R.L. Kashyap, Karishma Arora, Mohak Dwarkadhish Sharma, A. Aazam
Achieving good performance in terms of throughput and scalability, with high quality of security has always been a challenging problem in all sorts of scheduling. Permissioned blockchain allows multiple contracts of non-trusting peer organization to be deployed for working in consortium. It is the responsibility of the scheduler often called as an ordering service to form block of transactions to get committed through consensus. Practical Byzantine Fault Tolerance (PBFT) is one of the most popular consensus algorithm used in current implementations of blockchain. Most consensus algorithms including PBFT follow FIFO scheduling strategy to create the block of transactions. With block chain being supported for multi-contract environment, scheduling should consider difference in service requirements specifically security requirement for heterogeneous contracts. The current work proposes SAGA-PBFT (Security-Aware Genetic Algorithm based Practical Byzantine fault Tolerance) scheduler, which uses multi objective genetic algorithm for balancing the security requirement and security overhead at the time of block creations. The algorithm assigns the security level to each transaction as per its security requirement but in an unpredictable manner making security attack difficult. It further uses security aware PBFT for consensus. Experimental simulation proves that SAGA-PBFT when compared with PBFT, achieves better commit time and scalability with best possible security.
Oleksandr Anyshchenko, Ivan Bohuslavskyi, Stanislav Kruglik, Yash Madhwal · 6 authors
Blockchain technology has a lot of applications including but not limited to cryptotokens. For example, permissioned blockchains for state registries can include no money logic inside. But the creation of cryptotoken is a typical example of blockchain application and is a popular model to measure performance. In this paper, we described how to construct an account-based cryptotoken using Exonum, an open-source framework for creating blockchain applications, and by the means of performance tests shown that the proposed solution meets real-life throughput requirements for many applications. The proposed approach can be used to create cryptocurrencies in other open-source frameworks focused on permissioned blockchain applications.
Distributed Ledger Technology (DLT), also known as „Blockchain”, represents a new paradigm in how applications are designed and built. Even thoughthe blockchain emerged as a consumer-focused technology (form Bitcoin), it’s adoptionin the enterpriseenvironment has increased dramatically in the last years. The user’sfocus on privacy, security and transparency has motivated corporations to invest in distributed applications throughout their structure and operations. The main frameworks for enterprise blockchain solutions are coming from well established IT&C corporations like Microsoft (partnership with Ethereum), IBM (Hyperledger Fabric), JP Morgan (Quorum) and others.The blockchain technology is pretty new, and it cannot fully replace legacy centralized cloud-based solutions. The scalability issue of DLT is well-known, as the most advanced blockchain technologies can only process a few hundred transactions per second. This is nowhere near the speed of Visa’s payment system that can process more than 2000 transactions per second.
Hye-Yeong Shin, Daeyong Kim, Soohoon Maeng, Kiyoung Lee · 5 authors
Most of the existing platform for Bitcoin data analysis or visualization, they perform data collection from one node in the main-net. Thus we can notice some differences in their provided data. In this research, and in order to provide global data visualization, we collect both the historical and realtime Bitcoin data. Our monitoring system is comprised of three main components; multiple full Bitcoin nodes were used to collect data, the analysis of data was done by the Analytic Engine, while the webserver was used to visualize both row-data and analyzed data.
Bitcoin is a peer-to-peer payment system proposed by Nakamoto in 2008. The bitcoin backbone protocol has been analyzed in some depth: the blockchain growth property quantifies the number of blocks added to the blockchain during any time intervals; the blockchain quality property ensures the honest miners always contribute at least a certain fraction of the blockchain; the common prefix property ensures if a block is deep enough, it must be adopted by all honest miners with high probability. The Prism protocol was recently proposed to dramatically improve the blockchain throughput while maintaining the same level of security. Prior analyses of the bitcoin and Prism backbone protocols assume the lifespan of blockchain is finite. This paper presents a streamlined and strengthened analysis in synchronous networks without the finite lifespan assumption. Specifically, the results include a blockchain growth property, a blockchain quality property, and a common prefix property of the bitcoin backbone protocol, as well as the liveness and persistence of the Prism backbone protocol regardless of whether the blockchains have finite lifespan. The properties take the form of explicit expressions in lieu of order optimal results.
Huan Zhou, Xue Ouyang, Jinshu Su, Cees de Laat · 5 authors
There lacks trust between the cloud customer and provider to enforce traditional cloud SLA (Service Level Agreement) where the blockchain technique seems a promising solution. However, current explorations still face challenges to prove that the off-chain SLO (Service Level Objective) violations really happen before recorded into the on-chain transactions. In this paper, a witness model is proposed implemented with smart contracts to solve this trust issue. The introduced role, "Witness", gains rewards as an incentive for performing the SLO violation report, and the payoff function is carefully designed in a way that the witness has to tell the truth, for maximizing the rewards. This fact that the witness has to be honest is analyzed and proved using the Nash Equilibrium principle of game theory. For ensuring the chosen witnesses are random and independent, an unbiased selection algorithm is proposed to avoid possible collusions. An auditing mechanism is also introduced to detect potential malicious witnesses. Specifically, we define three types of malicious behaviors and propose quantitative indicators to audit and detect these behaviors. Moreover, experimental studies based on Ethereum blockchain demonstrate the proposed model is feasible, and indicate that the performance, ie, transaction fee, of each interface follows the design expectations.
A decentralized private Blockchain implementation for academic document storage and document verification can add self-sovereignty to the process. It can dramatically minimize the time and cost of verification at various layers of verification. Blockchain would remove all the layers at all and it will provide immediate auditing of any document. So, the request and response will be truly real time in our case.Apart from speeding up the verification process, it will also increase the security of personal education data and will check all kind of misuse also. Putting documents on Blockchain would increase the security, because all the data would only be accessible by private key and proper authentication to that private key.We are proposing a private Blockchain that would be managed by some private vendors and only those vendors will take part in consensus. So, we are using proof of stake consensus in our case. We are using private IPFS database server for storing our documents over Blockchain. We are considering Ethereum Blockchain ecosystem in our case. Alternatively we can also use Hyperledger Fabric for implementation but that discussion is out of the scope for current document.
Michelle-Christine Steiner, Jonas Kampik, Markus Küch, Christian Rehtanz · 5 authors
This paper proposes potential applications for Distributed Ledger Technologies (DLT) in the balancing energy market. Starting with illustrating the state of the art of DLT, analyzing the advantages and disadvantages and carrying out a comparison of the different concepts Blockchain, Tangle and Hashgraph. In addition, the structure of the process behind the balancing energy market is investigated and presented. Furthermore, the identification of potential applications for DLT in the balancing market is carried out. The basis for this is the execution and analysis of expert interviews and an analysis of publicly available documents.
Blockchain interoperability, which allows state transitions across different\nblockchain networks, is critical functionality to facilitate major blockchain\nadoption. Existing interoperability protocols mostly focus on atomic token\nexchange between blockchains. However, as blockchains have been upgraded from\npassive distributed ledgers into programmable state machines (thanks to smart\ncontracts), the scope of blockchain interoperability goes beyond just token\nexchange. In this paper, we present HyperService, the first platform that\ndelivers interoperability and programmability across heterogeneous blockchains.\nHyperService is powered by two innovative designs: (i) a developer-facing\nprogramming framework that allows developers to build cross-chain applications\nin a unified programming model; and (ii) a secure blockchain-facing\ncryptography protocol that provably realizes those applications on blockchains.\nWe implement a prototype of HyperService in about 35,000 lines of code to\ndemonstrate its practicality. Our experiment results show that HyperService\nimposes reasonable latency, in order of seconds, on the end-to-end execution of\ncross-chain applications\n
Abstract South Korea invests a budget of trillions in national R&D projects every year, and has achieved excellent performance doing so each year. However, since the projects are planned, evaluated, and managed by different departments and institutions, duplicate planning and submission leads to insufficient sharing of research results. Currently, the National Technology Information Service (NTIS) inspects project duplication based on keywords, which leads to duplicate planning among departments and closed management of research results. Since the NTIS builds in centralized systems, the inspection systems supports one-way management for duplication checking and information sharing. Therefore, we propose a new platform, called the Trusted Information Project Platform (TIP-Platform), for easily checking for project duplication, sharing research results, and updating research results. TIP-Platform adopts a new concept for user authority setting, the distributed ledger structure, transaction structure, and service. For the adaption, the TIP-Platform uses blockchain technology that performs recording and management via blocks by distributing the right to record and managing transactions. This platform makes it easy for anyone to view and use project-related information such as research results and duplication review. In this paper, we describe how the TIP-Platform can achieve excellent research results through information sharing of a project. This platform needs to be based on trust, because it shares information and continually updates information.
Aug 9, 2019·Proceedings of the 2019 27th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering
Used as a platform for executing smart contracts, Blockchain technology has yielded new programming languages. We propose a graph-based framework for computing software design metrics for the Solidity programming language, and use this framework in a preliminary study on 505 smart contracts mined from GitHub. The results show that most of the smart contracts are rather straightforward from an objected-oriented point of view and that new design metrics specific to smart contracts should be developed.
Efficient and secure resource discovery in the inter-cloud remains non-trivial, especially in non-federated environments. It involves balancing conflicting requirements in a dynamic multi-party scenario based on multi-factor optimization while overcoming security concerns. Various P2P based resource discovery schemes for the inter-cloud environment have been proposed by researchers but challenges including efficient resource discovery and selection, trust/reputation management, transaction record management and seamless financial settlements persist. We propose a Blockchain-based Inter-cloud Resource Discovery (BIRD) framework for the non-federated inter-cloud model which addresses the shortcomings of existing approaches. It is the first demonstration of using the blockchain idea to the inter-cloud resource discovery process alleviating the need of a trusted third-party or broker between participating cloud service providers (CSPs), while ensuring optimal and secure resource discovery and selection.
Aug 1, 2019·2019 IEEE Intl Conf on Dependable, Autonomic and Secure Computing, Intl Conf on Pervasive Intelligence and Computing, Intl Conf on Cloud and Big Data Computing, Intl Conf on Cyber Science and Technology Congress (DASC/PiCom/CBDCom/CyberSciTech)
When banks loan to small and micro enterprises, they are faced with higher credit costs and difficulties in controlling risks. Blockchain provides a distributed infrastructure for business connectivity across organizations. Blockchain is a consensus, traceable, tamper-proof, final shared data ledger. Blockchain not only improves the efficiency of data connections, but also promotes the credible flow of data. In this background, we propose Bis: a Novel Blockchain based Bank-tax interaction system in smart city. We have designed the total scheme, and the tax bureau can use blockchain to build bank-tax interactive system. Most commercial banks can obtain the enterprises tax information in an efficient and safe way through multi-channels technology of Blockchain. We carried out system development and experiments to prove that our Bis system can solve enterprise tax data sharing and business connection problems across enterprises, tax bureau and banks.
With the deepening of research on Bitcoin privacy protection, Bitcoin, a new type of digital currency, has become more difficult to regulate. A Bitcoin privacy protection confusion scheme with regulatory RBmix is proposed for this problem. The model of RBmix uses a fair blind signature algorithm and introduces trusted third parties with regulatory, anonymity, scalability, Bitcoin compatibility, and anti-DoS aggression. Experimental results show that the RBmix protocol has good scalability and execution efficiency.
Abstract In the blockchain system, the consensus mechanism not only helps the nodes maintain data consistency, but also has certain functions for token issuance and attack prevention. Aiming at the problems of low enthusiasm and weak centralization in Delegated Proof of Stake (DPoS), this paper proposes a weak centralization consensus mechanism with more incentive effect. We replace the voting link with opportunity verification mechanism, and make the voting link that affects the enthusiasm of nodes become the embodiment of their own rights and interests, so as to strive for the maximization of their own interests. And we also introduce the method of random guess to make the selection of representative nodes more random, so as to achieve the situation of weaker center. At last, combined with the existing problems, the paper analyses the feasible solution with this mechanism.
Jelena Mišić, Vojislav B. Mišić, Xiaolin Chang, Saeideh G. Motlagh · 5 authors
In this paper, we provide a comprehensive analytical model for Bitcoin's blockchain distribution network. Components of the model are derived from recent measurements and business analysis reports. We model the data distribution algorithm using branching processes in the network with random distribution of node connectivity. Then, we apply Jackson network model to the entire network in which individual nodes operate as priority M/G/1 queuing systems. Data arrival to the nodes is modeled as a non-homogeneous Poisson process where the distribution of arrival rate to the nodes is derived from the analytical model of data delivery protocol. Within performance results, we present probability distributions of block and transaction distribution time, node response time, forking probabilities, network partition sizes, and duration of ledger's inconsistency period.
Research and apply blockchain technologies for e-commerce, finance and energy. The blockchain system includes blockchain technology components, blockchain application programming interfaces, and applications. The blockchain-based applications cover supply chain finance, e-commerce transactions, product traceability, user credits, financial services, trust systems, new energy, etc. Based on blockchain technology, it builds a creative and security trading system, payment system and trust system for e-commerce, financial services and new energy business.
Aleksandr Zavodovski, Nitinder Mohan, Walter Wong, Jussi Kangasharju
High demand for low latency services and local data processing has given rise for edge computing. As opposed to cloud computing, in this new paradigm computational facilities are located close to the end-users and data producers, on the edge of the network, hence the name. The critical issue for the proliferation of edge computing is the availability of local computational resources. Major cloud providers are already addressing the problem by establishing facilities in the proximity of end-users. However, there is an alternative trend, namely, developing open infrastructure as a set of standards, technologies, and practices to enable any motivated parties to offer their computational capacity for the needs of edge computing. Open infrastructure can give an additional boost to this new promising paradigm and, moreover, help to avoid problems for which cloud computing has been long criticized for, such as vendor lock-in or privacy. In this paper, we discuss the challenges related to creating such an open infrastructure, in particular focusing on the applicability of distributed ledgers for contractual agreement and payment. Solving the challenge of contracting is central to realizing an open infrastructure for edge computing, and in this paper, we highlight the potential and shortcomings of distributed ledger technologies in the context of our use case.
Cryptocurrencies, implemented with blockchain protocols, promise to become a global payment system if they can overcome performance limitations. Rapidly advancing architectures improve on latency and throughput, but most require all participating servers to process all transactions. Several recent works propose to shard the system, such that each machine would only process a subset of the transactions. However, we identify a denial-of-service attack that is exposed by these solutions - an attacker can generate transactions that would overload a single shard, thus delaying processing in the entire system. Moreover, we show that in common scenarios, these protocols require most node operators to process almost all blockchain transactions. We present Ostraka, a blockchain node architecture that shards (parallelizes) the nodes themselves. We prove that replacing a unified node with an Ostraka node does not affect the security of the underlying consensus mechanism. We evaluate analytically and experimentally block propagation and processing in various settings. Ostraka allows nodes in the network to scale, without costly coordination. In our experiments, Ostraka nodes' transaction processing rate grows linearly with the addition of resources.
Julio Moreno, Eduardo B. Fernández, Eduardo Fernández‐Medina, Manuel Serrano
Big Data is changing the perspective on how to obtain valuable information from data stored by organizations of all kinds. By using these insights, companies can make better decisions and thus achieve their business goals. However, each new technology can create new security problems, and Big Data is no exception. One of the major security issues in a Big Data ecosystem is what level of trust in data and data sources stakeholders can have: without reliable data, the results of data analysis lose value. In this paper, we propose a security pattern to improve traceability and veracity of data through the use of Blockchain technologies. In this pattern, Blockchain will be used as a distributed ledger where all operations performed on the data will be registered. Therefore, the veracity of the data will increase, as will the confidence in the insights obtained from the analysis. The purpose of this paper is to help Chief Security Officer and Big Data architects incorporate this mechanism to improve the security of their environment.
Dhanya Therese Jose, Antorweep Chakravorty, Chunming Rong
Conventional methods for data analysis demands data be moved across networks for analysis. Along with it being highly network intensive, data owners are also reluctant to provide their data due to security and privacy breaches. In order to overcome these issues, we proposed TOTEM: Token for controlled computation, that combines both blockchain technologies and big data systems. The objective is to allow computation to be taken to the data, rather than moving the data to the computation. A third-party user uses the TOTEM SDK to create a MapReduce code for computation, which will be executed within the data owner's environment. This computational system prevents the execution of any malicious functions in the user code, by putting constraints on computational operations. A pre-defined totem will be assigned to authorised users, based on their computational needs. A smart contract performs pre-checks on user-submitted code and associated totem value, by using a totem estimator to determine the required totem for executing the given code. A Totem manager and updater is introduced to coordinate computation of user code until it exits gracefully, or the assigned totem gets exhausted. The TOTEM project ensures data security by allowing organisations to open their data centers and allow disruptive business models.