To enable roaming of users, the cellular ecosystem integrates many entities and procedures, including specific infrastructure to connect Mobile Network Operators (MNOs), business partnerships or the use of third-party Data Clearing Houses (DCHs) for billing. Many of these rely on specifications rooted in dated and arcane practices, involving long waiting periods for financial clearing, complex billing models, and disparate mechanisms for dealing with inter-MNO disputes. In this paper, we propose a novel solution, DICE (Dynamic Interconnections for the Cellular Ecosystem), aimed at facilitating dynamic collaboration between MNOs, and sustain fluid interconnection models between the end-users and MNOs. DICE uses distributed ledger technology (DLT) to enable MNOs to interact directly, and offer customizable services to their users through the use of crypto-currencies. We leverage real-world data from a major operational MNO in Europe to support our claims, and to extract the requirements for the DICE system. We introduce the DICE protocol, and discuss real-world implementation considerations.
Recently, blockchain has elicited escalating attention from academia to industry. However, blockchain is still in its initial stage, and remains a great number of non-trivial problems to be delved before being used as a generic platform. The most intractable one is the scalability problem. The deep reinforcement learning empowered adaptivity can help the blockchain network break through the bottleneck. In this paper, we study a deep reinforcement learning empowered adaptivity approach for future blockchain networks, so as to improve the scalability and meet the requirements of different users. Specifically, rather than using one consensus protocol as the best fit one, the blockchain networks launch different consensus protocols, based on users’ quality of service (QoS) requirements. To this end, we quantify four consensus protocols. Additionally, the blockchain networks are heavily hampered by the limited computation and bandwidth resources. We also dynamically allocate computation and bandwidth resources to the blockchain networks. Then we formulate these thress items, i.e., the selection of consensus protocols, computation resource, and network bandwidth resource, as a joint optimization problem. A deep reinforcement learning approach is used to solve this problem. Simulation results are presented to show the effectiveness of our proposed scheme.
Ben Weintraub, Cristina Nita-Rotaru, Stefanie Roos
Payment channel networks (PCN) enable scalable blockchain transactions without fundamentally changing the underlying distributed ledger algorithm. However, routing a payment via multiple channels in a PCN requires locking collateral for potentially long periods of time. Adversaries can abuse this mechanism to conduct denial-of-service attacks. Previous work focused on source routing, which is unlikely to remain a viable routing approach as these networks grow. In this work, we examine the effectiveness of attacks in PCNs that use routing algorithms based on local knowledge, where compromised intermediate nodes can delay or drop transactions to create denial-of-service. We focus on SpeedyMurmurs as a representative of such protocols. We identify two attacker node selection strategies; one based on the position in the routing tree, and the other on between-ness centrality. Our simulation-driven study shows that while they are both effective, the centrality-based attack approaches near-optimal effectiveness. We also show that the attacks are ineffective in less centralized networks and discuss incentives for the participants in PCNs to create less centralized topologies through the payment channels they establish among themselves.
Muhammad Baqer Mollah, Jun Zhao, Dusit Niyato, Yong Liang Guan · 8 authors
Internet of Vehicles (IoV) is an emerging concept that is believed to help realize the vision of intelligent transportation systems (ITSs). IoV has become an important research area of impactful applications in recent years due to the rapid advancements in vehicular technologies, high throughput satellite communication, the Internet of Things, and cyber-physical systems. IoV enables the integration of smart vehicles with the Internet and system components attributing to their environments, such as public infrastructures, sensors, computing nodes, pedestrians, and other vehicles. By allowing the development of a common information exchange platform between vehicles and heterogeneous vehicular networks, this integration aims to create a better environment and public space for the people as well as to enhance safety for all road users. Being a participatory data exchange and storage, the underlying information exchange platform of IoV needs to be secure, transparent, and immutable in order to achieve the intended objectives of ITS. In this connection, the adoption of blockchain as a system platform for supporting the information exchange needs of IoV has been explored. Due to their decentralized and immutable nature, IoV applications enabled by blockchain are believed to have a number of desirable properties, such as decentralization, security, transparency, immutability, and automation. In this article, we present a contemporary survey on the latest advancement in blockchain for IoV. Particularly, we highlight the different application scenarios of IoV after carefully reviewing the recent literature. We also investigate several key challenges where blockchain is applied in IoV. Furthermore, we present the future opportunities and explore further research directions of IoV as a key enabler of ITS.
Universal connectivity is still unavailable or expensive for half of the global population, despite being critical for social participation. The deployment of crowdsourced networking infrastructures creates an opportunity for local development, where anyone can deploy a new device. In such infrastructures connectivity offer can expand incrementally and be sustainable through investment and fees resulting from the demand and consumption of content and services, including Internet access, that compensate the cost of the underlying network. While routing coordinates network data flows, economic flows can be coordinated by smart contracts built over a local distributed ledger. We define crowdsourced networks, the concept, architecture, and implementation using a local Ethereum PoA blockchain with Solidity smart contracts that compensate the data traffic contribution and consumption recorded by a traffic monitoring system, on a wireless mesh network. The prototype software has been validated in a controlled mesh network environment. Functional tests show its ability to account and route economic flows with small resource consumption, and therefore confirms these networks can develop organically by the addition of consumer and provider participants to reach the typical scale of most wireless mesh access networks and deliver networking services that aim to be socially and economically sustainable.
There is a great interest in many approaches towards blockchain in providing a solution to record transactions in a decentralized way. However, there are some limitations when storing large files or documents on the blockchain. In order to meet the requirements of storing relatively large data, a decentralized storage medium is produced. IPFS is a distributed file system which is content-addressable. It works very similar to the blockchain network. There are some attempts which take advantage of the blockchain concept and IPFS to design new approaches. Unfortunately, there are some inefficiencies in sharing data using the combination of IPFS and blockchain. In this paper, we proposed a secure file sharing system that brings a distributed access control and group key management by the adoption of the IPFS proxy. The IPFS proxy which plays an important role in the design is adopted to take responsibility for the control policies. The combination of the IPFS server and the blockchain network with the adoption of the IPFS proxy make a secure file sharing system which the members on the system can create new groups or join different groups by their own choice. Although there is no access control mechanism in IPFS server and blockchain network, the secure file sharing system manages the access control policies. The members access files only belong to the group they authorized.
Dimitris Vyzovitis, Yusef Napora, Dirk McCormick, David Dias · 5 authors
Permissionless blockchain environments necessitate the use of a fast and\nattack-resilient message propagation protocol for Block and Transaction\nmessages to keep nodes synchronised and avoid forks. We present GossipSub, a\ngossip-based pubsub protocol, which, in contrast to past pubsub protocols,\nincorporates resilience against a wide spectrum of attacks.\n Firstly, GossipSub's mesh construction implements an eager push model keeps\nthe fan-out of the pubsub delivery low and balances excessive bandwidth\nconsumption and fast message propagation throughout the mesh. Secondly, through\ngossip dissemination, GossipSub realises a lazy-pull model to reach nodes\nfar-away or outside the mesh. Thirdly, through constant observation, nodes\nmaintain a score profile for the peers they are connected to, allowing them to\nchoose the most well-behaved nodes to include in the mesh. Finally, and most\nimportantly, a number of tailor-made mitigation strategies designed\nspecifically for these three components make GossipSub resilient against the\nmost challenging Sybil-based attacks. We test GossipSub in a testbed\nenvironment involving more than 5000 VM nodes deployed on AWS and show that it\nstays immune to all considered attacks. GossipSub is currently being integrated\nas the main messaging layer protocol in the Filecoin and the Ethereum 2.0\n(ETH2.0) blockchains.\n
This project aims to create a blockchain-based model that addresses key challenges in digital voting. The goal is to develop a secure and transparent system that eliminates common issues such as delays in result announcements, voter identity verification concerns, and security risks [1]. Voting is the backbone of any democracy, and ensuring its integrity is crucial. Traditional digital voting systems often face problems like fraud, manipulation, and lack of transparency. Blockchain technology, with its decentralized and tamper-proof nature, offers a promising solution. It functions as a distributed ledger that records transactions securely in a peer-to-peer network, making it nearly impossible to alter past data [2]. This technology brings several benefits to voting, including decentralization, security, transparency, immutability, and voter anonymity [3]. A major highlight of this project is the integration of blockchain with smart contracts, which adds an extra layer of security and automation to the voting process [4]. The system is designed to work on the Ethereum blockchain, using smart contracts written in Solidity and accessed through blockchain wallets [5]. By eliminating the need for a central authority to oversee elections, this approach ensures a fair and transparent voting process where every vote is securely recorded and cannot be tampered with [6]. In essence, this project reimagines digital voting by leveraging blockchain’s strengths, making elections more secure, efficient, and trustworthy.
Open access
3 source records
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
In Bitcoin and Ethereum, nodes require large storage capacity to maintain all the blockchain data, such as transactions, UTXOs, and account states. As of May 2020, the storage size of the Bitcoin blockchain has expanded to 270 GB, and it will continue to increase. This storage requirement is a major hurdle to becoming a block proposer or validator. Although many studies have attempted to reduce the storage size, in the proposed methods, a node cannot keep all blocks or cannot generate a block. We propose an architecture called Trail that allows nodes to hold all blocks in a small storage and to generate and validate blocks and transactions. Trail does not depend on a consensus algorithm or fork choice rule. In this architecture, a client who issues transactions has the data to prove its own balances and can generate a transaction containing the proof of balances. The nodes in Trail do not store transactions, UTXOs and account balances: they keep only blocks. The blocksize is approximately 8 KB, which is 100 times smaller than that of Bitcoin. Further, the block size is constant regardless of the number of accounts and the number of transactions. Compared to traditional blockchains, clients who issue transactions must store additional data. However, we show that proper data archiving can keep the account device storage size small. Trail allows more users to be block proposers and validators and improves the decentralization of the blockchain.
This paper presents an architecture, based on Distributed Ledger Technologies (DLTs) and Decentralized File Storage (DFS) systems, to support the use of Personal Information Management Systems (PIMS). DLT and DFS are used to manage data sensed by mobile users equipped with devices with sensing capability. DLTs guarantee the immutability, traceability and verifiability of references to personal data, that are stored in DFS. In fact, the inclusion of data digests in the DLT makes it possible to obtain an unalterable reference and a tamper-proof log, while remaining compliant with the regulations on personal data, i.e. GDPR. We provide an experimental evaluation on the feasibility of the use of DFS. Three different scenarios have been studied: i) a proprietary IPFS approach with a dedicated node interfacing with the data producers, ii) a public IPFS service and iii) Sia Skynet. Results show that through proper configuration of the system infrastructure, it is viable to build a decentralized Personal Data Storage (PDS).
Dimitris Chatzopoulos, Sujit Gujar, Boi Faltings, Pan Hui
Advances in mobile computing have paved the way for new types of distributed applications that can be executed solely by mobile devices on device-to-device (D2D) ecosystems (e.g., crowdsensing). More sophisticated applications, like cryptocurrencies, need distributed ledgers to function. Distributed ledgers, such as blockchains and directed acyclic graphs (DAGs), employ consensus protocols to add data in the form of blocks. However such protocols are designed for resourceful devices that are interconnected via the Internet. Moreover, existing distributed ledgers are not deployable to D2D ecosystems since their storage needs are continuously increasing. In this work, we introduce Mneme, a DAG-based distributed ledger that can be maintained solely by mobile devices and operates via two consensus protocols: Proof-of-Context (PoC) and Proof-of-Equivalence (PoE). PoC employs users' context to add data on Mneme. PoE is executed periodically to summarize data and produce equivalent blocks that require less storage. We analyze the security of Mneme and justify the ability of PoC and PoE to guarantee the characteristics of distributed ledgers: persistence and liveness. Furthermore, we analyze potential attacks from malicious users and prove that the probability of a successful attack is inversely proportional to the square of the number of mobile users who maintain Mneme.
Mohammad Saeid Safaei, Shamsollah Ghanbari, Zhanat Umarova, Zhalgasbek Iztayev
IoT is one of the most important and profitable projects proposed by Kevin Ashton since 1999. One of the most critical issues in maintaining communication between things and protecting the data is the security issue of IoT. So far, different strategies have been made to maintain safe security. In this paper, we provide a Five-Layers model by adding two security layers based on BlockChain. We show that blockchain smart contracts are a solution to enhance IoT security and prevent infiltration into the network.
The interblockchain communication protocol (IBC) is an end-to-end, connection-oriented, stateful protocol for reliable, ordered, and authenticated communication between modules on separate distributed ledgers. IBC is designed for interoperation between heterogenous ledgers arranged in an unknown, dynamic topology, operating with varied consensus algorithms and state machines. The protocol realises this by specifying the sufficient set of data structures, abstractions, and semantics of a communication protocol which once implemented by participating ledgers will allow them to safely communicate. IBC is payload-agnostic and provides a cross-ledger asynchronous communication primitive which can be used as a constituent building block by a wide variety of applications.
A key performance metric in blockchains is the latency between when a transaction is broadcast and when it is confirmed (the so-called, confirmation latency). While improvements in consensus techniques can lead to lower confirmation latency, a fundamental lower bound on confirmation latency is the propagation latency of messages through the underlying peer-to-peer (p2p) network (inBitcoin, the propagation latency is several tens of seconds). The de facto p2p protocol used by Bitcoin and other blockchains is based on random connectivity: each node connects to a random subset of nodes. The induced p2p network topology can be highly suboptimal since it neglects geographical distance, differences in bandwidth, hash-power and computational abilities across peers. We present Perigee, a decentralized algorithm that automatically learns an efficient p2p topology tuned to the aforementioned network heterogeneities, purely based on peers' interactions with their neighbors. Motivated by the literature on the multi-armed bandit problem, Perigee optimally balances the tradeoff between retaining connections to known well-connected neighbors, and exploring new connections to previously-unseen neighbors. Experimental evaluations show that Perigee reduces the latency to broadcast by $33\%$. Lastly Perigee is simple, computationally lightweight, adversary-resistant, and compatible with the selfish interests of peers, making it an attractive p2p protocol for blockchains.
The Bitcoin Lightning network is a mechanism to enable fast and inexpensive off-chain Bitcoin transactions using peer-to-peer (P2P) channels between nodes that can also be composed into a routing path. Although the resulting possible channel graphs are well-studied, there is no empirical data on the network's reliability in terms of being able to successfully route payments at a given moment in time. In this paper we address this gap and investigate two forms of availability that are a necessary ingredient to achieve such reliability. We first study the Lightning network's ability to route payments of various sizes to nearly every participating node, over most available channels. We establish an inverse relationship between payment volume and success rate and show that at best only about a third of destination nodes can be successfully reached. The routing is hampered by a number of possible errors, both transient and permanent. We then study the availability of nodes in the network longitudinally and determine how long-lived they are. Churn in the network is actually low, and a considerable number of nodes are hosted on cloud providers. By testing node liveness, we find that the propagated network information is relatively often stale, however, both for IP addresses and Tor onion addresses. We provide recommendations how the Lightning network can be improved, including considerations which trade-offs between privacy and decentralization on the one hand and reliability on the other hand should at least be reconsidered by the community developing the Lightning network.
Johannes Sedlmeir, Hans Ulrich Buhl, Gilbert Fridgen, Robert Keller
Abstract When talking about blockchain technology in academia, business, and society, frequently generalizations are still heared about its – supposedly inherent – enormous energy consumption. This perception inevitably raises concerns about the further adoption of blockchain technology, a fact that inhibits rapid uptake of what is widely considered to be a groundbreaking and disruptive innovation. However, blockchain technology is far from homogeneous, meaning that blanket statements about its energy consumption should be reviewed with care. The article is meant to bring clarity to the topic in a holistic fashion, looking beyond claims regarding the energy consumption of Bitcoin, which have, so far, dominated the discussion.
We propose a fully distributed system architecture and a scalable self-organized sharding scheme for the Internet-of-Things (IoT) blockchains that can guarantee system security without reducing its throughput. In the system, the IoT devices are supported by the set of blockchain peers that gather, process, verify, and store the blocks of IoT transaction records. To support communications among peers, the system is realized in the mobile-edge computing (MEC) network. We design a new consensus mechanism in which each peer votes on the outputs of each block task in its shard. The peer's voting power is computed from its reputation, i.e., trustworthiness in the system. By adopting a reputation-based coalitional game model, we formulate a novel self-organized shard formation algorithm in which each peer acts as a rational player aiming to maximize both its payoff and the coalitional reputation. We prove that the algorithm converges to the reputation-based stable shard structure, i.e., a structure that maximizes the payoff and coalitional reputation of each peer without negatively affecting other peers. The algorithm shows a superior performance in terms of system security and throughput when compared to state-of-the-art sharding schemes and reputation-based blockchains.
Sergey Smetanin, Aleksandr Ometov, Mikhail Komarov, Pavel Mašek · 5 authors
The present increase of attention toward blockchain-based systems is currently reaching a tipping point with the corporate focus shifting from exploring the technology potential to creating Distributed Ledger Technology (DLT)-based systems. In light of a significant number of already existing blockchain applications driven by the Internet of Things (IoT) evolution, the developers are still facing a lack of tools and instruments for appropriate and efficient performance evaluation and behavior observation of different blockchain architectures. This paper aims at providing a systematic review of current blockchain evaluation approaches and at identifying the corresponding utilization challenges and limitations. First, we outline the main metrics related to the blockchain evaluation. Second, we propose the blockchain modeling and analysis classification based on the critical literature review. Third, we extend the review with publicly accessible industrial tools. Next, we analyze the selected results for each of the proposed classes and outline the corresponding limitations. Finally, we identify current challenges of the blockchain analysis from the system evaluation perspective, as well as provide future perspectives.
With the recent considerable developments in the Internet of Things (IoT), billions of resource-constrained devices are interconnected through the internet. Monitoring this huge number of IoT devices that are heterogeneous in terms of underlying communication protocols and data format is challenging. The majority of existing IoT device monitoring solutions heavily rely on centralized architectures. Since using centralized architectures comes at the expense of trusting an authority, it has several inherent drawbacks, including vulnerability to security attacks, lack of data privacy, and unauthorized data manipulation. Hence, a new decentralized approach is crucial to remedy these drawbacks. One of the most promising technologies which is widely used to provide decentralization is blockchain. Additionally, to ease the burden of communication overhead and computational power on resource-constrained IoT devices, fog computing can be exploited to decrease communication latency and provide better network scalability. In this paper, we propose a scalable blockchain-based architecture for monitoring IoT devices using fog computing. To demonstrate the feasibility and usability of the proposed solution, we have implemented a proof-of-concept prototype, leveraging Ethereum smart contracts. Finally, a comprehensive evaluation is conducted. The evaluation results indicate that the proposed solution is significantly scalable and compatible with resource-constrained IoT devices.
With the recent considerable developments in the Internet of Things (IoT),\nbillions of resource-constrained devices are interconnected through the\ninternet. Monitoring this huge number of IoT devices that are heterogeneous in\nterms of underlying communication protocols and data format is challenging. The\nmajority of existing IoT device monitoring solutions heavily rely on\ncentralized architectures. Since using centralized architectures comes at the\nexpense of trusting an authority, it has several inherent drawbacks, including\nvulnerability to security attacks, lack of data privacy, and unauthorized data\nmanipulation. Hence, a new decentralized approach is crucial to remedy these\ndrawbacks. One of the most promising technologies which is widely used to\nprovide decentralization is blockchain. Additionally, to ease the burden of\ncommunication overhead and computational power on resource-constrained IoT\ndevices, fog computing can be exploited to decrease communication latency and\nprovide better network scalability.\n In this paper, we propose a scalable blockchain-based architecture for\nmonitoring IoT devices using fog computing. To demonstrate the feasibility and\nusability of the proposed solution, we have implemented a proof-of-concept\nprototype, leveraging Ethereum smart contracts. Finally, a comprehensive\nevaluation is conducted. The evaluation results indicate that the proposed\nsolution is significantly scalable and compatible with resource-constrained IoT\ndevices.\n
In legacy blockchain based systems, each involved node has to store a complete blockchain to ensure the system security without any central authoritative controller. However, it is usually impossible for a wireless IoT node to store a complete blockchain, especially for those simple sensor nodes without sufficient storage and computing resources. In this paper, we propose a block assignment scheme for blockchain based wireless IoT systems with aim to tackle the blockchain storage problem. Specifically, we propose to maintain a complete blockchain by a set of IoT nodes in a collaborative way on the premise of ensuring that each node can check every transaction. On the other hand, we should save the storage space of IoT nodes to the greatest extent for saving more blocks so as to maximize the lifetime of IoT nodes. We formulate this optimal block assignment problem as a 0-1 mixed integer-programming problem. We propose to incorporate Chaotic optimized algorithm into Genetic algorithm to provide an efficient near-optimal solution. Compared with the brute-force and conventional Genetic algorithms, our proposed algorithm can achieve the minimum storage occupancy to store blocks. Meanwhile, the proposed algorithm has the lowest computational complexity.
Since the expansion of the Internet of Things (IoT), connected devices became smart and autonomous. Their exponentially increasing number and their use in many application domains result in a huge potential of cybersecurity threats. Taking into account the evolution of the IoT, security and interoperability are the main challenges, to ensure the reliability of the information. The blockchain technology provides a new approach to handle the trust in a decentralized network. However, current blockchain implementations cannot be used in the IoT domain because of their huge need for computing power and storage utilization. This paper provides a lightweight distributed ledger protocol dedicated to the IoT application, reducing the computing power and storage utilization, handling the scalability and ensuring the reliability of the information.
Abstract: Because of its accessibility and ease of use, cloud storage has become the most widely used type of storage on the market in recent years. However, the privacy and data security of cloud storage are at risk. The protection of data security and privacy is the main topic of this essay. We suggest a blockchain-based decentralised storage system. Since blockchain is a distributed peer-to-peer system, any processing node connected to the internet can join and build peers' networks, maximising resource usage. Blockchain protects data security. The user's file is encrypted and shared among a number of network peers in the proposed system utilising the IPFS (Interplanetary File System) protocol. Hashes are generated by IPFS. The path of the file is indicated by the hash value, which is kept on the blockchain. This project is focused on decentralised secure data storage, high data availability, and effective storage resource usage.
The formation of IT companies and even of entire new technological ecosystems depends heavily on external financing. Consequently, the IS community has intensely studied various financing sources such as venture capital, initial public offerings or debt. Blockchain technology has led to the emergence of a system of decentralized finance (DeFi) which includes decentralized versions of equity and debt financing. In particular, equity-like fundraisings referred to as initial coin offerings (ICO) have received serious traction. In this paper, we investigate the role of user-generated content (UGC) for ICO success. Specifically, we leverage signaling theory to analyze how the activity on blogs and discussion forums is related to the amount of capital raised and the valuation in ICOs. We analyze data of 216 ICOs and provide first results indicating the importance of discussion forum activity for ICO success. Furthermore, we find that blogs seem less relevant than in traditional finance.