DOCSLIB.ORG

Efficient Proof-Of-Space Approaches for Permissionless Blockchains

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Efficient Proof-Of-Space Approaches for Permissionless Blockchains Efficient Proof-of-Space approaches for permissionless blockchains Jo~aoVasco Estrela Martinho [email protected] Instituto Superior T´ecnico Advisors: Prof. Miguel Matos Prof. Jo~aoBarreto Abstract. Bicoin, one of the most famous blockchains in the world, relies on Proof- of-Work to solve the distributed ledger problem. Proof-of-Work however is not ideal for its high energy consumption and overall high confirmation times. Alternatives such as Proof-of-Stake and Proof-of-Space promise better sustainability and scalabil- ity but introduce problems such as the nothing-at-stake issue. Therefore, they need to be combined with other mechanisms that counter these problems. Existing ap- proaches rely on ad-hoc mechanisms, such as Proof-of-Work itself, and thus have several theoretical and practical shortcomings. In this thesis, we propose AstroChain, a permissionless Proof-of-Space blockchain that uses a reconfigurable random generator protocol to ensure liveness and safety of the system. By simply relying on message passing to ensure security, AstroChain has lower energetic costs than Proof-of-Work blockchains and has the potential to offer high throughput and low confirmation times for transactions, which makes the blockchain more useful and sustainable. Table of Contents 1 Introduction . .3 2 Related Work . .5 2.1 Distributed Ledgers and Blockchains . .5 2.2 Bitcoin . .7 2.3 Alternatives to Bitcoin . .9 2.4 Random Beacons in Blockchains. 15 2.5 Discussion . 15 3 AstroChain . 17 3.1 Proof chain . 18 3.2 Random chain . 18 3.3 Transaction chain . 20 3.4 Vulnerabilities and solutions . 21 3.5 Discussion . 21 4 Evaluation . 22 5 Schedule of Future Work . 22 6 Conclusion . 23 1 Introduction Blockchains have become increasingly more popular in the last years, especially since the appearance of Bitcoin [1] in 2009. A blockchain is a distributed system that implements a ledger. A ledger is a record of transactions from one entity to another. A ledger has the property of only allowing for transactions to be appended sequentially and, once in the ledger, may not be changed. This way, order is secured and any change to previously stored transactions makes the ledger invalid. A ledger is then a "full picture" of the assets held by each entity. The importance of blockchains comes from the fact that, using them, we can build a decentralized application where there are few trust assumptions and possibly a large number of processes are allowed to participate. In a lot of distributed systems nowadays, such as banking systems, for example, there exists a central third party on which the system relies, and thus, we must trust this entity for the system to work. This may be undesirable, since, should this central entity fail, the whole system breaks down. As such, permissionless blockchains were proposed to build a fully decentralized distributed system, where no single central entity exists, but multiple entities work together in a protocol that allows participants to not trust each other, but still trust the protocol itself. In doing this, if a single entity fails, the system still works as expected. Most blockchains nowadays (such as Bitcoin) are used to implement cryptocurrencies. By using blockchains to implement this virtual currency, a user can transfer to others without needing to trust a centralized third-party (in contrast to traditional banking systems). An- other useful application of blockchains is smart contracts, first deployed in the Ethereum [2] blockchain. In this approach, transactions are not currency transfers, but executable pieces of code (contracts) that are executed by users. The validation of these executions is done and agreed upon by blockchain users, thus allowing for the construction of fully decentralized applications. The most prevalent way of implementing blockchains follows a variant of what is called the Nakamoto Consensus, first introduced in Bitcoin [1]. The three main components of Nakamoto consensus are incentives, a chain selection rule, and Proof-of-Work. Proof-of-Work is a cryptographic puzzle that a participant must solve to add a block to the blockchain. To solve the puzzle, the participants must use a non-counterfeitable resource, in this case, computational power. This mechanism is used to prevent what is called Sybil attacks, which can be described as a single user voting as if they are multiple participants. This is not enough to ensure the validity of the chain, as two different participants may be able to solve the puzzle at similar times. At this point, what is called a fork may occur, where two valid views of the blockchain coexist. To prevent this, the chain selection rule tells us which chain to select based on the blocks we see. Finally, incentives are rewards given to participants that follow the protocol. This way, new participants are attracted to join the system, which will increase the security of the blockchain. Incentives also work to discourage malicious participants from breaking protocol. When a participant breaks protocol, it might not receive incentives, but still wasted the non-counterfeitable resource, which is wasteful for the malicious participant. However, Proof-of-Work has some important problems. Firstly, it uses up a lot of energy and thus is very wasteful. Currently, the energetic footprint of adding a transaction to Bitcoin and Ethereum, the two most famous blockchains that use Proof-of-Work, is equivalent to respectively 24 and 1 days worth of energy consumption of the average US household [3,4]. Another known issue of Proof-of-Work is its efficiency. For a blockchain to be fully useful, 3 it is required for there to be a low processing time for transactions. However, Proof-of- Work usually introduces low throughput and long confirmation times for transactions. This is because the puzzles in Proof-of-Work need to take some amount of time to be solved and each block cannot contain a high number of transactions, otherwise, the security of the system is not guaranteed. On top of that, the transactions need to be some blocks deep to be probabilistically trusted, due to forks. Only after being a few blocks deep, can transactions be trusted to be stable with high probability. Because of this, several proposals have appeared to build upon Proof-of-Work to solve these known issues [5,6,7]. A general idea to reduce the energy costs per transaction of Proof-of-Work is to parallelize the transaction handling and puzzle solving, which allows for higher transaction throughput and confirmation times, as well as reducing the difficulty of the puzzles, which decreases the energetic costs, as well as allowing for faster progress of the system. Proof-of-Work approaches in general still have large energetic costs and impractical trans- action handling, which becomes unsustainable and undesirable for the future of blockchains. As such, it is important to come up with blockchain approaches that replace Proof-of-Work as the central security enforcing mechanism. One interesting approach to blockchains that appeared was Algorand [8]. It used the well- known notion of Byzantine Agreement to solve the distributed ledger problem. Usually, this would be complicated, as Byzantine Agreement protocols have a scalability issue. Algorand however randomly selects from all participants a small set of processes, which acts as a committee that decides blocks to be added. In doing so, transaction handling is much faster and security is still preserved. Other systems to prevent Sybil attacks have also been appearing, to replace Proof-of- Work and its limitations in Nakamoto consensus. One example is Proof-of-Stake, which uses the amount of currency a participant holds in the system (stake) as the non-counterfeitable resource. For a user to add a block, they must stake their money and, the higher their stake is, the higher their chance of successfully adding a block to the chain. Another example is Proof-of-Elapsed-Time, where participants make use of a Trusted Execution Environment, a safe space in memory that no malicious process can tamper with, to run a lottery that will choose who adds the next block to the chain. Another approach to prevent Sybil attacks is Proof-of-Space. In this approach, the non- counterfeitable resource is memory or disk space. Usually, before being able to mine, a participant reserves some (non-trivial) amount of memory and dedicates it to the system, filling it with data. When trying to add a block to the chain, the participant resorts to this reserved space to generate the solution to the puzzle. This approach has the potential of making Nakamoto Consensus more energy and time-efficient, as the solution to the puzzle can be approximated to some memory accesses. Proof-of-Space has a known issue though: the proof generation is very fast. This creates the nothing-at-stake problem, that is, a participant can generate a lot of alternative blocks with a residual cost. It matters to note that this problem is not present in Proof-of-Work, since generating a block is expensive and therefore not worth it to mine multiple different blocks unless there is a relatively high degree of certainty in the success of the attack. Spacemint [9] was a Proof-of-Space proposal that tried to prevent nothing-at-stake by penalizing the participants that were found to try to mine multiple blocks for the same height. This however does not fully prevent the problem, because a miner may easily generate a sequence of blocks in private, with close to no cost, and thus, when they propose this new chain, no illegal behavior is detected. Another Proof-of-Space approach is Chia [10], where 4 they use Verifiable Delay Functions to prevent miners from creating long sequences of blocks without sacrificing any resource.
Load more

Recommended publications
  • Chia Proof of Space Construction
    Chia Proof of Space Construction Introduction In order to create a secure blockchain consensus algorithm using disk space, a Proof of Space is scheme is necessary. This document describes a practical contruction of Proofs of Space, based on Beyond Hellman’s Time- Memory Trade-Offs with Applications to Proofs of Space [1]. We use the techniques laid out in that paper, extend it from 2 to 7 tables, and tweak it to make it efficient and secure, for use in the Chia Blockchain. The document is divided into three main sections: What (mathematical definition of a proof of space), How (how to implement proof of space), and Why (motivation and explanation of the construction) sections. The Beyond Hellman paper can be read first for more mathematical background. Chia Proof of Space Construction Introduction What is Proof of Space? Definitions Proof format Proof Quality String Definition of parameters, and M, f, A, C functions: Parameters: f functions: Matching function M: A′ function: At function: Collation function C: How do we implement Proof of Space? Plotting Plotting Tables (Concepts) Tables Table Positions Compressing Entry Data Delta Format ANS Encoding of Delta Formatted Points Stub and Small Deltas Parks Checkpoint Tables Plotting Algorithm Final Disk Format Full algorithm Phase 1: Forward Propagation Phase 2: Backpropagation Phase 3: Compression Phase 4: Checkpoints Sort on Disk Plotting Performance Space Required Proving Proof ordering vs Plot ordering Proof Retrieval Quality String Retrieval Proving Performance Verification Construction
    [Show full text]
  • IPFS and Friends: a Qualitative Comparison of Next Generation Peer-To-Peer Data Networks Erik Daniel and Florian Tschorsch
    1 IPFS and Friends: A Qualitative Comparison of Next Generation Peer-to-Peer Data Networks Erik Daniel and Florian Tschorsch Abstract—Decentralized, distributed storage offers a way to types of files [1]. Napster and Gnutella marked the beginning reduce the impact of data silos as often fostered by centralized and were followed by many other P2P networks focusing on cloud storage. While the intentions of this trend are not new, the specialized application areas or novel network structures. For topic gained traction due to technological advancements, most notably blockchain networks. As a consequence, we observe that example, Freenet [2] realizes anonymous storage and retrieval. a new generation of peer-to-peer data networks emerges. In this Chord [3], CAN [4], and Pastry [5] provide protocols to survey paper, we therefore provide a technical overview of the maintain a structured overlay network topology. In particular, next generation data networks. We use select data networks to BitTorrent [6] received a lot of attention from both users and introduce general concepts and to emphasize new developments. the research community. BitTorrent introduced an incentive Specifically, we provide a deeper outline of the Interplanetary File System and a general overview of Swarm, the Hypercore Pro- mechanism to achieve Pareto efficiency, trying to improve tocol, SAFE, Storj, and Arweave. We identify common building network utilization achieving a higher level of robustness. We blocks and provide a qualitative comparison. From the overview, consider networks such as Napster, Gnutella, Freenet, BitTor- we derive future challenges and research goals concerning data rent, and many more as first generation P2P data networks, networks.
    [Show full text]
  • Evaluating Inclusion, Equality, Security, and Privacy in Pseudonym Parties and Other Proofs of Personhood
    Identity and Personhood in Digital Democracy: Evaluating Inclusion, Equality, Security, and Privacy in Pseudonym Parties and Other Proofs of Personhood Bryan Ford Swiss Federal Institute of Technology in Lausanne (EPFL) November 5, 2020 Abstract of enforced physical security and privacy can address the coercion and vote-buying risks that plague today’s E- Digital identity seems at first like a prerequisite for digi- voting and postal voting systems alike. We also examine tal democracy: how can we ensure “one person, one vote” other recently-proposed approaches to proof of person- online without identifying voters? But the full gamut of hood, some of which offer conveniencessuch as all-online digital identity solutions – e.g., online ID checking, bio- participation. These alternatives currently fall short of sat- metrics, self-sovereign identity, and social/trust networks isfying all the key digital personhood goals, unfortunately, – all present severe flaws in security, privacy, and trans- but offer valuable insights into the challenges we face. parency, leaving users vulnerable to exclusion, identity loss or theft, and coercion. These flaws may be insur- mountable because digital identity is a cart pulling the Contents horse. We cannot achieve digital identity secure enough to support the weight of digital democracy, until we can 1 Introduction 2 build it on a solid foundation of digital personhood meet- ing key requirements. While identity is about distinguish- 2 Goals for Digital Personhood 4 ing one person from another through attributes or affilia- tions, personhood is about giving all real people inalien- 3 Pseudonym Parties 5 able digital participation rights independent of identity, 3.1 Thebasicidea.
    [Show full text]
  • Asymmetric Proof-Of-Work Based on the Generalized Birthday Problem
    Equihash: Asymmetric Proof-of-Work Based on the Generalized Birthday Problem Alex Biryukov Dmitry Khovratovich University of Luxembourg University of Luxembourg [email protected] [email protected] Abstract—The proof-of-work is a central concept in modern Long before the rise of Bitcoin it was realized [20] that cryptocurrencies and denial-of-service protection tools, but the the dedicated hardware can produce a proof-of-work much requirement for fast verification so far made it an easy prey for faster and cheaper than a regular desktop or laptop. Thus the GPU-, ASIC-, and botnet-equipped users. The attempts to rely on users equipped with such hardware have an advantage over memory-intensive computations in order to remedy the disparity others, which eventually led the Bitcoin mining to concentrate between architectures have resulted in slow or broken schemes. in a few hardware farms of enormous size and high electricity In this paper we solve this open problem and show how to consumption. An advantage of the same order of magnitude construct an asymmetric proof-of-work (PoW) based on a compu- is given to “owners” of large botnets, which nowadays often tationally hard problem, which requires a lot of memory to gen- accommodate hundreds of thousands of machines. For prac- erate a proof (called ”memory-hardness” feature) but is instant tical DoS protection, this means that the early TLS puzzle to verify. Our primary proposal Equihash is a PoW based on the schemes [8], [17] are no longer effective against the most generalized birthday problem and enhanced Wagner’s algorithm powerful adversaries.
    [Show full text]
  • A Survey of Distributed Consensus Protocols for Blockchain Networks
    1 A Survey of Distributed Consensus Protocols for Blockchain Networks Yang Xiao∗, Ning Zhang†, Wenjing Lou∗, Y. Thomas Hou∗ ∗Virginia Polytechnic Institute and State University, VA, USA †Washington University in St. Louis, MO, USA Abstract—Since the inception of Bitcoin, cryptocurrencies participants. On the other hand, blockchain is also known for and the underlying blockchain technology have attracted an providing trustworthy immutable record keeping service. The increasing interest from both academia and industry. Among block data structure adopted in a blockchain embeds the hash various core components, consensus protocol is the defining technology behind the security and performance of blockchain. of the previous block in the next block generated. The use of From incremental modifications of Nakamoto consensus protocol hash chain ensures that data written on the blockchain can not to innovative alternative consensus mechanisms, many consensus be modified. In addition, a public blockchain system supports protocols have been proposed to improve the performance of third-party auditing and some blockchain systems support a the blockchain network itself or to accommodate other specific high level of anonymity, that is, a user can transact online application needs. In this survey, we present a comprehensive review and anal- using a pseudonym without revealing his/her true identity. ysis on the state-of-the-art blockchain consensus protocols. To The security properties promised by blockchain is unprece- facilitate the discussion of our analysis, we first introduce the dented and truly inspiring. Pioneering blockchain systems such key definitions and relevant results in the classic theory of fault as Bitcoin have greatly impacted the digital payment world.
    [Show full text]
  • A Survey on Consensus Mechanisms and Mining Strategy Management
    1 A Survey on Consensus Mechanisms and Mining Strategy Management in Blockchain Networks Wenbo Wang, Member, IEEE, Dinh Thai Hoang, Member, IEEE, Peizhao Hu, Member, IEEE, Zehui Xiong, Student Member, IEEE, Dusit Niyato, Fellow, IEEE, Ping Wang, Senior Member, IEEE Yonggang Wen, Senior Member, IEEE and Dong In Kim, Fellow, IEEE Abstract—The past decade has witnessed the rapid evolution digital tokens between Peer-to-Peer (P2P) users. Blockchain in blockchain technologies, which has attracted tremendous networks, especially those adopting open-access policies, are interests from both the research communities and industries. The distinguished by their inherent characteristics of disinterme- blockchain network was originated from the Internet financial sector as a decentralized, immutable ledger system for transac- diation, public accessibility of network functionalities (e.g., tional data ordering. Nowadays, it is envisioned as a powerful data transparency) and tamper-resilience [2]. Therefore, they backbone/framework for decentralized data processing and data- have been hailed as the foundation of various spotlight Fin- driven self-organization in flat, open-access networks. In partic- Tech applications that impose critical requirement on data ular, the plausible characteristics of decentralization, immutabil- security and integrity (e.g., cryptocurrencies [3], [4]). Further- ity and self-organization are primarily owing to the unique decentralized consensus mechanisms introduced by blockchain more, with the distributed consensus provided by blockchain networks. This survey is motivated by the lack of a comprehensive networks, blockchains are fundamental to orchestrating the literature review on the development of decentralized consensus global state machine1 for general-purpose bytecode execution. mechanisms in blockchain networks. In this survey, we provide a Therefore, blockchains are also envisaged as the backbone systematic vision of the organization of blockchain networks.
    [Show full text]
  • Proof of Behavior Paul-Marie Grollemund, Pascal Lafourcade, Kevin Thiry-Atighehchi, Ariane Tichit
    Proof of Behavior Paul-Marie Grollemund, Pascal Lafourcade, Kevin Thiry-Atighehchi, Ariane Tichit To cite this version: Paul-Marie Grollemund, Pascal Lafourcade, Kevin Thiry-Atighehchi, Ariane Tichit. Proof of Behav- ior. The 2nd Tokenomics Conference on Blockchain Economics, Security and Protocols, Oct 2020, Toulouse, France. hal-02559573 HAL Id: hal-02559573 https://hal.archives-ouvertes.fr/hal-02559573 Submitted on 30 Apr 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License 1 Proof of Behavior 2 Paul-Marie Grollemund 3 Université Clermont Auvergne, LMBP UMR 6620, Aubière, France 4 [email protected] 1 5 Pascal Lafourcade 6 Université Clermont Auvergne, LIMOS UMR 6158, Aubière, France 7 [email protected] 8 Kevin Thiry-Atighehchi 9 Université Clermont Auvergne, LIMOS UMR 6158, Aubière, France 10 [email protected] 11 Ariane Tichit 12 Université Clermont Auvergne, Cerdi UMR 6587, Clermont-Ferrand France 13 [email protected] 14 Abstract 15 Our aim is to change the Proof of Work paradigm. Instead of wasting energy in dummy computations 16 with hash computations, we propose a new approach based on the behavior of the users.
    [Show full text]
  • Blockchain-Based Secure Storage Management with Edge Computing for Iot
    Article Blockchain-Based Secure Storage Management with Edge Computing for IoT Baraka William Nyamtiga 1, Jose Costa Sapalo Sicato 2, Shailendra Rathore 2, Yunsick Sung 3 and Jong Hyuk Park 2,* 1 Department of Electrical and Information Engineering, Seoul National University of Science and Technology, Seoul 01811, Korea 2 Department of Computer Science and Engineering, Seoul National University of Science and Technology, Seoul 01811, Korea 3 Department of Multimedia Engineering, Dongguk University-Seoul, Seoul 04620, Korea * Correspondence: [email protected]; Tel.: +82-2-970-6702 Received: 27 May 2019; Accepted: 21 July 2019; Published: 25 July 2019 Abstract: As a core technology to manage decentralized systems, blockchain is gaining much popularity to deploy such applications as smart grid and healthcare systems. However, its utilization in resource-constrained mobile devices is limited due to high demands of resources and poor scalability with frequent-intensive transactions. Edge computing can be integrated to facilitate mobile devices in offloading their mining tasks to cloud resources. This integration ensures reliable access, distributed computation and untampered storage for scalable and secure transactions. It is imperative therefore that crucial issues of security, scalability and resources management be addressed to achieve successful integration. Studies have been conducted to explore suitable architectural requirements, and some researchers have applied the integration to deploy some specific applications. Despite these efforts, however, issues of anonymity, adaptability and integrity still need to be investigated further to attain a practical, secure decentralized data storage. We based our study on peer-to-peer and blockchain to achieve an Internet of Things (IoT) design supported by edge computing to acquire security and scalability levels needed for the integration.
    [Show full text]
  • On the Viability of Distributed Consensus by Proof of Space
    On the Viability of Distributed Consensus by Proof of Space Vivek Bhupatiraju John Kuszmaul Vinjai Vale March 3, 2017 Abstract In this paper, we present our implementation of Proof of Space (PoS) and our study of its viabil- ity in distributed consensus. PoS is a new alternative to the commonly used Proof of Work, which is a protocol at the heart of distributed consensus systems such as Bitcoin. PoS resolves the two major drawbacks of Proof of Work: high energy cost and bias towards individuals with special- ized hardware. In PoS, users must store large “hard-to-pebble” PTC graphs, which are recursively generated using subgraphs called superconcentrators. We implemented two types of superconcen- trators to examine their differences in performance. Linear superconcentrators are about 1:8 times slower than butterfly superconcentrators, but provide a better lower bound on space consumption. Finally, we discuss our simulation of using PoS to reach consensus in a peer-to-peer network. We conclude that Proof of Space is indeed viable for distributed consensus. To the best of our knowledge, we are the first to implement linear superconcentrators and to simulate the use of PoS to reach consensus on a decentralized network. 1 Introduction and Motivation Proof of Space [2] is a new and promising cryptographic primitive. One of its most important potential applications lies in distributed consensus on a decentralized network, which is essential for cryptocurrencies such as Bitcoin. This paper demonstrates experimentally that Proof of Space is effective in this context, and provides the first performance analysis for its use to reach consensus.
    [Show full text]
  • Koppercoin – a Distributed File Storage with Financial Incentives
    KopperCoin – A Distributed File Storage with Financial Incentives B Henning Kopp( ), Christoph B¨osch, and Frank Kargl Institute of Distributed Systems, Ulm University, Ulm, Germany {henning.kopp,christoph.boesch,frank.kargl}@uni-ulm.de Abstract. One of the current problems of peer-to-peer-based file stor- age systems like Freenet is missing participation, especially of storage providers. Users are expected to contribute storage resources but may have little incentive to do so. In this paper we propose KopperCoin, a token system inspired by Bitcoin’s blockchain which can be integrated into a peer-to-peer file storage system. In contrast to Bitcoin, Kopper- Coin does not rely on a proof of work (PoW) but instead on a proof of retrievability (PoR). Thus it is not computationally expensive and instead requires participants to contribute file storage to maintain the network. Participants can earn digital tokens by providing storage to other users, and by allowing other participants in the network to down- load files. These tokens serve as a payment mechanism. Thus we provide direct reward to participants contributing storage resources. Keywords: Blockchain · Cloud storage · Cryptocurrency · Peer-to-peer · Proof of retrievability 1 Introduction In recent years, cryptocurrencies have rapidly gained adoption. One of the pio- neers and most successful e-cash system is Bitcoin [17], in which clients, called miners, invest computational power to create units of a virtual currency. This process of generating Bitcoins is called mining. Bitcoin’s mining process consists in finding a pre-image of a hash function such that the resulting hash is small. This is done via brute-forcing which may be seen as a waste of computing power and ultimately energy.
    [Show full text]
  • Crypto Jacking a Technique to Leverage Technology to Mine Crypto Currency
    International Journal of Academic Research in Business and Social Sciences Vol. 9 , No. 3, March, 2019,E-ISSN:2222-6990 © 2019 HRMARS Crypto Jacking a Technique to Leverage Technology to Mine Crypto Currency Haitham Hilal Al Hajri, Badar Mohammed Al Mughairi, Mohammad Imtiaz Hossain, Asif Mahbub Karim To Link this Article: http://dx.doi.org/10.6007/IJARBSS/v9-i3/5791 DOI: 10.6007/IJARBSS/v9-i3/5791 Received: 01 Feb 2019, Revised: 17 Feb 2019, Accepted: 29 Feb 2019 Published Online: 04 March 2019 In-Text Citation:(Hajri, Mughairi, Hossain, & Karim, 2019) To Cite this Article: Hajri, H. H. Al, Mughairi, B. M. Al, Hossain, M. I., & Karim, A. M. (2019). Crypto Jacking a Technique to Leverage Technology to Mine Crypto Currency. International Journal Academic Research Business and Social Sciences, 9(3), 1220–1231. Copyright: © 2019The Author(s) Published by Human Resource Management Academic Research Society (www.hrmars.com) This article is published under the Creative Commons Attribution (CC BY 4.0) license. Anyone may reproduce, distribute, translate and create derivative works of this article (for both commercial and non-commercial purposes), subject to full attribution to the original publication and authors. The full terms of this license may be seen at: http://creativecommons.org/licences/by/4.0/legalcode Vol. 9, No. 3, 2019, Pg. 1220 - 1231 http://hrmars.com/index.php/pages/detail/IJARBSS JOURNAL HOMEPAGE Full Terms & Conditions of access and use can be found athttp://hrmars.com/index.php/pages/detail/publication-ethics 1220 International Journal of Academic Research in Business and Social Sciences Vol.
    [Show full text]
  • Proof of Work and Proof of Stake Consensus Protocols: a Blockchain Application for Local Complementary Currencies
    Proof of Work and Proof of Stake consensus protocols: a blockchain application for local complementary currencies Sothearath SEANG∗ Dominique TORRE∗ February 2018 Abstract This paper examines with the help of a theoretical setting the proper- ties of two blockchains' consensus protocols (Proof of Work and Proof of Stake) in the management of a local (or networks of local) complementary currency(ies). The model includes the control by the issuer of advantages of the use of the currency by heterogeneous consumers, and the determination of rewards of also heterogeneous validators (or miners). It considers also the resilience of the validation protocols to malicious attacks conducted by an individual or pools of validators. Results exhibit the interest of the Proof of Stake protocol for small communities of users of the complementary cur- rency, despite the Proof of Work Bitcoin like system could have advantages when the size of the community increases. JEL Classification: E42, L86 Keywords: payment systems, heterogeneous agents, Proof of Work, Proof of Stake, blockchains, complementary currencies. 1 Introduction In recent years, the blockchain technology (BCT) has sparked a lot of interest around the world and its applications are being tested across many sectors such as ∗Universit´eC^oted'Azur - GREDEG - CNRS, 250 rue Albert Einstein, 06560 Valbonne, France. E-mails: [email protected], [email protected] 1 finance, energy, public services and sharing platforms. Although the technology is still immature and going through numerous experiments, the potentially diverse benefits and opportunities derived from its decentralised and open-to-innovation nature have drawn much attention from researchers and investors.
    [Show full text]