In this paper, We studied the operation of distributed ledger technology used as a core technology for smart contracts and the components of distributed ledger technology. As a solution applying the entity of distributed ledger technology to NoE, we proposed the protocol of the distributed ledger technology using the thing user social group management function of NoE protocols being standardized in ISO/IEC JTC1 SC6. The management function of things user social group in NoE provides stable protocol functions and data transmission management, and provides group management functions such as member discovery function and data transmission channel management function. It is expected to be useful for member management functions of distributed ledger nodes by providing a service that apply the component of distributed ledger technology. We intend to actively reflect this technology in the future network functions of ISO/IEC JTC1 SC6, which is undergoing standardization.
Open access
Caching and Content Delivery
Internet of Things and Social Network Interactions
Mikel Cortes-Goicoechea, Luca Franceschini, Leonardo Bautista-Gomez
Scalability is a common issue among the most used permissionless blockchains, and several approaches have been proposed accordingly. As Ethereum is set to be a solid foundation for a decentralized Internet web, the need for tackling scalability issues while preserving the security of the network is an important challenge. In order to successfully deliver effective scaling solutions, Ethereum is on the path of a major protocol improvement called Ethereum 2.0 (Eth2), which implements sharding. As the change of consensus mechanism is an extremely delicate matter, this improvement will be achieved through different phases, the first of which is the implementation of the Beacon Chain. For this, a specification has been developed and multiple groups have implemented clients to run the new protocol. In this work, we analyse the resource usage behaviour of different clients running as Eth2 nodes, comparing their performance and analysing differences. Our results show multiple network perturbations and how different clients react to it.
Achieving the equilibrium between scalability, sustainability, and security while keeping decentralization has prevailed as the target solution for decentralized blockchain applications over the last years. Several approaches have been proposed by multiple blockchain teams to achieve it, Ethereum being among them. Ethereum is on the path of a major protocol improvement called Ethereum 2.0 (Eth2), implementing Sharding and introducing the Proof-of-Stake (PoS). As the change of consensus mechanism is a delicate matter, this improvement will be achieved through different phases, the first of which is the implementation of the Beacon Chain. As Ethereum1, Eth2 relies on a decentralized peer-to-peer (p2p) network for the message distribution. Up to date, we estimate that there are around 5.000 nodes in the Eth2 main net geographically distributed. However, the topology of this one still prevails unknown. In this paper, we present the results obtained from the analysis we performed on the Eth2 p2p network. Describing the topology of the network, as possible hazards that this one implies.
The Internet of Things (IoT) providers serve better IoT services each year while producing more IoT gateways and devices to expand their services. However, the security of the IoT ecosystem remains an afterthought for most IoT providers. This action results in many cybersecurity breaches in the field, most likely due to the lack of access control mechanisms. In this paper, we propose BorderChain, an access control framework based on blockchain for IoT endpoints. The security protocol guarantees two properties. First, our proposal assures IoT users and services that they communicate with approved IoT gateways as endpoints, holding verified IoT devices that they need. Second, BorderChain also generates access tokens that the IoT service and users can use to query IoT resources legitimately inside the IoT domains. As a result, the protocol can convince IoT domain owners that the system will only authorize IoT requests that they approve. We realize our protocol in the form of a smart contract to allow many IoT entities such as IoT domain owners, IoT devices, IoT gateways, IoT vendors, IoT services, IoT users, and Internet Service Provider (ISP) to collaborate in a unified environment. We then implement entities in BorderChain as Node JS applications connecting to the Ethereum blockchain as our peer-to-peer platform. Based on our performance evaluation using several Raspberry Pi hardware and our private server, we show that BorderChain can process entities' authentication and authorization requests efficiently using all hardware resources. Finally, we release BorderChain for public use.
Lightning Network (LN) addresses the scalability problem of Bitcoin by leveraging off-chain transactions. Nevertheless, it is not possible to run LN on resource-constrained IoT devices due to its storage, memory, and processing requirements. Therefore, in this paper, we propose an efficient and secure protocol that enables an IoT device to use LN's functions through a gateway LN node. The idea is to involve the IoT device in LN operations with its digital signature by replacing original 2-of-2 multisignature channels with 3-of-3 multisignature channels. Our protocol enforces the LN gateway to request the IoT device's cryptographic signature for all operations on the channel. We evaluated the proposed protocol by implementing it on a Raspberry Pi for a toll payment scenario and demonstrated its feasibility and security.
Blockchain technology has enabled the keeping of a decentralized, tamper-proof, immutable, and ordered ledger of transactional events. Efforts to leverage such a ledger may be challenging when data storage requirements exceed most blockchain protocols' current capacities. Storing large amounts of decentralized data while maintaining system efficiency is the challenge that we target. This paper proposes using the IPFS distributed hash table (DHT) technology to store information immutably and in a decentralized manner to mitigate the high cost of storage. A storage system involving blockchain and other storage systems in concert should be based on immutable data and allow removal of data from malicious users in the DHT. Efficiency is improved by decreasing the overall processing time in the blockchain with the help of DHT technology and introducing an agreement service that communicate with the blockchain via a RESTful API. We demonstrate the applicability of the proposed method and conclude that the combination of IPFS and blockchain provides efficient cryptographic storage, immutable history and overall better efficiency in a decentralized manner.
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.
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.
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.
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.
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.
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.
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.
For a blockchain, consensus is the foundation protocol that enables cryptocurrencies such as Bitcoin to maintain state. Additionally, to ensure safety and liveness for a publicly accessible and verifiable ledger, fault tolerance must be robust. However, there appears to be a degree of misunderstanding about how consensus is applied across blockchains. To assist researchers considering variations between them, this study presents a rational classification of consensus methods applied to current blockchains. The study provides a survey of 19 methods classified by the scarce resource they employ: clock-cycles, bits, tokens, votes, time, and biometrics. Blockchain implementations are split between consensus algorithms requiring proof of resource and those that use majority voting to update the ledger.
Divija Swetha Gadiraju, V. Lalitha, Vaneet Aggarwal
Blockchain is a distributed ledger with wide applications. Due to the\nincreasing storage requirement for blockchains, the computation can be afforded\nby only a few miners. Sharding has been proposed to scale blockchains so that\nstorage and transaction efficiency of the blockchain improves at the cost of\nsecurity guarantee. This paper aims to consider a new protocol,\nSecure-Repair-Blockchain (SRB), which aims to decrease the storage cost at the\nminers. In addition, SRB also decreases the bootstrapping cost, which allows\nfor new miners to easily join a sharded blockchain. In order to reduce storage,\ncoding-theoretic techniques are used in SRB. In order to decrease the amount of\ndata that is transferred to the new node joining a shard, the concept of exact\nrepair secure regenerating codes is used. The proposed blockchain protocol\nachieves lower storage than those that do not use coding, and achieves lower\nbootstrapping cost as compared to the different baselines.\n
Blockchain has made an impact on today's technology by revolutionizing the financial industry through utilization of cryptocurrencies using decentralized control. This has been followed by extending Blockchain to span several other industries and applications for its capabilities in verification. With the current trend of pursuing the decentralized Internet, many methods have been proposed to achieve decentralization considering different aspects of the current Internet model ranging from infrastructure and protocols to services and applications. This paper investigates Blockchain's capacities to provide a robust and secure decentralized model for Internet. The paper conducts a critical review on recent Blockchain-based methods capable for the decentralization of the future Internet. We identify and investigate two research aspects of Blockchain that provides high impact in realizing the decentralized Internet with respect to current Internet and Blockchain challenges while keeping various design in considerations. The first aspect is the consensus algorithms that are vital components for decentralization of the Blockchain. We identify three key consensus algorithms including PoP, Paxos, and PoAH that are more adequate for reaching consensus for such tremendous scale Blockchain-enabled architecture for Internet. The second aspect that we investigated is the compliance of Blockchain with various emerging Internet technologies and the impact of Blockchain on those technologies. Such emerging Internet technologies in combinations with Blockchain would help to overcome Blockchain's established flaws in a way to be more optimized, efficient and applicable for Internet decentralization.
Pablo G. Bringas, Iker Pastor-López, Giuseppe Psaila
Abstract Background BlockChain technology was invented to support bitcoin , currently the most popular virtual currency. Objectives The purpose of this paper is to investigate contemporary BlockChain platforms in financial services. Methods/Approach An unstructured literature review has been used. Results BlockChain in financial services is mostly associated with bitcoin exchange. However, this is a partial view of both BlockChain technology and its possible adoption for financial services: in fact, many BlockChain platforms are now available and many different financial services can be effectively supported by BlockChain platforms, even though they are not based on virtual-money exchange. Furthermore, people are attracted by the concept of smart contract , i.e., a contract that is automatically executed by computer technology, without human intervention. Conclusions The contribution of this paper is twofold: first of all, we introduce the four BlockChain platforms that are now most popular, discussing how they support the smart contract concept; second, we identify some typical categories of financial services, matching each of them with the platform that provides the best support for each category.
Roben Castagna Lunardi, Maher Alharby, Henry C. Nunes, Avelino F. Zorzo · 6 authors
Blockchain technology has been applied to various applications (e.g., smart buildings and smart cities) that typically run in an environment of smart devices, known as Internet-of-Things (IoT). To support these applications, different blockchain architectures, data structures and consensus algorithms have been proposed, tailored to IoT. One such proposal, appendable-block blockchain, is a promising blockchain framework for use in IoT environments. It provides a scalable data structure that allows parallel insertions between independent nodes. However, it has some limitations, in particular related to the possible eclipse attack by malicious gateways and the lack of consensus for transactions insertion. To solve these issues, we propose a new consensus mechanism for appendable-block blockchains, called context-based consensus. Using context-based consensus, information can be inserted in parallel across devices (called context) while ensuring that light-weight consensus is performed to guarantee that a transaction is well-formed and it is placed in the correct order. We implemented context-based consensus and show that using multiple contexts reduces latency and increases the throughput of transaction insertions when compared to consensus without contexts or using single transaction consensus.
Blockchain technologies have been rapidly enhanced in recent years. However, its scalability still has limitations in terms of throughput and broadcast delay as the network and the amount of transaction data increase. To improve scalability of blockchain networks, we propose a novel approach named PiChu that accelerates block propagation in blockchain networks by pipelining and verifying chunks of a block in parallel. Accelerating block propagation reduces the mining interval and chance of fork occurring, which in turn increases throughput. Our approach can be applied to the blockchain networks either directly or with a minor modification to the consensus. Through an extensive and large scale simulations, we validate that the proposed PiChu scheme significantly enhances the scalability of blockchain networks. For instance, a 64 MB block can be broadcasted in just 80 seconds in a blockchain network with a million nodes. The efficiency of PiChu broadcasting increases with bigger block sizes and a larger number of nodes in the network.
Christos Profentzas, Magnus Almgren, Olaf Landsiedel
With the rise of the Internet of Things (IoT), billions of devices ranging from simple sensors to smart-phones will participate in billions of micropayments. However, current centralized solutions are unable to handle a massive number of micropayments from untrusted devices. Blockchains are promising technologies suitable for solving some of these challenges. Particularly, permissionless blockchains such as Ethereum and Bitcoin have drawn the attention of the research community. However, the increasingly large-scale deployments of blockchain reveal some of their scalability limitations. Prominent proposals to scale the payment system include off-chain protocols such as payment channels. However, the leading proposals assume powerful nodes with an always-on connection and frequent synchronization. These assumptions require in practice significant communication, memory, and computation capacity, whereas IoT devices face substantial constraints in these areas. Existing approaches also do not capture the logic and process of IoT, where applications need to process locally collected sensor data to allow for full use of IoT micro-payments. In this paper, we present TinyEVM, a novel system to generate and execute off-chain smart contracts based on sensor data. TinyEVM's goal is to enable IoT devices to perform micro-payments and, at the same time, address the device constraints. We investigate the trade-offs of executing smart contracts on low-power IoT devices using TinyEVM. We test our system with 7,000 publicly verified smart contracts, where TinyEVM achieves to deploy 93% of them without any modification. Finally, we evaluate the execution of off-chain smart contracts in terms of run-time performance, energy, and memory requirements on IoT devices. Notably, we find that low-power devices can deploy a smart contract in 215 ms on average, and they can complete an off-chain payment in 584 ms on average.
A popular method in practice offloads computation and storage in blockchains by relying on committing only hashes of off-chain data into the blockchain. This mechanism is acknowledged to be vulnerable to a stalling attack: the blocks corresponding to the committed hashes may be unavailable at any honest node. The straightforward solution of broadcasting all blocks to the entire network sidesteps this data availability attack, but it is not scalable. In this paper, we propose ACeD, a scalable solution to this data availability problem with $O(1)$ communication efficiency, the first to the best of our knowledge. The key innovation is a new protocol that requires each of the $N$ nodes to receive only $O(1/N)$ of the block, such that the data is guaranteed to be available in a distributed manner in the network. Our solution creatively integrates coding-theoretic designs inside of Merkle tree commitments to guarantee efficient and tamper-proof reconstruction; this solution is distinct from Asynchronous Verifiable Information Dispersal (in guaranteeing efficient proofs of malformed coding) and Coded Merkle Tree (which only provides guarantees for random corruption as opposed to our guarantees for worst-case corruption). We implement ACeD with full functionality in 6000 lines of Rust code, integrate the functionality as a smart contract into Ethereum via a high-performance implementation demonstrating up to 10,000 transactions per second in throughput and 6000x reduction in gas cost on the Ethereum testnet Kovan.