Peiyun Zhang, MengChu Zhou, Chenxi Li, Abdullah Abusorrah
The recent development of channel technology has promised to reduce the transaction verification time in blockchain operations. When transactions are transmitted through the channels created by nodes, the nodes need to cooperate with each other. If one party refuses to do so, the channel is unstable. A stable channel is thus required. Because nodes may show uncooperative behavior, they may have a negative impact on the stability of such channels. In order to address this issue, this work proposes a dynamic evolutionary game model based on node behavior. This model considers various defense strategies' cost and attack success ratio under them. Nodes can dynamically adjust their strategies according to the behavior of attackers to achieve their effective defense. The equilibrium stability of the proposed model can be achieved. The proposed model can be applied to general channel networks. It is compared with two state-of-the-art blockchain channels: Lightning network and Spirit channels. The experimental results show that the proposed model can be used to improve a channel's stability and keep it in a good cooperative stable state. Thus its use enables a blockchain to enjoy higher transaction success ratio and lower transaction transmission delay than the use of its two peers.
In emergency scenarios where the on-site information is completely lacking or the original environmental state has been completely changed, autonomous and mobile swarm robotics are used to quickly build a rescue support system to ensure the safety of follow-up rescuers and improve rescue efficiency. To address the data security problem caused by the complex and changeable topology of the heterogeneous swarm robotics network in the process of building the rescue support system, this paper introduced a decentralized data security communication scheme for heterogeneous swarm robotics. First, we built a decentralized network topology model by using base robot, communication robotics, and business robotics, and it can ensure the stability of the system. Moreover, based on the decentralized network topology model, we designed a storage model using the master-slave blockchain method. The master chain is composed of base robot and communication robotics, which mainly store the digests of robot data in multiple slave chains to reach the global data consensus of the system. The slave chains are composed of business robotics and communication robotics, which mainly store all data on the slave chains to reach the local data consensus of the system. The whole data storage system adopts the Delegated Proof of Stake consensus mechanism to elect proxy nodes to participate in the data consensus tasks in the system and to ensure the data consistency of each robot node in the decentralized network. Additionally, a prototype of the heterogeneous swarm robotics system based on the master-slave chains is constructed to verify the effectiveness of the proposed model. The experimental results show that the scheme effectively solves the data security problem caused by the unstable communication link of the heterogeneous swarm robotics system.
This paper proposes a hunger relief network based on crypto-currency and a hybrid mix of centralized and decentralized databases which is totally formed by the volunteers and donors and is out of control of centralized organizations. The centralized part of the database maintains non-sensitive information with less need to security features, mainly providing motivative information for donors and giving feedback to know that how their gifts were spent. The decentralized part of the design is based on a third-generation Distributed Ledger Technology which contains sensitive information of payments and receipts and flow of supply chain, which is designed to be fast, secure and fault tolerant.
In the evolution from 5G to beyond 5G networks, new business models are emerging where multi-domain and multistakeholder scenarios will play a paramount role as enablers. In these scenarios, the automated management of the services with minimal human intervention, also known as zero-touch management, is a pivotal requirement to ensure a proper functioning and to enable real-time responses to possible incidents or scalability needs. Nonetheless, these new scenarios and requirements also introduce new security risks that entail a complex threat landscape for beyond 5G networks. Hence, zero-touch management demands new solutions capable of securely controlling network resources into end-to-end scenarios distributed in multiple domains. In this vein, several challenges arise and need to be addressed, such as integrity, non-repudiation, confidentiality, security, and trust. Therefore, the H2020 5GZORRO project proposes new security and trust solutions for multi-domain and multi-stakeholder scenarios in 5G and beyond networks. To deal with the utmost importance security and trust challenges, we introduce different modules to mitigate them, namely, integrity and non-repudiation through Distributed Ledger Technologies, decentralized identity through an Identity and Permission Manager, end-to-end trustworthy relationships via a Trust Management Framework, secure workloads across different tenants and stakeholders via Trusted Execution Environment Security Management, detection and response to internal vulnerabilities and attacks via Network Monitoring, and on-demand secure cross-domain connections via VPN-as-a-Service. Therefore, the built security and trust 5GZORRO mechanisms form a secure environment with zero-touch automation capabilities, minimizing human intervention.
Reliable communication is a critical component of a successful emergency management operation in resilient cities. However, large-scale extreme events may demolish telecommunication infrastructure. The current state of practice to maintain communication when telecom infrastructure are not available heavily depend on expensive equipment (e.g., transportable telecom towers and unmanned aerial networks) that may not be readily available everywhere. To address this issue, this study aims to develop theoretical foundations for a new framework that provides a fully decentralized infrastructure-less communication system using ad hoc mobile networks. The proposed framework uses device-to-device (D2D) wireless connection, distributed ledgers adopted from Blockchain technology, and a new all-to-all network broadcasting algorithm. The proposed infrastructure-less system collects critical spatial data from available cellphone devices in the affected area and shares it among all of them. At the end of this procedure, each device will have spatial information of all available devices. When emergency teams find a device through a D2D connection, they will actually have access to spatial data of all devices and can locate all people in one step.
Hong‐Ning Dai, Yulei Wu, Muhammad Imran, Nidal Nasser
Space-air-ground-sea integrated networks (SAGSINs) are promising to offer ubiquitous Internet services across the globe while confronting research challenges such as security vulnerabilities, privacy leakage concerns, and difficulty in resource sharing. On one hand, emerging network slicing and network softwarization technologies can fulfill diverse requirements with the provision of various services on top of heterogeneous SAGSIN hardware and software resources. On the other hand, blockchain and smart contracts can compensate for network slicing and softwarization to offer secure and automatic network services. This article presents an investigation on the convergence of blockchains with network slicing and network softwarization technologies for SAGSINs from the perspectives of network management and brokerage services of SAGSINs. In contrast to existing studies, this article is the first to incorporate blockchains into network slicing and network softwarization dedicated for SAGSINs. This article starts with a summary of key characteristics and challenges of SAGSINs. Then a review of network slicing and network softwarization is given in the context of SAGSINs. This article next presents an integrated framework of network slicing, network softwarization, and blockchain for SAGSINs. Moreover, this article outlines a set of open issues and research challenges that would be useful to guide future research in this area.
We present a new stochastic model for the evolution of Directed Acyclic Graphs (DAG)-based distributed ledgers (DL), under the presence of heterogeneous delay. This model is used to analyse the performance metrics of the DL, showing in particular that the number of unapproved messages does not diverge to infinity, even under the presence of delay. We propose an analysis based on conveniently defined sets, as well as an alternative drift-based analysis. The former allows to get a bound on the number of unapproved messages, while the latter, through a simpler analysis, allows to probe the existence of such bound. For particular scenarios, we are able to derive the expected value of the drift of unapproved messages, through a Markov process-based approach. State-of-the-art mathematical models trying to capture the impact of delays on the performance of such DLs rely on some particular simplifications. In contrast, through our model, we are able to analytically derive similar performance guarantees, in a more realistic setup. In particular, we focus on IOTA foundation's tangle, while our results can be extended to other DAG-based distributed ledgers. We compare our results to results obtained in a real testbed, showing good accordance between them.
Quinten Stokkink, Can Umut Ileri, Dick Epema, Johan Pouwelse
Web3 is emerging as the new Internet-interaction model that facilitates direct collaboration between strangers without a need for prior trust between network participants and without central authorities. However, one of its shortcomings is the lack of a defense mechanism against the ability of a single user to generate a surplus of identities, known as the Sybil attack. Web3 has a Sybil attack problem because it uses peer sampling to establish connections between users. We evaluate the promising but underexplored direction of Sybil avoidance using network latency measurements, according to which two identities with equal latencies are suspected to be operated from the same node, and thus are likely Sybils. Network latency measurements have two desirable properties: they are only malleable by attackers by adding latency, and they do not require any trust between network participants. Our basic SybilSys mechanism avoids Sybil attackers using only network latency measurements if attackers do not actively exploit their malleability. We present an enhanced version of SybilSys that protects against targeted attacks using a variant of the flow correlation attack, which we name TrafficJamTrigger. We show how the message flows of Round-Trip Time measurements can be used to expose attack patterns and we propose and evaluate six classifiers to recognize these patterns. Our experiments show, through both emulation and real-world deployment, that enhanced SybilSys can serve a fundamental role for Web3, effectively establishing connections to real users even in the face of networks consisting of 99% Sybils.
A cryptocurrency token airdrop is a novel means of distributing rights over a blockchain project to a community of users and owners for free. The market value of these airdrop giveaways is often upwards of hundreds of millions of dollars. This paper considers why projects might choose this unusual and costly means of token distribution. It considers a diverse selection of high-profile airdrops as case studies between 2014 and 2022. This is the first comprehensive analysis of the rationales and mechanisms of Web3 token airdrops. We find that two primary rationales for airdrops are marketing (to attract new users and to maintain a community) and decentralisation of ownership and control of a project (building community, providing regulatory protection, and enhancing security). Additional rationales include creating liquid public markets and taxation treatment of token distribution. The paper contributes to an understanding of business practice and strategy in the emerging cryptocurrency and blockchain industry.
Due to the mobility of devices, device-to-device (D2D) communication is a promising fifth-generation (5G) technology in dynamic environments for improving message transmission efficiency for group communication. Additionally, all services in an ad hoc network are current Vehicle Ad Hoc Network (VANET) applications. Therefore, D2D communication has been introduced in ad hoc environments to reduce latency during vehicle conversations, such as autonomous vehicle solutions and drone fleet management for cellular vehicle-to-everything (C-V2X) modules and Internet of Drones (IoDs) networks. However, providing secure and effective group communication is an urgent challenge. To solve these problems, we propose a dynamic group management solution based on distributed ledger technology. This study demonstrates that a distributed ledger-based hierarchical architecture for dynamic group management is faster and more adaptable without compromising security and performance. Furthermore, the proposed method can facilitate the transfer of direct communication data without a centralized database, thereby reducing the chance of a single point of failure. In addition, the research was tested by a third party that has established close cooperation with world-leading automotive electronics suppliers in Taiwan.
In the aftermath of a disaster, natural or man-made, successful emergency management operations vitally depend on reliable communication infrastructures. However, large-scale extreme events may dismantle telecommunication infrastructures and impair rescue operations. The current state of practice to maintain communication when infrastructures are not operable mostly focuses on using temporary infrastructures including mobile telecom towers. However, these centralized solutions heavily depend on equipment that may not be readily available. To address this issue, this paper aims to create theoretical foundations for, and empirically examine the performance of, a novel decentralized and infrastructure-less communication system that uses an ad hoc mobile network, distributed ledger and Blockchain technology, and an all-to-all broadcasting routing algorithm. When the proposed communication system is used, mobile devices in the affected area connect with each other through device-to-device Wi-Fi Direct, create a temporary mobile ad hoc network, and share spatial information through the stepwise routing algorithm and distributed ledgers. At the end of this process, each device in the network will have spatial information of all available devices in the area. Therefore, when first responders arrive in the affected area, they can locate all devices and have access to all collected information immediately through a direct connection to only one device in the area. The outcomes of this study will fundamentally transform the emergency communication solutions and can significantly shorten the duration of rescue operations by helping first responders locate citizens in the affected area faster and more efficiently.
Yoshito Watanabe, So Hasegawa, Mikio Hasegawa, Yozo Shoji
This paper proposes a novel framework for transaction record management using distributed ledger technology over the “piggy-back network”, which is an opportunistic network composed of mid-range control plane and short-range data plane with heterogeneous wireless standards. In the network, mobile nodes such as service robots perform sensing by, e.g., recording video and try to disseminate the large-volume sensing data contents to other nodes via the data plane by a store-carryforward (SCF) principle. To manage the transaction records that represent event histories in the network, we employ a distributed ledger, where our previously proposed Proof-of-Forwarding (PoF) technique is used for block generation; a block is generated at the timing of completing data exchange. We design the ledger to have a directed acyclic graph (DAG) structure to work in an opportunistic network. By synchronizing the ledgers between nodes over the control plane, every node can grasp the differences of the databases owned by individual nodes, and this knowledge is utilized to determine if the node-to-node data exchange via the data plane is necessary. The computer simulations show that, compared to a conventional blockchain, the proposed DAG-based ledger can achieve a lower delay for disseminating transaction records across all nodes. In contrast, large delays are caused in a conventional blockchain system due to its single-branch structure.
Kailei Tang, Zhiyan Dong, Tianlun Dai, Zhongxue Gan
The issues of managing swarm intelligence are essential to many multiple tasks. The scenarios are complex and dynamic, which is hard for a single agent to satisfy the needs of various tasks. As thus, a practical intelligence cooperative combat scheme, composed of multiple agents, is required to supply a effective and efficient consensus for swarm intelligence with external conditions evolving. Among this scheme, the accuracy of information sharing, transmission, and the integrity of the stored data are all critically significant. The Blockchain, a digital distributed ledger,is distributed on different nodes, and each node holds the same data, which attracts increasing attentions recently. There are many consensus algorithms which is the key part of the blockchain, such as PoW, PoS, DPoS, PoR, etc. However, no matter in terms of performance, security and stability, existing work can hardly support a battle plan oriented to swarm intelligence. To our knowledge, there is no consensus algorithm that takes into account the resources of agent in swarm intelligence collaboration. Therefore, we introduce an optimization of DPoS for swarm intelligence based on agent behavior monitoring and agent’s own resource analysis (Delegated Proof of Stake based node’s Behavior and Resource, DPoSBR). Combining the situation of malicious behaviors of the agent and the resources of the agent, we choose the more trustworthy agent as the captain. Therefore, the captain agent is more secure and the election process is fairer. Finally, the extensive simulations are conducted to evaluate the performance of DPoSBR algorithm, which has good practicability. Meanwhile, it enables more agents to participate, which is beneficial to the decentralization of the system and can promote the enthusiasm of the entire agents, and it prevents the malicious agents from doing malicious behaviors again.
Intrusion Detection Systems (IDS) have been the industry standard for securing IoT networks against known attacks. To increase the capability of an IDS, researchers proposed the concept of blockchain-based Collaborative-IDS (CIDS), wherein blockchain acts as a decentralised platform allowing collaboration between CIDS nodes to share intrusion related information, such as intrusion alarms and detection rules. However, proposals in blockchain-based CIDS overlook the importance of continuous evaluation of the trustworthiness of each node and generally work based on the assumption that the nodes are always honest. In this paper, we propose a decentralised CIDS that emphasises the importance of building trust between CIDS nodes. In our proposed solution, each CIDS node exchanges detection rules to help other nodes detect new types of intrusion. Our architecture offloads the trust computation to the blockchain and utilises a decentralised storage to host the shared trustworthy detection rules, ensuring scalability. Our implementation in a lab-scale testbed shows that the our solution is feasible and performs within the expected benchmarks of the Ethereum platform.
Kuo Chuen LEE David, Joseph J. Lim, Kok Fai Phoon, Yu Wang
Consensus is a key concept in Blockchain and Distributed Ledger Technologies. Blockchain networks are distributed in a manner whereby participants do not necessarily know or trust each other. This makes agreeing on the state of the network challenging, particularly when there may be bad actors. Consensus protocols are designed to achieve agreements within the network and to ensure that participants act in the best interest of the network.
For first responders entering into a post-disaster situation, there is usually a severe lack of up-to-date ground truth. The initial period of time has multiple sources of conflicting information coming in and creating confusion about the situation. The most important immediate requirement is to create a traversal map, highlighting navigable paths to victims of the disaster and possible hazardous locations. Due to infrastructure damage, it is hard for existing centralized geospatial portals to quickly update and provide this information, which has become outdated. IoT solutions that can be deployed without extensive preparation provide the capability to quickly acquire and disseminate essential information to rescue teams. In this paper, we present a decentralized system, named DEIMOSBC, that is able to provide such a mapping service faster and more reliably, utilizing the work of volunteers and relying on a blockchain backend that is based on an IoT system. Our solution utilizes the availability of modern smartphones with GPS receivers and processing capabilities to collect sequences of GPS locations and chain them into trajectories. These trajectory data are submitted as entries into a blockchain after cleaning them through a purpose-built smart contract. DEIMOSBC relies on the inherent robustness and distributed nature of a blockchain to make collating and assembling a map from these paths more accurate and less susceptible to disruption. We describe how DEIMOSBC would work for a hypothetical disaster scenario of a Category 5 hurricane striking an area of the Gulf of Mexico.
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). Sophisticated applications, like cryptocurrencies, need distributed ledgers (DLs) to function. DLs, 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 DLs are not deployable to D2D ecosystems since their storage needs are continuously increasing. In this work, we introduce and analyze Mneme, a DAG-based DL that can be maintained solely by mobile devices. Mneme utilizes two novel consensus protocols: 1) Proof of Context (PoC) and 2) 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 Mneme’s security and justify the ability of PoC and PoE to guarantee the characteristics of DLs: 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.
Nitin Gupta, Jagdeep Singh, Sanjay Kumar Dhurandher, Zhu Han
Industrial Internet of Things (IoT) and Industry 4.0 enable interconnection among various devices. An opportunistic IoT network is an ad hoc network that is formed by the nodes (e.g., smart vehicles and mobile phones) by utilizing various short radio range techniques. In this kind of network, information forwarding and dissemination among other smart devices is based upon the opportunistic contact nature mainly due to network dynamics and user mobility. Routing plays an important part in these kinds of networks since there does not exist a pre-established route (Tyagi and Kumar, 2013). Nodes are often selected dynamically based upon many parameters such that messages can be delivered successfully to the destination devices or sinks. However, these intermediate nodes are often selfish because routing these packets costs energy. In the case of incomplete cooperation and asymmetric information, message delivery can be severely degraded, which increases the network delay affecting the overall network performance. Therefore, this work proposes an incentive design mechanism based on the contract theory to reward intermediate nodes appropriately to forward the messages. The contract theory is used to model the forwarding-forwarder node interaction as a labor market with private information. First, the users are classified into a finite number of types according to their ability of forwarding the message, and the service trading between the forwarding and forwarder nodes is properly modeled. Furthermore, the necessary and sufficient conditions are derived to provide the incentives to the nodes involved in the message forwarding. Extensive simulations show that the proposed mechanism is effective in providing incentives and outperforms other benchmark schemes in terms of delivery probability, average latency, and overhead ratio.