scalability of our system and show that the latency and throughput guarantees can be maintained in scenarios involving multiple organizations.
Rongli Gai, Xiaoyan Du, Shuya Ma, Na Chen · 5 authors
Abstract Blockchain is an emerging distributed database technology. It has the characteristics of decentralization, non-tampering, traceability and final consistency. Blockchain can solve data management problems in untrusted environments. Based on the research and analysis of the blockchain system, this article expounds the application of the blockchain system in the distributed database environment. First, this article introduces the concept of the blockchain system and the classification of the blockchain system from multiple aspects. Then it introduces the data storage technology and data encryption technology adopted by the blockchain system in detail. Finally, the application prospects of the blockchain system in today’s society are introduced.
Antonyo Douglas, R. H. Holloway, Jonathan Lohr, Elijah Morgan · 5 authors
Today’s networks are seeing a large influx of Internet connected devices that reside primarily on the edge of the network. Many of these devices, such as Internet of Things (IoT) devices, are resource constrained both by storage capacity and power requirements that limit a device’s Internet availability. Several interesting architectures have been proposed to address security, device management, configuration, and multi-party interaction concerns using blockchain technology. These architectures require a trusted intermediary to interact with the blockchain on behalf of the edge device. This introduces a single point of failure in trust and security. This paper proposes a novel adaptation of blockchain technology to enable these edge devices to interact and participate with a blockchain without requiring a trusted intermediary. The proposed architecture provides a flexible and extensible framework that enables multi party interactions to take place at the edge of the network. The efficacy of the proposed design is demonstrated through theoretical analysis and by an application to a network of resource constrained IoT devices.
Gustavo F. Camilo, Gabriel Antonio F. Rebello, Lucas Airam C. de Souza, Otto Carlos M. B. Duarte
The trust centralization in current data sharing systems restricts the owner's control over their data. Furthermore, the owner's intervention to authorize his/hers data access for each request makes frequent access to popular data tiresome. In this paper, we propose AutAvailChain, an architecture based on software defined networking (SDN) and blockchain to provide secure, automatic, and distributed sharing of IoT data. We develop a prototype using the Hyperledger Fabric platform to implement the blockchain and a smart contract. The results show a quick, secure, and excellent performance of dozens of transactions per second.
Dec 1, 2020·2020 IEEE Intl Conf on Parallel & Distributed Processing with Applications, Big Data & Cloud Computing, Sustainable Computing & Communications, Social Computing & Networking (ISPA/BDCloud/SocialCom/SustainCom)
Confronted with the explosive growth of data in various cyber systems, decentralized storage has gained popularity thanks to its ubiquitousness, since the devices can share their idle storage space for higher scalability. However, current decentralized storage networks suffer the failure risk due to the insufficient trust among nodes, in addition to the lack of a reliable resource allocation mechanism. In this paper, we present a novel trusted shared storage network, namely TSSN, to achieve efficacious decentralized storage with trust. Designed under a shared storage framework, TSSN introduces blockchain via an on/off-chain collaborative protocol, which realizes the decentralized trust with promising efficiency. In the primary novelty of TSSN, we design an allocation mechanism based on trading and multi-attribute bilateral matching to maintain the stability and fluidity of resources. To verify the practical effectiveness of our solution, we implement a TSSN prototype on our testbed based on IPFS and Ethereum. The experimental results demonstrate the performance of TSSN within on-chain storage overhead, throughput, and latency.
Junzhi Yan, Xiaoyong Hang, Bo Yang, Li Su · 5 authors
Some issues such as CRL/OCSP (Certificate Revocation List / Online Certificate Status Protocol) unavailable, previsioned trust anchor unavailable, high communication load arise when PKI (Public Key Infrastructure) is leveraged into mobile networks. A blockchain based PKI framework in mobile network is proposed to solve these issues. The system is constituted by submission nodes, validator nodes, inquiry nodes. Scenarios and application cases are provided, and it shows the system can be widely used in mobile networks. The blockchain based PKI system is analyzed and compared to traditional solutions. It shows the trustworthy of SSL (Security Socket Layer) certificates and device certificates are the same as those in traditional PKI system. The storage requirement and certificate capacity of blockchain based PKI system is analyzed. Since certificates have expiry dates, the optimization method based on the invalid certificates is proposed. The optimization improves the storage efficiency of the blockchain based PKI certificate management system.
Blockchain technology has emerged to provide immense security solutions and create trust between the stakeholders. In a multi-application scenario, fair resource allocation is complex and challenging. Various Resource Allocation Schemes (RAS) have been proposed by the researchers across the globe, but these solutions are not sufficient to handle the security, trust, latency, and bandwidth issues in the network, which introduces vulnerabilities in the system. Motivated from the aforementioned issues, this paper proposes Block-RAS, a blockchain-based RAS to manage the demand-supply of resources between the users and resource providing companies (RPC) in a secured and trusted environment. Block-RAS provides a highly reliable, low-latency, and bandwidth optimum communication between users and RPC with embedded 6G network infrastructure. In Block-RAS, the security, trust, and transparency are achieved using ethereum blockchain, whereas the cost-effective and optimum bandwidth utilization is achieved using the Interplanetary File System (IPFS). Finally, the performance evaluation of Block-RAS is done by a comparative analysis of the proposed approach with traditional approaches that are dependent on centralized 5G based schemes where the Block-RAS outperforms in terms of delay, packet-loss, blockchain block-size, scalability, and network bandwidth utilization.
Evaluating Blockchain performance is not an easy task. It is difficult to compare different systems, since the evaluation is often incomprehensible and conducted in different environments with distinct workloads. Only a handful of prior tools were proposed, e.g., BLOCKBENCH and HFBench. Unfortunately, these tools have several limitations. We first identify these limitations. Second, motivated by our observations, we then present a benchmarking tool, Boston Blockchain Benchmarking (BBB). BBB is configurable, extensible, and easy-touse. In particular, BBB can be used to test Blockchain from a networking perspective, a feature that we have not observed in prior tools. Similar to BLOCKBENCH, we focus on the private Blockchain. Concretely, we integrate our tool with Mininet, and provide a simple mechanism to test how network properties (e.g., latency, bandwidth, package loss rate) affect the performance of the chosen Blockchain. We present our preliminary result of evaluating Ethereum. We stress that the architecture of BBB is general, and could be extended to other Blockchain systems. BBB is extremely lightweight and can be used on your laptop to test a small network. Such a feature allows quick evaluation of the Blockchain and speeds up innovation and development.
Abstract Bitcoin has always been used to store arbitrary data, particularly since Bitcoin Core developers added a dedicated method for data storage in 2014: the OP Return operator. This paper provides an in-depth analysis of all OP Return transactions published on Bitcoin between September 14, 2018, and December 31, 2019. The 32.4 million OP Return transactions (22% of all Bitcoin transactions) published during this period added 10 GB to the blockchain’s size. Almost all OP Return transactions can be attributed to one of 37 blockchain services. The two dominant services are Veriblock (58% of OP Return transactions) and Omni/Tether (40%). Veriblock transactions pay only 14% of the average transaction fee, partly because most of them are submitted during times when overall activity on Bitcoin is low. Omni transactions, on the other hand, pay more than twice the average transaction fee and therefore compete with regular Bitcoin transactions for inclusion in new blocks.
Bruno Machado Agostinho, Fellipe Bratti Pasini, Fernanda Oliveira Gomes, Alex Sandro Roschildt Pinto · 5 authors
The interest in blockchain technologies has been growing in the last years. Decentralization, scalability, and data integrity are characteristics that can solve problems in different application fields. However, some issues need to be addressed, aiming to facilitate using these systems. Every day the number of users increases, and the possibility of using multiple cryptocurrencies, with several wallets in each one, also brought an issue: How to manage all these addresses? This work proposes a novel architecture, named Wallet Domain Name System (WDNS), to handle several wallets and contracts in different blockchains. Using the Ethereum network to develop a DNS approach, the WDNS uses smart contracts to store and resolve domains and enable multiple subdomains that are managed by the users. Our work provides an open and free data architecture where any person and system can connect and consume. The initial tests showed an average transaction time of almost 15 seconds and a price of 3.30 USD plus 0.0012 USD per character for the domain requests. Also, the tests showed a fixed cost of 0.71 USD plus 1 USD per each synchronized instruction. Comparing the proposed domain price and the average renewal prices for internet domains makes it possible to ensure our proposal's feasibility.
In this paper, we evaluate and analyze the performance of a local electricity market for energy trading that we implemented on the Ethereum platform. The energy trading is based on a double auction with multiple sellers and multiple buyers, and the matched price and volume are determined by a trade reduction mechanism. We benchmark the performance of Ethereum using a systematic blockchain performance evaluation method, and based on this, we propose and analyze an efficient market operation method. In particular, we relate the limits on the scalability and real-time performance of the market to the throughput and latency of the Ethereum platform. We also identify the minimum resources necessary to operate an Ethereum client.
The storage structure on the data block of the current blockchain systems is still a linked list. This traditional structure is one-way and is not efficient for query operation. In view of this, we proposed a novel searching structure based on a height balanced Binary Search Tree (BST). The data structure we proposed not only retains the characteristics of the traditional ledgers but also adds the function of quick query. Through the new data structure, we can quickly find the starting position of the search and start searching for all transaction records within a specified range of time from this position. We also made an analysis and comparisons in the final.
Florian Adamsky, Daniel Kaiser, Michael Steglich, Thomas Engel
Distributed Hash Table (DHT) protocols, such as Kademlia, provide a decentralized key-value lookup which is nowadays integrated into a wide variety of applications, such as Ethereum, InterPlanetary File System (IPFS), and BitTorrent. However, many security issues in DHT protocols have not been solved yet. DHT networks are typically evaluated using mathematical models or simulations, often abstracting away from artefacts that can be relevant for security and/or performance. Experiments capturing these artefacts are typically run with too few nodes.