A network composed of lightweight devices such as IoT has problems due to limited resources such as lack of storage space and low computing performance. These issues pose significant challenges in the application of robust security technologies, which reduces network security performance. The blockchain with strong security is a suitable technology to solve IoT problems with weak security. As a result, various research is being carried out to increase security, lightness, and efficiency of the IoT network by applying blockchain to IoT. This paper introduces the trend of research to apply blockchain to IoT.
Cryptocurrencies are based on cryptography-based asset disposals broadcasted peer-to-peer to be validated decentrally according to consensus mechanisms in compliance with consented protocols. Protocol development is associated with risks, and there are conflicts of interests. Collusion involving protocol developers may increase such risks. This paper explores liability for collusion in cryptocurrency protocol development. It is found that liability gives some, but not sufficient, protection against harmful collusion.
Bitcoin is a digital currency proposed by a developer hided under the pseudonym Satoshi \nNakamoto in 2009, and it is relied on a peer-to-peer payment system created as an open \nsource software. It is relied on blockchain a distributed and democratically-sustained public \nregister of the transactions. Bitcoin, as well as other digital currencies, has a lower \ntransaction cost and greater security and scalability than fiat money and no need of a central \nbank. However, in the last years several researchers have relived environmental issues \nrelated to the use of this money. On the contrary, the relate technology of blockchain is \nrecognizing as a significant tool contributing to create a more sustainable world. In this \ncontext, the purpose of this paper is to describe and evaluate the sustainability of the Bitcoin \ncurrency and the blockchain technology considering the environmental and social impacts \ndue to energy consumption, market diffusion compared to fiat currency. Blockchain can \nreduce and accelerate bureaucracy processes as well as incentivize environmentally friendly \nbehaviour. Under these perspectives, blockchain may show the full applicability of \nsustainability in the economic, environmental and social sectors.
Raheel Ahmed Memon, Jianping Li, Muhammad Irshad Nazeer, Ahmad Neyaz Khan · 5 authors
Integration of blockchain and Internet of Things (IoT) to build a secure, trusted and robust communication technology is currently of great interest for research communities and industries. But challenge is to identify the appropriate position of blockchain in current settings of IoT with minimal consequences. In this article we propose a blockchain-based DualFog-IoT architecture with three configuration filter of incoming requests at access level, namely: Real Time, Non-Real Time, and Delay Tolerant Blockchain applications. The DualFog-IoT segregate the Fog layer into two: Fog Cloud Cluster and Fog Mining Cluster. Fog Cloud Cluster and the main cloud datacenter work in a tandem similar to existing IoT architecture for real-time and non-real-time application requests, while the additional Fog Mining Cluster is dedicated to deal with only Delay Tolerant Blockchain application requests. The proposed DualFog-IoT is compared with existing centralized datacenter based IoT architecture. Along with the inherited features of blockchain, the proposed model decreases system drop rate, and further offload the cloud datacenter with minimal upgradation in existing IoT ecosystem. The reduced computing load from cloud datacenter doesn't only help in saving the capital and operational expenses, but it is also a huge contribution for saving energy resources and minimizing carbon emission in environment. Furthermore, the proposed DualFog-IoT is also being analyzed for optimization of computing resources at cloud level, the results presented shows the feasibility of proposed architecture under various ratios of incoming RT and NRT requests. However, the integration of blockchain has its footprints in terms of latent response for delay tolerant blockchain applications, but real-time and non-real-time requests are gracefully satisfying the service level agreement.
Blockchain technologies have recently come to the forefront of the scientific and industrial communities. This is due to their practical capabilities in solving many issues in various industrial domains. Issues like securely sharing transactional data, establishing efficient supply chain processes, and enhancing transparency are some examples. Blockchain offers an effective way to tackle these issues using distributed, shared, secure, and permissioned transactional ledgers. The employment of blockchain technologies and the possibility of applying them in different situations enables many industrial applications through increased efficiency and security; enhanced traceability and transparency and reduced costs. In this paper, different industrial application domains where the use of blockchain technologies have been proposed are surveyed.
Bitcoin is a top-ranked cryptocurrency that has experienced huge growth and survived numerous attacks. The protocols making up Bitcoin must therefore accommodate the growth of the network and ensure security. However, Bitcoin’s transaction dissemination protocol has mostly evaded optimization. This protocol is based on flooding and though it is secure and fault-tolerant, it is also highly inefficient. Specifically, our measurements indicate that 43% of the traffic generated by transaction dissemination in the Bitcoin network is redundant. In this paper we introduce a new transaction dissemination protocol called Erlay. Erlay is a hybrid protocol that combines limited flooding with intermittent reconciliation. We evaluated Erlay in simulation and by implementing and deploying it at scale. Compared to Bitcoin’s current protocols, Erlay reduces the bandwidth used to announce transactions by 84% without significantly affecting privacy or propagation speed. In addition, Erlay retains the existing Bitcoin security guarantees and is more scalable relative to the number of nodes in the network and their connectivity. Erlay is currently being investigated by the Bitcoin community for future use with the Bitcoin protocol.
Online content delivery has witnessed dramatic growth recently with traffic consuming over half of today’s Internet bandwidth. This escalating demand has motivated content publishers to move outside the traditional solutions of infrastructure-based content delivery networks (CDNs). Instead, many are employing peer-to-peer data transfers to reduce the service cost and avoid bandwidth over-provision to handle peak demands. Unfortunately, the open access work model of this paradigm, which allows anyone to join, introduces several design challenges related to security, efficiency, and peer availability. In this dissertation, we introduce CacheCash, a cryptocurrency-based decentralized content distribution network designed to address these challenges. CacheCash bypasses the centralized approach of CDN companies for one in which end users organically set up new caches in exchange for cryptocurrency tokens. Thus, it enables publishers to hire caches on an as-needed basis, without constraining these parties with long-term business commitments. To address the challenges encountered as the system evolved, we propose a number of protocols and techniques that represent basic building blocks of CacheCash’s design. First, motivated by the observation that conventional security assessment tools do not suit cryptocurrency-based systems, we propose ABC, a threat modeling framework capable of identifying attacker collusion and the new threat vectors that cryptocurrencies introduce. Second, we propose CAPnet, a defense mechanism against cache accounting attacks (i.e., a client pretends to be served allowing a colluding cache to collect rewards without doing any work). CAPnet features a bandwidth expenditure puzzle that clients must solve over the content before caches are given credit, which bounds the effectiveness of this collusion case. Third, to make it feasible to reward caches per data chunk served, we introduce MicroCash, a decentralized probabilistic micropayment scheme that reduces the overhead of processing these small payments. MicroCash implements several novel ideas that make micropayments more suitable for delay-sensitive applications, such as online content delivery. CacheCash combines the previous techniques to produce a novel service-payment exchange protocol that secures the content distribution process. This protocol utilizes gradual content disclosure and partial payment collection to encourage the honest collaborative work between participants. We present a detailed game theoretic analysis showing how to exploit rational financial incentives to address several security threats. This is in addition to various performance optimization mechanisms that promote system efficiency and scalability. Lastly, we evaluate system performance and show that modest machines can serve/retrieve content at a high bitrate with minimal overhead.
Open access
Caching and Content Delivery
Peer-to-Peer Network Technologies
Advanced Steganography and Watermarking Techniques
There are some registry agreements that may be appropriate for the Internet of Things (IoT), including Bitcoin, Hyperledger Fabric and IOTA. This article presents quickly and examines them in terms of the progress of Internet applications. Block-dependent IoT applications can consolidate the chain's rationale (smart contracts) and front-end, portable or front-end web applications. We present three possible designs for BC IoT front-end applications. They vary depending on the Bitcoin block chain customer (neighborhood gadget, remote server) and the key location needed to manage active exchanges. The vital requirements of these projects, which use Bitcoin to organize constructive exchanges, are the volumes of information, the area and time of the complete block and block block, and the entry of the Bitcoin store. The implications of these surveys show that it is unlikely that a full Bitcoin distributor will continue to operate reliably with a mandatory IoT gadget. Then, designing with remote Bitcoin customers is, in all respects, a suitable methodology in which there are two minor alternatives and vary in key storage / management. Similarly, we recommend using the design with a unique match between the IoT gadget and the remote blockchain client to reduce system activity and improve security. We hope you also have the ability to operate with versatile verses with low control and low productivity. Our review eliminates the contradictions between synthesis methodologies, but the final choice for a particular registration agreement and the original technique completely depends on the proposed use case.
The goal of this research is to estimate the data propagation time on the Bitcoin network. Using network coordinates, we estimate the communication latency between computers. Such latency estimation contributes future optimization of data propagation. In this research, we report an experiment on computing the network coordinates. In the current Bitcoin network, it is very difficult to acquire internode delay because the network topology is not available. In this study, we calculate the delay based on our topology estimation and describe the effectiveness of the network coordinates using various topology estimation parameters.
Chao Qiu, Haipeng Yao, F. Richard Yu, Chunxiao Jiang · 5 authors
Recently, the emergence of blockchain has stirred great interests in the field of Internet of Things (IoT). However, numerous non-trivial problems in the current blockchain system prevent it from being used as a generic platform for large-scale services and applications in IoT. One notable drawback is the scalability problem. Lots of projects and researches have been done to solve this problem. Nevertheless, they do not consider different users' conditions, only using a single consensus protocol as the best fit one, as well as the IoT system is heavily constrained by computing and networking resources. In this article, we study a permissioned blockchain-based IoT architecture. In order to improve the scalability of the blockchain system and meet the needs of different users, we propose a service-oriented permissioned blockchain, where different consensus protocols are launched according to users' quality of service (QoS) requirements. Specially, we quantify a few popular consensus protocols. Additionally, we select block producers, which need a great number of computation resources, as well as dynamically allocate network bandwidth to the blockchain system. We formulate consensus protocols selection, block producers selection, and network bandwidth allocation as a joint optimization problem. We then use a dueling deep reinforcement learning approach to solve the problem. Simulation results demonstrate the effectiveness of our proposed scheme.
The old mantra of decentralizing the Internet is coming again with fanfare, this time around the blockchain technology hype. We have already seen a technology supposed to change the nature of the Internet: peer-to-peer. The reality is that peer-to-peer naming systems failed, peer-to-peer social networks failed, and yes, peer-to-peer storage failed as well. In this paper, we will review the research on distributed systems in the last few years to identify the limits of open peer-to-peer networks. We will address issues like system complexity, security and frailty, instability and performance. We will show how many of the aforementioned problems also apply to the recent breed of permissionless blockchain networks. The applicability of such systems to mature industrial applications is undermined by the same properties that make them so interesting for a libertarian audience: namely, their openness, their pseudo-anonymity and their unregulated cryptocurrencies. As such, we argue that permissionless blockchain networks are unsuitable to be the substrate for a decentralized Internet. Yet, there is still hope for more decentralization, albeit in a form somewhat limited with respect to the libertarian view of decentralized Internet: in cooperation rather than in competition with the superpowerful datacenters that dominate the world today. This is derived from the recent surge in interest in byzantine fault tolerance and permissioned blockchains, which opens the door to a world where use of trusted third parties is not the only way to arbitrate an ensemble of entities. The ability of establish trust through permissioned blockchains enables to move the control from the datacenters to the edge, truly realizing the promises of edge-centric computing.
This work presents ContractChecker, a Blockchain-based security protocol for verifying the storage consistency between the mutually distrusting cloud provider and clients. Unlike existing protocols, the ContractChecker uniquely delegates log auditing to the Blockchain, and has the advantages in reducing client cost and lowering requirements on client availability, lending itself to modern scenarios with mobile and web clients. The ContractChecker collects the logs from both clients and the cloud server, and verifies the consistency by cross-checking the logs. By this means, it does not only detects the attacks from malicious clients and server forging their logs, but also is able to mitigate those attacks and recover the system from them. In addition, we design new attacks against ContractChecker exploiting various limits in real Blockchain systems (e.g., write unavailability, Blockchain forks, contract race conditions). We analyze and harden the security of ContractChecker protocols against the proposed new attacks. For evaluating the cost, we build a functional prototype of the ContractChecker on Ethereum/Solidity. By experiments on private and public Ethereum testnets, we extensively evaluate the cost of the ContractChecker in comparison with that of existing client-based log auditing works. The result shows the ContractChecker can scale to hundreds of clients and save client costs by more than one order of magnitude.
Jordi Paillissé, Jan Manrique, Guillem Bonet, Alberto Rodríguez-Natal · 6 authors
Inter-domain routing security is of critical importance to the Internet since it prevents unwanted traffic redirections. The current system is based on a Public Key Infrastructure (PKI), a centralized repository of digital certificates. However, the inherent centralization of such design creates tensions between its participants and hinders its deployment. In addition, some technical drawbacks of PKIs delay widespread adoption. In this paper we present IPchain, a blockchain to store the allocations and delegations of IP addresses. IPchain leverages blockchains' properties to decentralize trust among its participants, with the final goal of providing flexible trust models that adapt better to the ever-changing geopolitical landscape. Moreover, we argue that Proof of Stake is a suitable consensus algorithm for IPchain due to the unique incentive structure of this use-case, and that blockchains offer relevant technical advantages when compared to existing systems, such as simplified management. In order to show its feasibility and suitability, we have implemented and evaluated IPchain's performance and scalability storing around 350k IP prefixes in a 2.5 GB chain.
Georgia Avarikioti, Lukas Käppeli, Yuyi Wang, Roger Wattenhofer
We prove Bitcoin is secure under temporary dishonest majority. We assume the adversary can corrupt a specific fraction of parties and also introduce crash failures, i.e., some honest participants are offline during the execution of the protocol. We demand a majority of honest online participants on expectation. We explore three different models and present the requirements for proving Bitcoin's security in all of them: we first examine a synchronous model, then extend to a bounded delay model and last we consider a synchronous model that allows message losses.
Wenli Yang, Erfan Aghasian, Saurabh Garg, David Herbert · 6 authors
The emergence of Internet protocol suites and packet-switching technologies tends to the considerations of security, privacy, scalability, and reliability in layered Internet service architectures. The existing service systems allow us to access big data, but few studies focus on the fundamental security and stability in these systems, especially when they involve large-scale networks with overloaded private information. In this paper, we explored the blockchain-based mechanism that aims to improve the critical features of traditional Internet services, including autonomous and decentralized processing, smart contractual enforcement of goals, and traceable trustworthiness in tamper-proof transactions. Furthermore, we provide a comprehensive review to conceptualize the blockchain-based framework to develop the decentralized protocols for the extensive number of Internet services. This comprehensive survey aims to address blockchain integration to secure Internet services and identify the critical requirements of developing a decentralized trustworthy Internet service. Additionally, we present a case study of the blockchain-based Internet of Things (IoT) for neuro-informatics to illustrate the potential applications of blockchain architectures. Finally, we summarize the trends and challenges of blockchain architectures that benefit a multitude of disciplines across all the Internet service fields of interest.
Jan 1, 2019·Proceedings of the ... Annual Hawaii International Conference on System Sciences/Proceedings of the Annual Hawaii International Conference on System Sciences
A.K.M. Najmul Islam, Matti Mäntymäki, Marja Turunen
This paper investigates the focal actors and their heterogeneity in blockchain splits. Disagreements in blockchain communities often lead to splits in the blockchain and the community. For example, disagreements within the Bitcoin community on increasing the block size led to the blockchain split and creation of Bitcoin Cash. We build on actor-network theory to investigate blockchain split as a translation process, and employ case study methodology to examine Bitcoin splits. We identify several human actors, such as miners, developers, merchants, and investors, as well as non-human actors including ideologies, exchanges and computer programs involved in Bitcoin splits. Our results show that actor heterogeneity, that is, the complex constellation of diverse actors, plays a key role in blockchain splits. We further describe how the human and non-human actors’ fluid moves into micro and macro positions in the network affect the development of the split. We also discuss the role of these actors and their engagement in forming micro and macro agencies in blockchain splits. Our study adds to the understanding of actor behavior and network dynamics in decentralized information systems such as blockchain and open source software.
With the popularity of Bitcoin, there is a greater demand for the scalability of the Bitcoin blockchain, which is susceptible to the efficiency of block propagation. In the Bitcoin blockchain, efficient block propagation approach can reduce the computing power and the risk of forks. Meanwhile, larger blocks help to improve the throughput of transactions. Thus, the block propagation is a major issue of the scalability of the Bitcoin network. This paper introduces a method to reduce the required bandwidth of block propagation with erasure coding. To begin with, the network nodes are classified into several clusters. When a node wants to propagate a block, the node does not need to propagate the whole information of the block. Instead, the node can only transmit the transaction IDs and the coded information to each cluster. The simulation shows that the proposed method can significantly ease the network traffic among these clusters.
Open access
Blockchain Technology Applications and Security
Caching and Content Delivery
Advanced Steganography and Watermarking Techniques