Blockchain Papers

Nickolas Carter, Peter Pommer, Duane Davis, Cynthia E. Irvine

No abstract is available for this record.

Hao Liu, Rongbo Zhu, Jun Wang, Wengang Xu

Due to the distributed and dynamic characteristics of the Internet of Vehicles (IoV) and the continuous growth in the number of devices, content-centric decentralized vehicular named data networking (VNDN) has become more suitable for content-oriented applications in IoV. However, the existing centralized architecture is prone to the failure of single points, which results in trust problems in key verification between cross-domain nodes and consuming more power and reducing the lifetime. Focusing on secure key management and power-efficient routing, this article proposes a blockchain-based key management and green routing scheme for VNDN. A blockchain-based key management scheme is presented to achieve secure and efficient distribution and verification of keys. Specifically, all trusted agencies (TAs) form a consortium blockchain for storing public key hashes to ensure the authenticity of users’ public keys. A green global routing scheme based on node relaying pressure (GGNRP) is proposed to save power consumption and reduce the forwarding delay. A new node relay pressure metric is introduced to assist with routing decisions. Detailed experiments and analysis show that, compared with the existing scheme, the proposed scheme can achieve secure key management and GGNRP can decrease the power consumption and average delay by 15.8% and 63.2%, respectively.

Liang Zhao, Muhammad Bin Saif, Ammar Hawbani, Geyong Min · 6 authors

Flying Ad hoc Network (FANET) has drawn significant consideration due to its rapid advancements and extensive use in civil applications. However, the characteristics of FANET including high mobility, limited resources, and distributed nature, have posed a new challenge to develop a secure and efficient routing scheme for FANET. To overcome these challenges, this paper proposes a novel cluster based secure routing scheme, which aims to solve the routing and data security problem of FANET. In this scheme, the optimal cluster head selection is based on residual energy, online time, reputation, blockchain transactions, mobility, and connectivity by using Improved Artificial Bee Colony Optimization (IABC). The proposed IABC utilizes two different search equations for employee bee and onlooker bee to enhance convergence rate and exploitation abilities. Further, a lightweight blockchain consensus algorithm, AI-Proof of Witness Consensus Algorithm (AI-PoWCA) is proposed, which utilizes the optimal cluster head for mining. In AI-PoWCA, the concept of the witness for block verification is also involved to make the proposed scheme resource efficient and highly resilient against 51% attack. Simulation results demonstrate that the proposed scheme outperforms its counterparts and achieves up to 90% packet delivery ratio, lowest end-to-end delay, highest throughput, resilience against security attacks, and superior in block processing time.

Zijian Bao, Min Luo, Huaqun Wang, Kim‐Kwang Raymond Choo · 5 authors

Space information networks (SINs) can be viewed as an expansion of a conventional network with a strong demand for high-speed, reliable, and real-time wireless communication, especially in extreme circumstances. However, there are a number of challenges associated with deploying SINs. With the emergence and wide application of blockchain technology, it is expected to relieve the trust issues of communication systems in SINs. In this article, we first propose a decentralized blockchain architecture for SINs, taking advantage of the increasing computation and communication capabilities of satellites. Then, by utilizing blockchain, we present two communication protocols, Fulgor and Rayo, designed for different application scenarios in SINs: Fulgor is a secure communication protocol between users and the ground station based on our proposed efficient authentication and key agreement protocol. Rayo is a user-to-user priva-cy-preserving communication protocol to protect the user's privacy and avoid DoS attacks. Finally, experiments are conducted and performed on a widely known blockchain platform, Hyperledger Fabric, and the findings demonstrate our proposal's feasibility.

Siuli Roy, Souvik Basu, Soumyadip Chowdhury

Performance of cooperation-based networks, like delay tolerant networks (DTNs), are severely affected by selfish nodes that are not willing to participate in message forwarding due to resource constraints. Thus, nodes must receive satisfactory incentives to compensate their resource depletion for cooperation. The available incentive schemes for DTNs either rely on hypothetical central trusted authorities or do not use explicit digital currency that is provably secure. Blockchain, a decentralized and secure digital ledger of immutable transactions, is an attractive approach for addressing the incentive challenges in DTNs that lack central trusted authorities. Ethereum, the blockchain-based cryptocurrency, makes it possible to devise practical credit-based incentive schemes for such networks. However, the usage of blockchain is restricted by the availability of end-to-end Internet connectivity, which restricts the use of blockchain in intermittently connected networks like DTNs and has prompted exploration of new mechanisms for using blockchain in such networks. This chapter first proposes a mechanism, based on the Ethereum platform using smart contracts in Solidity, for integrating blockchain technology with DTNs, towards exploiting the immutability and availability of blockchains in DTNs. It then develops BlockCent, a blockchain-based node incentivizing scheme for DTNs that runs on the blockchain-DTN integrated environment. The scheme uses a novel reward strategy to bring rationality to the incentivizing process. To add logic to the incentivizing method, the scheme uses a novel incentive strategy. The proposed incentivizing scheme is applied to the disaster management use case for fast transmission of relief shelter needs to the emergency operation center, thus leading to efficient disaster relief. Extensive security analysis justifies security of the proposed scheme. Exhaustive experiments conducted on the ONE simulator and the Ethereum platform substantiate the efficiency of the scheme in terms of design parameters like selfishness reduction and reward fairness, and network parameters like delivery ratio, average delay, and overhead ratio, while not compromising blockchain performance parameters like processing time and gas consumption.

Yuntao Wang, Zhou Su, Qichao Xu, Ruidong Li · 5 authors

Unmanned aerial vehicles (UAVs) have brought numerous potentials to establish flexible and reliable emergency networks in disaster areas when terrestrial communication infrastructures go down. Nevertheless, potential security threats may occur on UAVs during data transmissions due to the untrustful environment and open-access UAV networking. Moreover, UAVs typically have limited battery and computation capacity, making them unaffordable to execute heavy security provisioning operations when carrying out complicated rescue tasks. In this paper, we develop RescueChain, a secure and efficient information sharing scheme for UAV-aided disaster rescue. Specifically, we first implement a lightweight blockchain-based framework to safeguard data sharing under disasters and immutably trace misbehaving entities. A reputation-based consensus protocol is devised to adapt the weakly connected environment with improved consensus efficiency and promoted UAVs' honest behaviors. Furthermore, we introduce a novel vehicular fog computing based off-chain mechanism by leveraging ground vehicles as moving fog nodes to offload UAVs' heavy data processing and storage tasks. To optimally stimulate vehicles to share their idle computing resources, we also design a two-layer reinforcement learning based incentive algorithm for UAVs and ground vehicles in the highly dynamic networks. Simulation results show that RescueChain can effectively accelerate consensus process, enhance user payoffs, and reduce delivery latency, compared with representative existing approaches.

Xuefei Zhang, Wenbo Xia, Xiaochen Wang, Junjie Liu · 7 authors

Consensus is one of the most important issues of a blockchain system because it is a necessary process to reach an agreement between a group of separated nodes that do not trust each other in a decentralized framework. Most existing blockchain consensus works assume that the time of block propagation among separated nodes during the consensus process is ignorable, i.e., a block always successfully reaches every participating node during a period of time that is far shorter than the mining time. However, when blockchain is used in vehicularad hocnetworks (VANETs), the block propagation time is no longer negligible since the dynamic connectivity of the moving nodes in a wireless environment brings opportunistic communication to blockchain consensus. In this article, we study the impact of mobility on block propagation under the single-chain structure in VANET. Specifically, we investigate the dynamics of block propagation from the macroscopic view and derive the closed-form expression of the single-block propagation time. Then, we characterize the blockchain forking as the multiblock competitive propagation. In this way, an approximate result on multiblock propagation time is discussed. An interesting finding is that higher mobility and more moving vehicles can speed up the block propagation. In addition, we also discover that distinct propagation capabilities of moving nodes contribute to the forking reduction in the blockchain consensus.

Youssef Inedjaren

Contribution au système de transport intelligent : sécurité des communications dans les réseaux Ad hoc véhiculaires Les systèmes de transport intelligents (ITS) sont un organe vital de l'évolution du secteur du transport routier et constituent l'une des principales étapes du mouvement vers l'automatisation des véhicules. Ces systèmes utilisent des technologies permettant aux véhicules de communiquer entre eux ou avec l'infrastructure routière. En augmentant la qualité et la fiabilité des informations, les STI peuvent améliorer la sécurité routière et l'efficacité du trafic, à condition que la cybersécurité et la protection des données soient assurées.Les réseaux ad hoc de véhicules (VANET) sont une projection des ITS et sont devenus un domaine de recherche important ces dernières années. Étant de nature ad hoc et ayant une mobilité élevée comme caractéristique principale, les VANET impliquent une topologie très dynamique, ce qui signifie que la plupart des protocoles de routage dédiés aux réseaux mobiles ad hoc (MANET) nécessitent des changements remarquables pour être adéquats pour les VANET.L'objectif principal de cette thèse est d'améliorer les performances des entités physiques et des communications au sein d'un ITS en termes de sécurité. Nous nous concentrons sur la fiabilité, la connectivité et l'attaque du trou noir. Nous étudions et proposons des solutions techniques à partir de la couche réseau qui jouent un rôle fondamental dans l'atténuation des défis créés par la nature de l'environnement véhiculaire.Principalement, nos contributions sont de trois ordres. Premièrement, nous considérons les efforts visant à améliorer la fiabilité des communications dans les réseaux de véhicules. Ces efforts sont représentés par des protocoles proposés visant à assurer la livraison des messages au (x) destinataire (s). En nous concentrant sur les applications de sécurité, nous nous concentrons sur l'architecture de communication ETSI ITS, en appliquant la méthodologie Threat Vulnerability Risk Assessment (TVRA). Les résultats de notre analyse sont une liste de vulnérabilités avec leur niveau de risque de gravité. Deuxièmement, nous proposons le protocole FT-OLSR (Fuzzy Trust Optimized Link State Routing), qui est une nouvelle extension de sécurité du protocole OLSR existant. FT-OLSR est basé sur l'échange de messages de contrôle avec des voisins à un bond pour permettre à chaque véhicule de calculer le niveau de confiance de ses voisins en utilisant la logique floue. Enfin, nous proposons un système de gestion de la confiance décentralisé basé sur la blockchain. Ce système est basé sur le protocole FT-OLSR, qui utilise les messages de routage échangés (HELLO, TC) dans VANET, pour calculer les valeurs de confiance, puis détecter les véhicules du trou noir. Dans le schéma proposé, une fois que l'attaquant est identifié, il est isolé de la communication en partageant ces informations en toute sécurité sur le réseau à l'aide de la blockchain. En raison des ressources limitées des VANET, le modèle Proof-of-Trust (PoT) est inséré dans le FT-OLSR, au lieu d'utiliser Proof-of-Work ou Proof-of-Stake, dans lequel l'enjeu correspond à la valeur de confiance de chaque nœud mobile. L'algorithme de consensus PoT est utilisé pour élire les validateurs. Une fois qu'un attaquant est détecté, le validateur confirme l'intégrité du rapport et crée un bloc contenant les informations des attaquants. Le bloc est diffusé sur le réseau et ajouté à la blockchain locale de chaque véhicule. Par conséquent, si le même attaquant tente de communiquer à n'importe quel endroit du réseau, une seule recherche de la blockchain peut isoler l'attaquant.

Sanjay Kumar Dhurandher, Jagdeep Singh, Petros Nicopolitidis, Raghav Kumar · 5 authors

No abstract is available for this record.

Bin Yu, Xiaofeng Li, He Zhao, Tong Zhou

No abstract is available for this record.

Dimitris Chatzopoulos, Anurag Jain, Sujit Gujar, Boi Faltings · 5 authors

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 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 and analyse Mneme, a DAG-based distributed ledger that can be maintained solely by mobile devices. Mneme utilizes two novel 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 Mneme's security 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.

Fuliang Li, Zhenbei Guo, Changsheng Zhang, Weichao Li · 5 authors

Existing trust mechanisms in vehicular ad hoc networks (VANETs) suffer from a variety of vulnerabilities, such as trust inconsistency in different regions and fake trust values generated by a set of cooperating malicious nodes. In this paper, we propose a novel local trust management mechanism, ATM, to solve these problems. ATM employs active detection and blockchain techniques. Specifically, the active detection effectively filters the surrounding malicious nodes and prevents their active cooperation, while the blockchain ensures the consistency of trust data across different regions. We conduct numerical analysis to evaluate the performance of ATM. Our experiment results show that ATM performs the best among the three trust mechanisms under test. It can effectively identify malicious behaviors in terms of 95% detection accuracy and 90% deliver ratio, respectively.

Xiao Shu, Bo Ding, Jie Luo, Xiang Fu · 6 authors

No abstract is available for this record.

Poonam Rani, Pushpinder Pal Singh, Arnav Balyan, Jyoti Shokeen · 6 authors

No abstract is available for this record.

Yawen Tan, Jiajia Liu, Nei Kato

Unmanned aerial vehicle (UAV) is recognized as one of the best sensing tools for gathering data in the industrial Internet of things sector. Besides, the flying ad hoc network (FANET) with multiple drones shows significant advantages in complicated task performing of large area. However, as an important part of communication security, key management for FANET currently depends heavily on the base station or infrastructures, which may easily become the attack target or increase the communication overheads of drones. Therefore, we propose a blockchain-based distributed key management scheme for heterogeneous FANET in this article, based on which drones can autonomously distribute cluster keys, update their public/private key pairs, migrate between clusters, and revoke malicious UAVs in a secure way. Security analysis and performance evaluation prove that our scheme can resist against a variety of external and internal attacks, and guarantee lightweight energy consumption for ordinary drones in the network.

Lasse Orda, Oliver Gehrke, Henrik W. Bindner

No abstract is available for this record.

Dajiang Suo, Sanjay E. Sarma

Previous work on misbehavior detection and trust management can identify falsified and malicious Vehicle-to-Everything (V2X) messages and enable witness vehicles to report their observations to the trust authority for certificate management. However, there may not exist enough “benign” vehicles with V2X connectivity or vehicle owners who are willing to opt-in at an early stage of connected vehicle deployment. In this paper, we propose a security protocol for Vehicle-to-Infrastructure (V2I) communication, titled Proof-of- Travel (POT), to answer the research question: How can we transform the power of cryptography techniques embedded within the protocol into social and economic mechanisms to simultaneously incentivize V2X adoption and determine the trustworthiness of V2I data? The POT protocol determines the trust of a vehicle based on its distance traveled and the V2I information the vehicle has shared along the path of its movement. Additionally, the total vehicle mileage traveled by the vehicle must be testified by the digital signatures from infrastructure components in the vehicle's trajectory. Targeting rationale attackers motivated by profit-seeking behaviors, the POT protocol creates burdens for malicious vehicles who must acquire chains of proofs for compulsory spatial movement to gain reputation. However, the protocol does not incur extra cost for a normal vehicle who naturally moves from the origin to the destination. Instead, the verifiable vehicle mileage traveled by the normal vehicle can be used to determine its contributions and stake in the system as the altruistic behaviors of sharing observations about traffic events can benefit the transportation network. We show how to use the POT protocol to construct voting-based consensus algorithms to decide the authenticity and the correctness of vehicle-reported events and present initial simulation results.

Muhammad Arif, Walter Balzano, Alessandro Fontanella, Silvia Stranieri · 6 authors

The global internet of vehicles market is growing rapidly, it is estimated to increase significantly its value by the next few years. Vehicular Ad hoc Networks (VANETs) has a central role in the development of Intelligent Transportation System, since vehicles can communicate with each other. This paper proposes a model integrating both 5G and Blockchain for vehicular ad-hoc network management. This choice is motivated by the need of guaranteeing secure and reliable information exchange between vehicles. 5G provides low latency communication improving both V2V (Vehicle to Vehicle) and V2I (Vehicle to Infrastructure) connections increasing considerably their trustworthiness. On the other side, BlockChain offers a distributed ledger, enhancing security and data reliability. These technologies together with VANETs mechanism can provide multiple new opportunities and uses, such as automating braking system. In this work, not only we provide a complete overview of these technologies, but also we suggest a new research topic, based on the integration of such technologies with VANETs environment, to obtain a very robust network, and hence a safer traffic management.

Wen Sun, Lu Wang, Peng Wang, Yan Zhang

A space-air-ground integrated network (SAGIN) provides comprehensive interconnection and quality of service. Such an integrated network poses security concerns by bringing together a variety of devices from different untrusted authorities. Blockchain, as a decentralized ledger, although showing great potential to solve the security issues in SAGIN, may bring up intolerable latency by sequentially validating requests and take up numerous storage resources by keeping a complete replica of the entire chain in every node in a large-scale network. It becomes a feasible solution to use multiple parallel blockchains to efficiently manage different segments of SAGIN and blockchain collaboration technology to enable necessary inter-segment cooperation. Toward this end, we propose a collaborative blockchain architecture for SAGIN to achieve secure and efficient management of diverse resources. Each segment of SAGIN (i.e., space, air, and ground network) maintains a specially designed block-chain while blockchain collaboration is enabled. We then design an incentive-based collaborative blockchain for space-air-ground mobility management to encourage the participation of different network segments and ensure the security of collaboration using relay chain technology. Numerical results show the effectiveness of the proposed framework.

David Cordova Morales, Alexandre Laubé, Thi Mai Trang Nguyen, Guy Pujolle

Blockchain is one of the most prominent emerging technologies. It offers the ability to maintain an anti-tamper distributed database, ensuring the integrity and authenticity of data in a decentralized system. However, when using blockchain in a dynamic community, such as mobile nodes in an ad hoc and mesh networks, the chain structure is no longer enough to deal with node mobility. In this paper, we address the challenges of using a DAG-based blockchain for mobile and ad hoc networks (MANETs) that we call “blockgraph”. We define the characteristics of the blockgraph framework. This includes: the requirement needed for a consensus protocol in order to be resilient to network partitions; the specifications of the blockgraph protocol that ensure the maintenance of the blockgraph data structure; and a group management system that reacts to network topology changes that provide with relevant network topology information to the blockgraph framework. Finally, we implemented our framework in the discrete event network simulator NS3 as a proof-of-concept for our blockgraph.

Caciano dos Santos Machado, Carla Merkle Westphall

No abstract is available for this record.

Xintong Ling, Zheng Gao, Yuwei Le, Li You · 7 authors

In this work, we propose a satellite-aided permissionless consensus protocol for scalable space-terrestrial blockchains. We design its working principle and workflow by taking full advantage of satellites for extensive coverage and ubiquitous connectivity. Based on the proposed protocol, we demonstrate how such a space-terrestrial blockchain grows and evolves through several typical cases in the presence of adversarial nodes, user misbehavior, and transmission outage. Taking proof of work (PoW) as a benchmark, we assess the system security by considering both adversarial miners and possible colluding satellites. Then, we analyze the maximum blockchain throughput under network capacity limits and evaluate the impact of information propagation delay via a Markov model. Simulation results support that the proposed satellite-aided consensus protocol achieves higher throughput and exhibits greater scalability than PoW.

Piyumika Peiris, Chathura Rajapakse, Bimali Jayawardena

Mobile ad-hoc networks also known as MANETs have been in global use for numerous applications which are not possible with fixed network topologies. The distributed operation and dynamic topology have encouraged MANETs to be applied for establishing communication in unstable environments. MANET's dynamic topology and mobility have been very advantageous in the fields of military and disaster management. These dynamic characteristics of a MANET also create a major challenge in managing trust between the mobile nodes. Managing the trustworthiness of information that a node provides to the rest of the MANET is very crucial as misinformation spread can lead to erroneous decision making. Although previous studies have been carried out on trust management in MANETs using price-based and reputation systems, the potential of a globally distributed system has not been utilized practically. Therefore, these systems address the trust management issue within a boundary of a single MANET. Above mentioned systems should be re-evaluated when a node from another MANET joins a new MANET as the reputations of the node in the previous MANET cannot be imported to the new MANET. Lack of a possible solution for this gap may result in misinformation spreading by a malicious node before other nodes determine its reputation, which could be very dangerous in sensitive environments. Therefore, a globally distributed reputation model is a timely need in mobile ad-hoc networking. Blockchain technology is one of the most suitable technologies in present for its immutable and distributed properties to build robust systems. Blockchain is a distributed ledger, that has the ability to store feedback from mobile nodes about the accuracy of information provided by other nodes. A trust factor for each node can be calculated using these feedbacks. A mobile node can then decide whether to trust information, based on nodes’ trust factors. Adopting a development-oriented research methodology, a blockchain based reputation model prototype has been implemented and validated within the study.

P. Balakrishnan, L. Ramanathan

Cryptocurrency is a new kind of money used for purchasing goods and services via payment system that uses peer-to-peer (P2P) technology. The transactions of these currencies are cryptographically verified as well as validated without any centralized authority to monitor or regulate the money value and production of additional units of money. The primary objective of cryptocurrency is to revolutionize the way in which the global markets are connected to each other thereby clearing the barriers surrounding normative national currencies and exchange rates. In general, any cryptocurrency is composed of three sections, namely blockchain, wallets, and mining. Blockchain is a distributed ledger that bundles the transactions as blocks after the successful verification and validation using the consensus algorithm implemented in the nodes of P2P networks which are later chained together using the hash codes of each block. This chapter explains various steps involved in developing your own blockchain using Javascript which is validated using the test-driven development (TDD) approach, thereby end up with a developer friendly API.