Blockchain Papers

Kai Lei, Junjie Fang, Qichao Zhang, Junjun Lou · 8 authors

No abstract is available for this record.

Andra Lutu, Marcelo Bagnulo, Diego Perino

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.

Meng Li, F. Richard Yu, Pengbo Si, Wenjun Wu · 5 authors

Recently, the development of the Internet of Things (IoT) provides plenty of opportunities and challenges in various fields. As an essential part of IoT, machine-to-machine (M2M) communications open a novel way that the machine-type communication devices (MTCDs) are connected and communicated without any human intervention. Meanwhile, delay-tolerant data play an important role in M2M communications-based IoT, and it puts more emphasis on powerful data caching, computing, and processing, as well as the security and stability of data transmission. To meet these requirements in M2M communications networks, in this article, we introduce some promising technologies, such as edge computing and blockchain, and propose a joint optimization framework about caching, computation, and security for delay-tolerant data in M2M communications networks based on dueling deep Q-network (DQN). According to the dynamic decision process by DQN, the optimal selection and decision of caching servers, computing servers, and blockchain systems can be made to achieve maximum system rewards, which includes higher efficiency of data processing, lower network costs, and better security of data interaction. Extensive simulation results with different system parameters show that our proposed framework can effectively improve the system performance for blockchain-enabled M2M communications compared to the existing schemes.

Mirko Zichichi, Stefano Ferretti, Gabriele D’Angelo

This paper presents an architecture, based on Distributed Ledger Technologies\n(DLTs) and Decentralized File Storage (DFS) systems, to support the use of\nPersonal Information Management Systems (PIMS). DLT and DFS are used to manage\ndata sensed by mobile users equipped with devices with sensing capability. DLTs\nguarantee the immutability, traceability and verifiability of references to\npersonal data, that are stored in DFS. In fact, the inclusion of data digests\nin the DLT makes it possible to obtain an unalterable reference and a\ntamper-proof log, while remaining compliant with the regulations on personal\ndata, i.e. GDPR. We provide an experimental evaluation on the feasibility of\nthe use of DFS. Three different scenarios have been studied: i) a proprietary\nIPFS approach with a dedicated node interfacing with the data producers, ii) a\npublic IPFS service and iii) Sia Skynet. Results show that through proper\nconfiguration of the system infrastructure, it is viable to build a\ndecentralized Personal Data Storage (PDS).\n

Mirko Zichichi, Stefano Ferretti, Gabriele D’Angelo

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.

Víctor Garcia-Font

No abstract is available for this record.

Hakima Khelifi, Senlin Luo, Boubakr Nour, Hassine Moungla · 6 authors

No abstract is available for this record.

Zhenzhen Jiao, Baoxian Zhang, Li Zhang, Min Liu · 6 authors

Mobile ad-hoc cloud can exploit the computing resources (e.g., smartphones, vehicles, and unmanned systems) scattered in the mobile environment to form a self-organized ad-hoc local resource pool for providing opportunistic computing services. However, the highly dynamic and distributed characteristics of the mobile ad-hoc network environment bring great challenges in privacy and security in such opportunistic resource sharing. In this article, we first discuss the attractive features of blockchain for providing such resource sharing services in the mobile ad-hoc network environment in a secure and trustful way and then discuss the problems caused when using existing consensus protocols in such an environment. We accordingly devise a blockchain based trustful mobile ad-hoc cloud architecture, AdChain cloud. We describe the functions at different layers in this architecture, including the network layer, blockchain layer, and smart contract layer. To adapt to the high dynamics of the mobile ad-hoc network environment, we design a stability-aware consensus protocol at the blockchain layer. Simulation results show that our solution can achieve improved performance as compared with existing work.

Marc Jayson Baucas, Petros Spachos

An Internet of Things (IoT) network can have different components such as servers, gateways, and the end devices. An important source of performance constraint in such an IoT network is found in the limitations of its gateway. The capability of a gateway can dictate the effectiveness of a network and its services. The capacity, power consumption, and security of an IoT gateway are revealed as sources of network bottlenecks and service constraints. Blockchain technology can create a decentralized structure that can offload these strains. To unify these nodes as gateways under the same network, we need an effective means of communication. This paper proposes a setup that makes use of the decentralized capabilities of private blockchain technology partnered with the low-powered and secure connection of Bluetooth Low Energy (BLE). This provides a more secure means of wireless communication and prevents the nodes from being concentrated within an area. The architecture was compared against a standard WiFi network (2.4GHz) to prove its feasibility in effectively carrying out its functionality. In an experiment that used 4 gateway nodes, BLE proved to be more feasible than WiFi by yielding a better verification packet rate of 14 per minute compared to its counterpart that measured 4 per minute. Also, it showed to be more efficient in terms of power consumption with an average of 1095.40 mW, while the WiFi setup was measured to be 1191.83 mW. These results show promise in using BLE paired with blockchain technology to solve the capacity, power and security issues in IoT networks.

Alexandros Bampoulidis, A. Bruni, Lukas Helminger, Daniel Kales · 6 authors

Recent work has shown that cell phone mobility data has the unique potential to create accurate models for human mobility and consequently the spread of infected diseases [74]. While prior studies have exclusively relied on a mobile network operator’s subscribers’ aggregated data in modelling disease dynamics, it may be preferable to contemplate aggregated mobility data of infected individuals only. Clearly, naively linking mobile phone data with health records would violate privacy by either allowing to track mobility patterns of infected individuals, leak information on who is infected, or both. This work aims to develop a solution that reports the aggregated mobile phone location data of infected individuals while still maintaining compliance with privacy expectations. To achieve privacy, we use homomorphic encryption, validation techniques derived from zero-knowledge proofs, and differential privacy. Our protocol’s open-source implementation can process eight million subscribers in 70 minutes.

Alexandros Bampoulidis, A. Bruni, Lukas Helminger, Daniel Kales · 6 authors

Recent work has shown that cell phone mobility data has the unique potential\nto create accurate models for human mobility and consequently the spread of\ninfected diseases. While prior studies have exclusively relied on a mobile\nnetwork operator's subscribers' aggregated data in modelling disease dynamics,\nit may be preferable to contemplate aggregated mobility data of infected\nindividuals only. Clearly, naively linking mobile phone data with health\nrecords would violate privacy by either allowing to track mobility patterns of\ninfected individuals, leak information on who is infected, or both. This work\naims to develop a solution that reports the aggregated mobile phone location\ndata of infected individuals while still maintaining compliance with privacy\nexpectations. To achieve privacy, we use homomorphic encryption, validation\ntechniques derived from zero-knowledge proofs, and differential privacy. Our\nprotocol's open-source implementation can process eight million subscribers in\n70 minutes.\n

Martin Martinez, Arvin Hekmati, Bhaskar Krishnamachari, Seokgu Yun

We present a novel “Proof of Social Contact” approach to Sybil control that utilizes the analysis of digitally signed information about digitally signed pairwise encounters between mobile devices that are logged in a distributed ledger. To illustrate the approach, we show examples of analysis using binary classification techniques under two different adversary detection models, and evaluate them using a real-world mobile device encounter trace. We discuss a number of open problems and future directions that could be pursued by researchers in the field to realize and improve such a system and build on top of it.

Anik Islam, Soo Young Shin

No abstract is available for this record.

Lillian Clark, Yeh-Ching Tung, Matthew Clark, Laurence F. Zapanta

Currently, space communications networks are attempting to move away from large geostationary (GEO) satellites towards large constellations of small satellites. This trend is observed both in government and commercial communications satellites. By relaying data across multiple constellations/networks, we may be able to reduce end-to-end latencies and reduce burden (mass, power, cost) for all users. However, this is only possible if networks across constellations can establish inter-satellite authentication and trust. The key to this trust is based on demonstrated ability of the relay satellites to meet performance requirements, i.e. “reputation.” In this work, we propose leveraging distributed ledger technologies (i.e. blockchains) to develop a secure, decentralized reputation system for satellite relay networks. This informs a reputation-aware routing protocol and reduces the average data latency across the network. In this paper, we discuss designing the blockchain-based reputation system and routing protocol. We then analyze the resultant network performance with respect to average latency, computational complexity, and storage considerations for a variety of use cases.

Priya Singh, Pooja Khanna, Sachin Kumar

Vehicular ad hoc networks (VANETs),is a new concept in the direction of making human life more comfortable and secure. Starting with the invention of wheel the journey of the road communication has reached to a point of driverless vehicles. Road communication is the widely spread and most preferred way of commuting the places. This is the reason to create a safer infrastructure for road transportation. Present work is a study about Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communications architecture. On-Board Units (OBUs) enabled vehicle in the market can form a Vehicular Ad Hoc Networks (VANETs) that allow wireless communication in a completely distributed manner while they can communicate with Roadside Units (RSUs) in an infrastructure mode. The work presented here also proposed a hybrid Block chain Communication Architecture that will ensure more security in V2V and V2I communication.

Kashish Khullar, Yishu Malhotra, Anupam Kumar

Flying Ad Hoc networks, (FANETs) in recent years, have actively been used in monitoring landscape, military and mapping terrains. However, with the advent of the emerging concept of smart cities and new business applications, these flying devices and drones have found a new use case in the medical and governance sector. But these networks suffer from the major problem of centralization. Although centralization does provide reliability and efficiency but also poses the threat of a single point of failure. Meanwhile, blockchain widely known for its decentralization is heavily researched and can be utilized in this case to offer a solution to the problem of centralization of FANETs. Therefore, in this paper, we propose a decentralized architecture of flying ad hoc nodes based on blockchain and using Practical byzantine fault tolerance (PBFT) for consensus among nodes. By employing PBFT, the architecture is not only computationally efficient and fast. In addition, we have used a gossip protocol for passing messages among nodes. Lastly, we have simulated the working of our model and the experimental results show that the proposed method works with nearly constant throughput and latency while increasing the network size and approximately constant message overhead with increase transaction for given network size.

Alexandre Pacheco, Volker Strobel, Marco Dorigo

No abstract is available for this record.

Yang Qin, Tiantian Zhang, Mengya Li

No abstract is available for this record.

Maqsood Ahamed Abdul Careem, Aveek Dutta

One of the core issues in routing packets within Mobile Ad hoc Networks (MANETs) is the lack of trust and reputation of the participating nodes, which often leads to unreliable packet delivery. We use a fraction of nodes to validate routing actions taken by other nodes and leverage the distributed consensus mechanism in Blockchain networks to accrue the reputation of each node. Specifically, we employ heterogeneous difficulty for Proof of Work to represent the credibility of validation and design a scoring system to isolate malicious nodes via distributed consensus. The reputation of a node is then based on the combination of the difficulty level and the score. This reputation is incorporated in a novel routing metric to calculate the shortest, most reputed path between a source and destination node. The goal is to discourage malicious nodes by excluding those from participating in routing packets. A joint simulation of the Blockchain and routing algorithm reveal ≈12% improvement in overall packet delivery in the presence of routing attacks, compared to conventional routing algorithms in MANETs.

Ronald Doku, Danda B. Rawat, Moses Garuba, Laurent Njilla

Named Data Network's (NDN) data-centric approach makes it a suitable solution in a networking scenario where there are connectivity issues as a result of the dynamism of the network. Coupling of this ability with the blockchain's well-documented immutable trustworthy-distributed ledger feature, the union of blockchain and NDN in an Internet-of-Battlefield-Things (IoBT) setting could prove to be the ideal alliance that would guarantee data exchanged in an IoBT environment is trusted and less susceptible to cyber-attacks and packet losses. Various blockchain technologies, however, require that each node has a ledger that stores information or transactions in a chain of blocks. This poses an issue as nodes in an IoBT setting have varying computing and storage resources. Moreover, most of the nodes in the IoT/IoBT network are plagued with limited resources. As such, there needs to be an approach that ensures that the limited resources of these nodes are efficiently utilized. In this paper, we investigate an approach that merges blockchain and NDN to efficiently utilize the resources of these resource-constrained nodes by only storing relevant information on each node's ledger. Furthermore, we propose a sharding technique called an Interest Group and introduce a novel consensus mechanism called Proof of Common Interest. Performance of the proposed approach is evaluated using numerical results.

Tingting Song, Bo Cui, Ru Li, Jing Liu · 5 authors

Named Data Networking (NDN) is a new clean-slate architecture for the future Internet. Efficient content retrieval is the original intention of NDN design. The content retrieval process driven by content consumers in NDN includes the following challenges, consumers do not know whether the content exists and whether the content producer is reliable. Invalid interest packets could cause the occupation of limited network resources and DoS attack problem. To ensure the authenticity and integrity of the data packets, consumers need to pre-configure the trust schema, which is centralized and prone to the single point of failure problem. Blockchain has widespread attention to build trust in a distributed way, and Ethereum is a programmable blockchain, a decentralized smart contract platform. To lighten the burden of consumers, we proposed a Smart Contract-based Trusted Content Retrieval Mechanism (SCTCRM) for NDN in this paper. The mechanism contains a trustworthy information base for content and producers based on smart contracts, and provides content retrieval and name resolution services for content consumers. The purpose of this mechanism is to improve the efficiency and security of content retrieval process. We described the framework and the workflow of SCTCRM, and used Colored Petri Nets to create a formal mathematical model and analyze the security of the mechanism. Finally, the cost of storage and Gas in smart contracts are evaluated through the prototype deployment. From the results, we can see that the proposed mechanism is security and practicality.

Maria Olsson

With the rise in popularity of cryptocurrencies, distributed ledger technology is a term that has gained traction. The aim of this study is to review and comparethe distributed ledger technologies blockchain and directed acyclic graph, examining their internal structures as well as some platforms and existing areas of application. An implementation, the goal of which is to illustrate the components of a possible distributed ledger solution and how they might interact, has been made in the form of a smart contract deployed on a simulated distributed ledger network. To give some explanation to the foundations of distributed ledger technology, a brief overview is given on the topics of cryptography, underlying data structures, and the frameworks used in this study. The literature study has been conducted by collecting and reviewing primarily scientific articles on the topic of distributed ledger technologies and consensus algorithms, as well as white papers on selected distributed ledger platforms. The construction has been done using the framework Hyperledger Fabric. The result chapter reviews how the implemented smart contract fulfills the concrete goals. The study is concluded with a discussion regarding how distributed ledgers might possibly be used in thef uture, what might be done to further develop the implemented smart contract and some of the ethical concerns surrounding distributed ledger technology.

Christos Patsonakis, Mema Roussopoulos

Asynchronous rumor spreading, or epidemic algorithms, are a class of data dissemination protocols that have been used throughout the years for a large variety of distributed applications. The emergence of large-scale, public blockchains, such as Bitcoin and Ethereum, has reinvigorated research interest in these protocols as they are employed to disseminate pending transactions and confirmed blocks in their peer-to-peer (P2P) networks. Efficient, timely and fault-tolerant information dissemination is vital for blockchain networks as it affects issues ranging from security to block finality. Recent works have analyzed the structural properties of blockchain network overlay graphs. Their findings show that they have inherent similarities to those of social networks, such as power-law degree distributions, small diameters and star-like communities. In this work, we present an experimental analysis of the vanilla asynchronous push & pull rumor spreading protocol that is employed by public blockchains. This protocol, although robust and scalable, can be substantially improved. We demonstrate this by analyzing the effect that multiple parameters have on the protocol's performance, such as using memory to avoid contacting the same neighbor twice in a row, varying the stopping criteria of nodes to decide when to stop spreading the rumor, employing more sophisticated neighbor selection policies instead of the standard uniform random choice and others. Prior works have focused on either providing theoretical upper bounds on the number of rounds needed to spread the rumor to all nodes, or, propose improvements by adjusting isolated parameters. To our knowledge, our work is the first to study how multiple parameters affect the protocol's behavior both in isolation and combination and under a wide range of values. Moreover, prior theoretical works have studied rumor spreading only on bidirectional social topologies. Our study examines the behavior of the protocol in multiple topology classes. These include bidirectional, directed, and also a special type of social topologies, called signed topologies, which resemble more closely the topologies of blockchain P2P networks. Our work is the first to indicate and deal with how chains of communities that are sparsely connected to the core of the network can hamper the rumor's spreading. Thus, we complement prior theoretical work to shed light on how the protocol behaves in practical, real-world, large scale distributed systems. Finally, through our detailed analysis, we demonstrate how a few simple additions to the protocol deliver a percentage decrease of the time required to inform all nodes by a maximum of 99.69% and an average of 86.04%.