14 research outputs found

    Dynamically Adjusting the Mining Capacity in Cryptocurrency with Binary Blockchain

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    Many cryptocurrencies rely on Blockchain for its operation. Blockchain serves as a public ledger where all the completed transactions can be looked up. To place transactions in the Blockchain, a mining operation must be performed. However, due to a limited mining capacity, the transaction confirmation time is increasing. To mitigate this problem many ideas have been proposed, but they all come with own challenges. We propose a novel parallel mining method that can adjust the mining capacity dynamically depending on the congestion level. It does not require an increase in the block size or a reduction of the block confirmation time. The proposed scheme can increase the number of parallel blockchains when the mining congestion is experienced, which is especially effective under DDoS attack situation. We describe how and when the Blockchain is split or merged, how to solve the imbalanced mining problem, and how to adjust the difficulty levels and rewards. We then show the simulation results comparing the performance of binary blockchain and the traditional single blockchain

    A Byzantine Fault-Tolerant Ordering Service for the Hyperledger Fabric Blockchain Platform

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    Hyperledger Fabric (HLF) is a flexible permissioned blockchain platform designed for business applications beyond the basic digital coin addressed by Bitcoin and other existing networks. A key property of HLF is its extensibility, and in particular the support for multiple ordering services for building the blockchain. Nonetheless, the version 1.0 was launched in early 2017 without an implementation of a Byzantine fault-tolerant (BFT) ordering service. To overcome this limitation, we designed, implemented, and evaluated a BFT ordering service for HLF on top of the BFT-SMaRt state machine replication/consensus library, implementing also optimizations for wide-area deployment. Our results show that HLF with our ordering service can achieve up to ten thousand transactions per second and write a transaction irrevocably in the blockchain in half a second, even with peers spread in different continents

    SeedChain:a secure and transparent blockchain-driven framework to revolutionize the seed supply chain

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    Farming is a major sector required for any nation to become self-sustainable. Quality seeds heavily influence the effectiveness of farming. Seeds cultivated by breeders pass through several entities in order to reach farmers. The existing seed supply chain is opaque and intractable, which not only hinders the growth of crops but also makes the life of a farmer miserable. Blockchain has been widely employed to enable fair and secure transactions between farmers and buyers, but concerns related to transparency and traceability in the seed supply chain, counterfeit seeds, middlemen involvement, and inefficient processes in the agricultural ecosystem have not received enough attention. To address these concerns, a blockchain-based solution is proposed that brings breeders, farmers, warehouse owners, transporters, and food corporations to a single platform to enhance transparency, traceability, and trust among trust-less parties. A smart contract updates the status of seeds from a breeder from to . Then, a non-fungible token (NFT) corresponding to approved seeds is minted for the breeder, which records the date of cultivation and its owner (breeder). The NFT enables farmers to keep track of seeds right from the date of their cultivation and their owner, which helps them to make better decisions about picking seeds from the correct owner. Farmers directly interact with warehouses to purchase seeds, which removes the need for middlemen and improves the trust among trust-less entities. Furthermore, a tender for the transportation of seeds is auctioned on the basis of the priority location , Score, and bid_amount of every transporter, which provides a fair chance to every transporter to restrict the monopoly of a single transporter. The proposed system achieves immutability, decentralization, and efficiency inherently from the blockchain. We implemented the proposed scheme and deployed it on the Ethereum network. Smart contracts deployed over the Ethereum network interact with React-based web pages. The analysis and results of the proposed model indicate that it is viable and secure, as well as superior to the current seed supply chain system

    Window Based BFT Blockchain Consensus

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    There is surge of interest to the blockchain technology not only in the scientific community but in the business community as well. Proof of Work (PoW) and Byzantine Fault Tolerant (BFT) are the two main classes of consensus protocols that are used in the blockchain consensus layer. PoW is highly scalable but very slow with about 7 (transactions/second) performance. BFT based protocols are highly efficient but their scalability are limited to only tens of nodes. One of the main reasons for the BFT limitation is the quadratic O(n2)O(n^2) communication complexity of BFT based protocols for nn nodes that requires n×nn \times n broadcasting. In this paper, we present the {\em Musch} protocol which is BFT based and provides communication complexity O(fn+n)O(f n + n) for ff failures and nn nodes, where f<n/3f < n/3, without compromising the latency. Hence, the performance adjusts to ff such that for constant ff the communication complexity is linear. Musch achieves this by introducing the notion of exponentially increasing windows of nodes to which complains are reported, instead of broadcasting to all the nodes. To our knowledge, this is the first BFT-based blockchain protocol which efficiently addresses simultaneously the issues of communication complexity and latency under the presence of failures.Comment: 2018 IEEE International Conference on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData

    D1.3 - SUPERCLOUD Architecture Implementation

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    In this document we describe the implementation of the SUPERCLOUD architecture. The architecture provides an abstraction layer on top of which SUPERCLOUD users can realize SUPERCLOUD services encompassing secure computation workloads, secure and privacy-preserving resilient data storage and secure networking resources spanning across different cloud service providers' computation, data storage and network resources. The components of the SUPERCLOUD architecture implementation are described. Integration between the different layers of the architecture (computing security, data protection, network security) and with the facilities for security self-management is also highlighted. Finally, we provide download and installation instructions for the released software components that can be downloaded from our common SUPERCLOUD code repository

    Feature trade-off analysis for reconnaissance detection.

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    An effective cyber early warning system (CEWS) should pick up threat activity at an early stage, with an emphasis on establishing hypotheses and predictions as well as generating alerts on (unclassified) situations based on preliminary indications. The design and implementation of such early warning systems involve numerous challenges such as generic set of indicators, intelligence gathering, uncertainty reasoning and information fusion. This chapter begins with an understanding of the behaviours of intruders and then related literature is followed by the proposed methodology using a Bayesian inference-based system. It also includes a carefully deployed empirical analysis on a data set labelled for reconnaissance activity. Finally, the chapter concludes with a discussion on results, research challenges and necessary suggestions to move forward in this research line

    Securing configuration, management and migration of virtual network functions using blockchain

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    The current technologies of network functions virtualization and network service function chaining increase service provision agility and add intelligence at the core of the network. However, the network core programmability and the provision of services by multiple providers brings new vulnerabilities to this scenario. The need for secure provisioning of virtual network service functions (VNFs) becomes even more critical, since simple modifications at the network core can affect multiple network users. This work proposes a blockchain-based architecture for secure management, configuration and migration of VNFs. This architecture ensures the immutability, non-repudiation, and auditability of VNF configuration and the management histories. In addition, the proposed architecture preserves the anonymity of VNFs, tenants, and configuration information, to mitigate the possibilities of targeted attack. A prototype designed for the OPNFV (Open Platform for NFV) platform was developed, and the proposed architecture performance was evaluated in terms of parameters trade-offs and bottlenecks.As tecnologias de virtualização de funções de rede e de encadeamento de funções de serviço de rede aumentam a agilidade na provisão de serviços e acrescentam inteligência no núcleo da rede. No entanto, a programabilidade do n´núcleo da rede e a oferta de serviços por múltiplos fornecedores provocam novas vulnerabilidades neste ambiente. A necessidade de provisão de funções virtuais de serviço de rede (VNFs) seguras torna-se ainda mais crítica, uma vez que uma simples modificação no núcleo da rede pode afetar múltiplos usuários. Este trabalho propõe uma arquitetura baseada em correntes de blocos para gerenciamento seguro, configuração emigração de VNFs. Esta arquitetura garante a imutabilidade, não repúdio e auditabilidade da configuração de VNF e do histórico de gerenciamento de VNFs. Além disso, a arquitetura proposta preserva o anonimato das VNFs, dos inquilinos e das informações de configuração, a fim de evitar que estes se tornem alvos de ataques. Foi desenvolvido um protótipo concebido para a plataforma OPNFV (Open Platform for NFV) e foi avaliado o desempenho em relação ao custo benefício de parâmetros e aos gargalos da arquitetura proposta
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