This paper describes a new consensus and governance model for the blockchain, with the objective of protecting the blockchain project against higher-level governance issues by design. As governance issues can lead to human problems, they can impact the proper functioning of the blockchain, leading to loss of cryptocurrency value, hard forks, and even failure of the project. We choose several fail-safe mechanisms and processes used and tested in existing Proof-of-Stake and Proof-of-Work implementations in combination with one another in order to create a framework in line with the philosophy of decentralization of the blockchain and safe against the most common technical and governance pitfalls of the field. Additionally, this composite framework offers ideal circumstances for the creation and success of Decentralized Autonomous Organizations by giving their creators more incentive to start new projects, and more involvement with the governance of the underlying blockchain.
In the present scenario, it is vital for any organization, especially the financial organizations, to understand customers and their financial dealings better. KYC is a process to verify identity and related details of corresponding customers. The current KYC mechanism has a severe concern in financial institutions as it requires separate ledger for the separate financial organizations. Every institution has its KYC process, which sometimes may include third-party, which may cause increased maintenance cost, time and redundancy. There is considerable wastage of costs in the form of opportunity cost, maintenance cost, customer verification cost and many more of around $27 million according to an economic survey. The current KYC process is very time-consuming, and it decreases the user experience. We have proposed an enhanced KYC system using blockchain technology to improve the existing KYC system. An inherent feature of the DLT is used to remove the third-party involvement, and smart contracts are used to build our logic in the mobility of the data. Blockchain technology has various types of cryptographic security which provide a safer place to transact over an unsecured channel. Using the facility of DLT, cryptography and consensus mechanism of blockchain, the proposed model of KYC process can optimize storing, updating, sharing of data and accessing operations along with enhanced security, transparency and privacy. It also enhances customer ownership and improves customer experience. It not only reduces the time duration and document update problem but also saves opportunity cost, aggregation, cost, maintenance cost and many more costs, which can affect the performance of any organization.
This article proposes a self-organizing collaborative computing network with an approach to enhance the expectation of a collaborating node for joining the self-organizing network. The proposed approach relies on Ethereum cryptocurrency and Smart Contract to enhance the expectation of collaborating nodes by monetizing the services provided to the self-organizing network. Furthermore, an escrow based smart contract is formalized in the proposed framework to sustains the monetary trust issue between collaborating nodes. The proposed scheme can enforce an autonomic incentive management mechanism to any type of self-organizing networks such as self-organizing clouds, ad-hoc networks, self-organizing federated cloud networks, self-organizing federated learning networks, and self-organizing D2D networks to name a few. Considering the distributed nature of these self-organizing networks and the Ethereum blockchain network, a distributed agent-based methodology is materialized in the proposed framework. Following this, a proof of concept implementation for the general case of a self-organizing cloud is presented. Lastly, the article provides some insights into possible future directions using the proposed framework.
As the use of online transaction is increasing day by day, the security measure parameter is difficult to manage. In that case, Blockchain enables peer-to-peer transfer of digital assets without any intermediaries in a secure manner with the use of verification and validation operation by different miner nodes of decentralized network. Blockchain technology also supports cryptocurrencies like
bitcoin and ethereum for amount transfer digitally with secure communication.
Abhishekh Patil, Amit Kumar Jha, Mohammed Moin Mulla, D. G. Narayan · 5 authors
Cloud forensics investigates the crime committed over cloud infrastructures like SLA-violations and storage privacy. Cloud storage forensics is the process of recording the history of the creation and operations performed on a cloud data object and investing it. Secure data provenance in the Cloud is crucial for data accountability, forensics, and privacy. Towards this, we present a Cloud-based data provenance framework using Blockchain, which traces data record operations and generates provenance data. Initially, we design a dropbox like application using AWS S3 storage. The application creates a cloud storage application for the students and faculty of the university, thereby making the storage and sharing of work and resources efficient. Later, we design a data provenance mechanism for confidential files of users using Ethereum blockchain. We also evaluate the proposed system using performance parameters like query and transaction latency by varying the load and number of nodes of the blockchain network.
Voltage controls the majority of the processes around us, starting from\nlighting an incandescent lamp to running huge machines in industries.\nTherefore, voltage monitoring becomes essential, which demands efficient\nmeasurement and storage of voltage data. However, there is hardly any system\ntill date that fulfils both the goals of voltage monitoring and voltage data\nstorage. To achieve this goal, we propose the application of the Internet of\nThings along with the server-based framework and Distributed Ledger Technology\nto build systems for smart voltage monitoring. Two models - a centralised model\nand a decentralised model have been presented and analysed thoroughly in this\npaper. The centralised model is built on client-server architecture, whereas\nthe decentralised model is based on a peer-to-peer architecture. Blockchain and\nInterPlanetary File System have been used for the implementation of the\ndecentralised system. Potential improvements to make these systems robust have\nalso been discussed. The methods proposed in this paper for voltage monitoring\nare novel; ensure efficient data storage and can be used for IoT data storage\nof any form.\n
The traceable execution of business processes and choreographies using smart contracts is one prominent application of blockchain technology in Business Process Management (BPM). Existing approaches support a large set of patterns, modeling languages, and blockchain architectures, which cover a wide range of practical scenarios. However, they largely neglect the important aspect of time, a crucial part of process and choreography models manifested in deadlines, delays, and other temporal constraints. We argue that this deficit is due to inherent limitations of smart contracts---in particular the absence of a natural notion of measuring time---on popular blockchain platforms used in research and practice. We introduce a set of time measures available on blockchain platforms to alleviate these issues, and systematically compare their properties. We also give hints as to their suitability for facilitating various temporal constraints commonly found in process models.
Ning Wang, Bo Wang, Taoying Liu, Wei Li · 5 authors
Blockchain is a kind of distributed accounting system with the characteristics of decentralization, openness, transparency, non-tampering and de-trust. Recently, blockchain-based applications appear in various fields such as IoT, supply-chain, etc. A practical requirement of applying the Blockchain technology to the conventional supply-chain system is the trans-action synchronization between databases and the blockchain systems. This paper proposes a middleware that supports non-intrusive, efficient, fault-tolerant transaction data synchronization. The middleware is designed under three principles. The first is to divide the process of transaction synchronization into several independent phases. The second is to convert the representation of database transaction into an optimal form for blockchain, and transactions are packed and written into blockchain in a batch mode. The third is to guarantee the consistency between database and blockchain through failure recovery mechanism. Utilities like pipeline processing and transaction mapping built on this middleware achieve significant performance improvement. The peak TPS of Hyperledger Fabric reaches above 16000, which is more than 32 times of the direct submission method.
With the advent of Bitcoin, the interest of the database community in blockchain systems has steadily grown. Many existing blockchain applications use blockchains as a platform for monetary transactions, however. We deviate from this philosophy and present ResilientDB, which can serve in a suite of non-monetary data-processing blockchain applications. Our ResilientDB uses state-of-the-art technologies and includes a novel visualization that helps in monitoring the state of the blockchain application.
This paper presents a PhD research plan that focuses on solving existing problems in requirements engineering, by means of a novel blockchain-enabled framework. Requirements engineering in general and requirements traceability in particular are characterized by a variety of distributed stakeholders and heterogeneity of tools. These characteristics introduce integration, communication, coordination and trust issues and impede the accurate and trustworthy traceability of requirements. Thereby, this paper proposes blockchain technology for the trustworthy management and traceability of requirements throughout the software development life cycle.
Wei‐Tek Tsai, Rong Wang, Shuai Liu, Enyan Deng · 5 authors
Blockchains or DLT (distributed Ledger Technology) receive significant attention recently. However, most of blockchain systems disclosed technical details in whitepapers only, but these whitepapers usually do not provide sufficient materials for a comprehensive evaluation. They do not provide data and do not compare with other systems. This paper proposes a data-driven model to evaluate blockchains from three dimensions: technical, team competence, and community activities with data automatically collected by crawling. As most of data are collected in an automated manner, evaluation and comparison analysis can be done with other blockchain systems in the database. We have developed this system COMPASS and evaluated more than 200 blockchains with highest market valuation. The results are available at Tiande website since December 2018 with frequent updates. The evaluation scores are calculated by combining objective data analysis with a weighting scheme, providing valuable reference for developers, scientists, and investors. The data show that most about 200 key developers dominate the industry and many systems are similar to each other.
Sharding is a promising blockchain scaling solution. But it currently suffers from high latency and low throughput when it comes to cross-shard transactions, i.e., transactions that require coordination from multiple shards. The root cause of these limitations arise from the use of the classic two-phase commit protocol, which involves locking assets for extended periods of time. This paper presents Rivet, a new paradigm for blockchain sharding that achieves lower latency and higher throughput for cross-shard transactions. Rivet has a single reference shard running consensus, and multiple worker shards maintaining disjoint states and processing a subset of transactions in the system. Rivet obviates the need for consensus within each worker shard, and as a result, tolerates more failures within a shard and lowers communication overhead. We prove the correctness and security of Rivet. We also propose a more realistic framework for evaluating sharded blockchains by creating a benchmark based on real Ethereum transactions. An evaluation of our prototype implementation of Rivet and the baseline two-phase commit, atop 50+ AWS EC2 instances, using our evaluation framework demonstrates the latency and throughput improvements for cross-shard transactions.
A blockchain is a distributed ledger forming a distributed consensus on a history of transactions, and is the underlying technology for the Bitcoin cryptocurrency. Its applications are far beyond the financial sector. The transaction verification process for cryptocurrencies is much slower than traditional digital transaction systems. One approach to scalability or the speed at which transactions are processed is to design a solution that offers faster Proof of Work. In this paper, we propose a method for accelerating the process of Proof of Work based on parallel mining rather than solo mining. The goal is to ensure that no more than two or more miners put the same effort into solving a specific block. The proposed method includes a process for selection of a manager, distribution of work and a reward system. This method has been implemented in a test environment that contains all the characteristics needed to perform Proof of Work for Bitcoin and has been tested, using a variety of case scenarios, by varying the difficulty level and number of validators. Experimental evaluations were performed locally and in a cloud environment, and experimental results demonstrate the feasibility the proposed method.
Martín Garriga, Stefano Dalla Palma, Maxmiliano Arias, Alan De Renzis · 6 authors
Abstract Blockchain is a decentralized transaction and data management solution, the technological leap behind the success of Bitcoin and other cryptocurrencies. As the variety of existing blockchains and distributed ledgers continues to increase, adopters should focus on selecting the solution that best fits their needs and the requirements of their decentralized applications, rather than developing yet another blockchain from scratch. In this article we present a conceptual framework to aid software architects, developers, and decision makers to adopt the right blockchain technology. The framework exposes the interrelation between technological decisions and architectural features, capturing the knowledge from existing academic literature, industrial products, technical forums/blogs, and experts' feedback. We empirically show the applicability of our framework by dissecting the platforms behind Bitcoin and other top 10 cryptocurrencies, aided by a focus group with researchers and industry practitioners. Then, we leverage the framework together with key notions of the architectural tradeoff analysis method to analyze four real‐world blockchain case studies from industry and academia. Results shown that applying our framework leads to a deeper understanding of the architectural tradeoffs, allowing to assess technologies more objectively and select the one that best fit developers' needs, ultimately cutting costs, reducing time‐to‐market and accelerating return on investment.
Jovan Nikolić, Nursultan Jubatyrov, Evangelos Pournaras
Large-scale decentralized systems of autonomous agents interacting via asynchronous communication often experience the following self-healing dilemma: fault detection inherits network uncertainties making a remote faulty process indistinguishable from a slow process. In the case of a slow process without fault, fault correction is undesirable as it can trigger new faults that could be prevented with fault tolerance that is a more proactive system maintenance. But in the case of an actual faulty process, fault tolerance alone without eventually correcting persistent faults can make systems underperforming. Measuring, understanding and resolving such self-healing dilemmas is a timely challenge and critical requirement given the rise of distributed ledgers, edge computing, the Internet of Things in several energy, transport and health applications. This paper contributes a novel and general-purpose modeling of fault scenarios during system runtime. They are used to accurately measure and predict inconsistencies generated by the undesirable outcomes of fault correction and fault tolerance as the means to improve self-healing of large-scale decentralized systems at the design phase. A rigorous experimental methodology is designed that evaluates 696 experimental settings of different fault scales, fault profiles and fault detection thresholds in a prototyped decentralized network of 3000 nodes. Almost 9 million measurements of inconsistencies were collected in a network, where each node monitors the health status of another node, while both can defect. The prediction performance of the modeled fault scenarios is validated in a challenging application scenario of decentralized and dynamic in-network data aggregation using real-world data from a Smart Grid pilot project. Findings confirm the origin of inconsistencies at design phase and provide new insights how to tune self-healing at an early stage. Strikingly, the aggregation accuracy is well predicted as shown by high correlations and low root mean square errors.
Jovan Nikolić, Nursultan Jubatyrov, Evangelos Pournaras
Large-scale decentralized systems of autonomous agents interacting via\nasynchronous communication often experience the following self-healing dilemma:\nfault detection inherits network uncertainties making a remote faulty process\nindistinguishable from a slow process. In the case of a slow process without\nfault, fault correction is undesirable as it can trigger new faults that could\nbe prevented with fault tolerance that is a more proactive system maintenance.\nBut in the case of an actual faulty process, fault tolerance alone without\neventually correcting persistent faults can make systems underperforming.\nMeasuring, understanding and resolving such self-healing dilemmas is a timely\nchallenge and critical requirement given the rise of distributed ledgers, edge\ncomputing, the Internet of Things in several energy, transport and health\napplications. This paper contributes a novel and general-purpose modeling of\nfault scenarios during system runtime. They are used to accurately measure and\npredict inconsistencies generated by the undesirable outcomes of fault\ncorrection and fault tolerance as the means to improve self-healing of\nlarge-scale decentralized systems at the design phase. A rigorous experimental\nmethodology is designed that evaluates 696 experimental settings of different\nfault scales, fault profiles and fault detection thresholds in a prototyped\ndecentralized network of 3000 nodes. Almost 9 million measurements of\ninconsistencies were collected in a network, where each node monitors the\nhealth status of another node, while both can defect. The prediction\nperformance of the modeled fault scenarios is validated in a challenging\napplication scenario of decentralized and dynamic in-network data aggregation\nusing real-world data from a Smart Grid pilot project. Findings confirm the\norigin of inconsistencies at design phase.\n
Henry Kim, Hjalmar Turesson, Marek Laskowski, Amir Fard Bahreini
Blockchains can be public, permissionless networks implementing novel cryptocurrency-based technology features or permissioned, interorganizational networks championed by industry consortia. Some ventures operationalize a hybrid of these two network types to enhance adoption of their blockchain platforms by broadening their base of stakeholders or facilitating interoperability between heterogeneous blockchains. In this article, we synthesize literature and industry writings to identify four hybrid blockchain architectures: hybrid blockchain approach, connected hybrid blockchain, interoperable blockchain architecture, and hard-forked blockchain for enterprise use. We then analyze these architectures along dimensions of semantic modeling support between private and public networks, data connectivity between networks, syntactic interoperability support between networks with heterogeneous codebases, governance model, and technical features. We find that hybrid blockchain ventures make trade-offs: support API's, tools, and customized development so that a codebase is useful for private and public networksorprovide such support for interoperation between heterogeneous codebases. We then conduct a case study of an exemplar for a hybrid blockchain approach, the startup Insolar. We identify characteristics that have led Insolar to be idiosyncratically agile and effective in its blockchain development, which together with our architecture analysis may be timely and prescriptive as enterprises grow interested in addressing blockchain hybridity and interoperability.
Philipp Frauenthaler, Michael Borkowski, Stefan Schulte
The suitability of a blockchain for a given use case mainly depends on the user's requirements and on the blockchain's functional and non-functional properties. Requirements and a blockchain's properties may change over time, and thus, a selected blockchain may become unsuitable for a given use case. Such uncertainties pose significant risks for developers. In this paper, we present a framework that allows developers to define functional and non-functional requirements, monitors several blockchains and, based on the specified requirements, selects the best-fitting blockchain for a particular use case. If another blockchain becomes more appropriate during runtime, the framework enables a switchover to this blockchain. Our evaluation using a reference implementation shows that switching to another blockchain can save cost and enable developers to benefit from better performance and a higher level of trust.
Ilham Qasse, Josef Spillner, Manar Abu Talib, Qassim Nasir
Repositories are important indicators for liveness and maturity in software development communities. They host user-facing applications or re-usable artefacts to build such applications. While rarely decentralised themselves, they are important for hosting code for decentralized applications. In this study, we investigate public repositories dedicated to decentralised applications, or ĐApps, executing on heterogeneous blockchain platforms. The study is the first to report aggregated metrics on the repository-level and application-level characteristics including ĐApps metadata, associated smart contracts composition and inconsistencies between repositories in both schema and content. The main contributions are data acquisition tools and an evolving public dataset along with an initial analysis to derive key metrics in a reproducible way. Insights provided encompass the dominance of Ethereum, the absence of smart contracts for a significant portion of applications, and unused application advertisement potential by absence from popular repositories. The insights can be exploited by developers to build high-quality and highly popular applications and set up corresponding quality checks.
Blockchain is viewed as one of the most promising and disruptive inventions and is considered to have the potential to significantly change current auditing profession and reshape the business ecosystem. With the advancement of blockchain, it has been concerned in some studies that auditing could be significantly impacted and eventually replaced. Meanwhile, another viewpoint argues that blockchain technology would push the existing auditing industry to a new direction rather than eliminating the need for auditing in the immediate future. This discussion can hardly be settled without evaluation, however, studies exploring how blockchain technology can be employed in auditing practice or how continuous auditing can be conducted using blockchain technology are limited. This paper analyses the impact of blockchain features on existing audit processes and discusses the possibility of applying blockchain characteristics including immutability, distributed ledger, real-time settlement to the auditing domain. Based on the systematic analysis, this study proposes a conceptual model for blockchain-based auditing information system, which provides solutions to employ blockchain technology in auditing profession, significantly improving the efficiency and effectiveness of auditing and promoting the transformation of the auditing paradigm to real-time, continuous and intelligent auditing.
Recently, the term “Internet of Things” (IoT) has elicited escalating attention. The flexibility, agility, and ubiquitous accessibility have encouraged the integration between machine learning (ML) with IoT. However, there are many challenges that present the key inhibitors in moving ML to the public solution, such as centralized training, poor training efficiency, and heavy computing capabilities requirements. Therefore, bringing learning intelligence to edge IoT nodes has been spotlighted for some researches. Meanwhile, how to govern the use of learning results efficiently, reliably, scalably, and safely is hampered by the heterogeneity and nonconfidence among IoT nodes. In this article, we propose a blockchain-based collective Q-learning (CQL) approach to address the above issues, where lightweight IoT nodes are used to train parts of learning layers, then employing blockchain to share learning results in a verifiable and permanent manner. We further improve the traditional Proof of Work (PoW). Instead of solving a meaningless puzzle, we regard the learning process in the IoT node as a piece of work. Accordingly, the winner is the IoT node with the minimum reduced percentage of the learning loss function, referred to as the Proof-of-Learning (PoL) consensus protocol. Specifically, in order to show how the CQL approach works, we use it to address a networking integrated cloud-edge-end resource allocation in IoT. The experimental results reveal the superior performance of the proposed scheme.
This paper intends to propose the architecture of a blockchain-agnostic\nprotocol designed for communication of blockchains amongst each other (i.e.\ncross-chain), and for blockchains with the outside world (i.e. data oracles).\nThe expansive growth of cutting-edge technology in the blockchain industry\noutlines the need and opportunity for addressing oracle consensus in a manner\nboth technologically and economically efficient as well as futureproof.\nBlockchain-agnosticism is inherently limited if proposing a technological\nsolution involves adding one more architectural layer. As such, Gravity\nprotocol is designed to be a truly blockchain-agnostic protocol. By ensuring\nparity through direct integration and by leveraging the stability and security\nof the respective interconnected ecosystems, Gravity circumvents the need for a\ndedicated, public blockchain and a native token. Ultimately, Gravity protocol\nintends to address scalability challenges by providing a solid infrastructure\nfor the creation of gateways, cross-chain applications, and sidechains. This\npaper introduces and defines the concept of Oracle Consensus and its\nimplementation in the Gravity protocol named the Pulse Consensus algorithm. The\nproposed consensus architecture allows Gravity to be considered a singular\ndecentralized blockchain-agnostic oracle.\n