A Taxonomy of Blockchain Consensus Methods
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IOTA: a Cryptographic Perspective
IOTA: A Cryptographic Perspective Bryan Baek Jason Lin Harvard University Georgia Institute of Technology [email protected] [email protected] 1 Introduction IOTA is an open-source distributed ledger protocol that presents a unique juxtaposition to the blockchain-based Bitcoin. Instead of using the traditional blockchain approach, IOTA stores individual transactions in a directed-acyclic graph (DAG) called Tangle. IOTA claims that this allows several benefits over its blockchain-based predecessors such as quantum-proof properties, no transaction fees, fast transactions, secure data transfer, and infinite scalability. Currently standing at 16th place in the CoinMarketCap, it topped 7 during the height of the bullish period of late 2017. Given these claims and attractions, this paper seeks to analyze the benefits and how they create vulnerabilities and/or disadvantages compared to the standard blockchain approach. Based upon our findings, we will discuss the future of IOTA and its potential of being a viable competitor to blockchain technology for transactions. 2 Background IOTA, which stands for Internet of Things Application [1], is a crypto technology in the form of a distributed ledger that facilitates transactions between Internet of Things (IoT) devices. IoT encompass smart home devices, cameras, sensors, and other devices that monitor conditions in commercial, industrial, and domestic settings [2]. As IoT becomes integrated with different facets of our life, their computational power and storage is often left to waste when idle. David Sonstebo, Sergey Ivancheglo, Dominik Schiener, and Serguei Popov founded the IOTA Foundation in June 2015 after working in the IoT industry because they saw the need to create an ecosystem where IoT devices share and allocate resources efficiently [3]. -
Wallance, an Alternative to Blockchain for Iot Loïc Dalmasso, Florent Bruguier, Achraf Lamlih, Pascal Benoit
Wallance, an Alternative to Blockchain for IoT Loïc Dalmasso, Florent Bruguier, Achraf Lamlih, Pascal Benoit To cite this version: Loïc Dalmasso, Florent Bruguier, Achraf Lamlih, Pascal Benoit. Wallance, an Alternative to Blockchain for IoT. IEEE 6th World Forum on Internet of Things (WF-IoT 2020), Jun 2020, New Orleans, LA, United States. 10.1109/WF-IoT48130.2020.9221474. hal-02893953v2 HAL Id: hal-02893953 https://hal.archives-ouvertes.fr/hal-02893953v2 Submitted on 1 Oct 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. Wallance, an Alternative to Blockchain for IoT Loïc Dalmasso, Florent Bruguier, Achraf Lamlih, Pascal Benoit LIRMM University of Montpellier, CNRS Montpellier, France [email protected] Abstract—Since the expansion of the Internet of Things a decentralized Machine-to-Machine (M2M) communication (IoT), connected devices became smart and autonomous. Their protocol. A security mechanism has to ensure the trust exponentially increasing number and their use in many between devices, securing all interactions without a central application domains result in a huge potential of cybersecurity authority like Cloud. In this context, the blockchain system threats. Taking into account the evolution of the IoT, security brings many benefits in terms of reliability and security. -
Blockchain in the Integrated Energy Transition
dena MULTI-STAKEHOLDER STUDY Blockchain in the integrated energy transition Study findings (dena) Blockchain in the integrated energy transition energy in the integrated Blockchain dena MULTI-STAKEHOLDER STUDY STUDY dena MULTI-STAKEHOLDER Legal information Publisher: All content has been prepared with the greatest possible care Deutsche Energie-Agentur GmbH (dena) and is provided in good faith. dena provides no guarantee for German Energy Agency the currency, accuracy, or completeness of the information Chausseestrasse 128 a provided. dena shall not be liable for damages of a material 10115 Berlin, Germany or intangible nature resulting from the use or non-use of the Tel.: + 49 (0)30 66 777-0 information provided, whether indirectly or directly, unless Fax: + 49 (0)30 66 777-699 proof of intentional or grossly negligent culpability on its part www.dena.de is provided. Authors: All rights reserved. Consent from dena is required for any use. Philipp Richard (dena) Sara Mamel (dena) Lukas Vogel (dena) Scientific experts: Prof. Dr. Jens Strüker (INEWI) Dr. Ludwig Einhellig (Deloitte) Last updated: 02/2019 Conception & design: Heimrich & Hannot GmbH Content Foreword 4 Executive summary 6 The dena multi-stakeholder study “Blockchain in the integrated energy transition” 6 Recommended courses of action 8 Checklist for blockchain in the integrated energy transition 10 Technical findings 12 Economic findings 14 Regulatory findings 17 1 Blockchain in the integrated energy transition 20 2 Blockchain technology: status quo and development prospects -
Chapter 1 from Byzantine Consensus to Blockchain Consensus
Chapter 1 From Byzantine Consensus to Blockchain Consensus CONTENTS 1.1 Introduction ....................................................... 3 1.2 Byzantine Consensus .............................................. 6 1.2.1 On System Models ........................................ 6 1.2.2 Byzantine Consensus Definitions .......................... 7 1.2.3 FLP Impossibility ......................................... 9 1.2.4 Byzantine Consensus Patterns ............................. 12 1.2.5 Hybrid Models to Reduce Processes ....................... 13 1.2.6 Randomization ............................................ 15 1.3 Blockchains with Nakamoto Consensus ............................. 19 1.3.1 Bitcoin’s Blockchain and Consensus ....................... 19 1.3.2 Blockchain Applications ................................... 24 1.3.3 Nakamoto Consensus Variants ............................. 27 1.4 Blockchains with Byzantine Consensus ............................. 30 1.4.1 Permissioned Blockchains with Byzantine Consensus ....... 30 1.4.2 Permissionless Blockchains with Hybrid Consensus ........ 32 1.5 Conclusion ........................................................ 34 3 4 ⌅ Saunders Template 1.1 Introduction Blockchain is an exciting new technology that is making headlines worldwide. The reasons behind the success of a technology are often unclear, but in the case of block- chain it is safe to say that an important factor is that is has two killer apps, not a single one. The first killer app are cryptocurrencies, as the original blockchain is the core of Bitcoin [128], the first cryptocurrency and the one that is fostering the adoption of cryptocurrencies. The second killer app are smart contracts, first introduced in the Ethereum system [40], with their promise of computerizing legal contracts and of supporting a countless number of applications [161, 153, 90]. Moreover, the sky seems to be the limit for the applications people are imagining for blockchain. A blockchain is essentially a secure, unmodifiable, append-only, log of transac- tions. -
Cryptocurrency Speculation and Blockchain Stocks (December 16, 2017 by Dafang Wu; PDF Version)
Cryptocurrency Speculation and Blockchain Stocks (December 16, 2017 by Dafang Wu; PDF Version) After Chicago Board Options Exchange began transactions of Bitcoin future contracts last week, cryptocurrency (“coin”) is becoming mainstream. We are quite late to this game, as many coins have appreciated more than 100 times so far this year, but it is never too late. This situation is similar to the early era of internet development, so we will need to understand the situation and cautiously catch up. Similar to many articles I wrote on airport finance, this article provides information rather than recommendations. Many coins are almost scams; many publicly traded companies claiming to be in blockchain technology, especially those traded over-the-counter (OTC), are also scams. Therefore, further research is required to make investment decisions, if we call coin speculation an “investment.” Background Instead of discussing the history of coins or technology, here are the basics that we need to know: Coins are digital currencies issued by organizations or teams; ownership and transactions are recorded in a public ledger There are more than 1,000 coins, with Bitcoin having the highest market capitalization of nearly $300 billion Each coin has a name, such as Bitcoin, and a trading ticker like stock, such as BTC There are more than 7,000 coin exchanges Some exchanges allow us to purchase coins using real life money, which they refer to as fiat money Some exchanges are not regulated, and only allow us to trade among coins. For this type of exchange, Bitcoin is typically the currency. To switch between two other coins, we will need to sell the first one and receive Bitcoin, and use the Bitcoin to purchase the second one There is no customer service for any coin – if we accidentally lose it or send to a wrong party, there is no way to get back Security threat and fraud always exist for coin trading – search Mt. -
Beauty Is Not in the Eye of the Beholder
Insight Consumer and Wealth Management Digital Assets: Beauty Is Not in the Eye of the Beholder Parsing the Beauty from the Beast. Investment Strategy Group | June 2021 Sharmin Mossavar-Rahmani Chief Investment Officer Investment Strategy Group Goldman Sachs The co-authors give special thanks to: Farshid Asl Managing Director Matheus Dibo Shahz Khatri Vice President Vice President Brett Nelson Managing Director Michael Murdoch Vice President Jakub Duda Shep Moore-Berg Harm Zebregs Vice President Vice President Vice President Shivani Gupta Analyst Oussama Fatri Yousra Zerouali Vice President Analyst ISG material represents the views of ISG in Consumer and Wealth Management (“CWM”) of GS. It is not financial research or a product of GS Global Investment Research (“GIR”) and may vary significantly from those expressed by individual portfolio management teams within CWM, or other groups at Goldman Sachs. 2021 INSIGHT Dear Clients, There has been enormous change in the world of cryptocurrencies and blockchain technology since we first wrote about it in 2017. The number of cryptocurrencies has increased from about 2,000, with a market capitalization of over $200 billion in late 2017, to over 8,000, with a market capitalization of about $1.6 trillion. For context, the market capitalization of global equities is about $110 trillion, that of the S&P 500 stocks is $35 trillion and that of US Treasuries is $22 trillion. Reported trading volume in cryptocurrencies, as represented by the two largest cryptocurrencies by market capitalization, has increased sixfold, from an estimated $6.8 billion per day in late 2017 to $48.6 billion per day in May 2021.1 This data is based on what is called “clean data” from Coin Metrics; the total reported trading volume is significantly higher, but much of it is artificially inflated.2,3 For context, trading volume on US equity exchanges doubled over the same period. -
DFINITY Technology Overview Series Consensus System
DFINITY Technology Overview Series Consensus System Rev.1 Timo Hanke, Mahnush Movahedi and Dominic Williams ABSTRACT Dfinity will be introduced in a series of technology overviews, The Dfinity blockchain computer provides a secure, performant each highlighting an independent innovation in Dfinity such as and flexible consensus mechanism. While first defined for a permis- the consensus backbone, smart contract language, virtual machine, sioned participation model, the consensus mechanism itself can be concurrent contract execution model, daemon contracts, peer-to- paired with any method of Sybil resistance (e.g. proof-of-work or peer networks and secure broadcast, governance mechanism and proof-of-stake) to create an open participation model. Dfinity’s scaling techniques. The present document will focus on the con- greatest strength is unfolded in the most challenging proof-of-stake sensus backbone and cryptographic randomness. case. Dfinity has an unbiasable, verifiable random function (VRF) At its core, Dfinity contains a decentralized randomness beacon built-in at the core of its protocol. The VRF not only drives the which acts as a verifiable random function (VRF) that produces a consensus, it will also be the foundation for scaling techniques such stream of outputs over time. The novel technique behind the beacon as sharding, validation towers, etc. Moreover, the VRF produced relies on the existence of a unique-deterministic, non-interactive, by the consensus layer is available to the application layer, i.e., to DKG-friendly threshold signatures scheme. The only known ex- the smart contracts and virtual machine. In this way, the consensus amples of such a scheme are pairing-based and derived from BLS backbone is intertwined with many of the other topics. -
Initial Crypto-Asset Offerings (Icos), Tokenization and Corporate Governance Stéphane Blémus, Dominique Guegan
Initial Crypto-asset Offerings (ICOs), tokenization and corporate governance Stéphane Blémus, Dominique Guegan To cite this version: Stéphane Blémus, Dominique Guegan. Initial Crypto-asset Offerings (ICOs), tokenization and corpo- rate governance. 2019. halshs-02079171 HAL Id: halshs-02079171 https://halshs.archives-ouvertes.fr/halshs-02079171 Submitted on 25 Mar 2019 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. Documents de Travail du Centre d’Economie de la Sorbonne Initial Crypto-asset Offerings (ICOs), tokenization and corporate governance Stéphane BLEMUS, Dominique GUEGAN 2019.04 Maison des Sciences Économiques, 106-112 boulevard de L'Hôpital, 75647 Paris Cedex 13 https://centredeconomiesorbonne.univ-paris1.fr/ ISSN : 1955-611X Initial Crypto-asset Offerings (ICOs), tokenization and corporate governance Stéphane Blemus* & Dominique Guégan** * Paris 1 Panthéon-Sorbonne University, LabEx ReFi, Kalexius law firm, ChainTech ** Centre d’Economie de la Sorbonne, Paris 1 Panthéon-Sorbonne University, Labex ReFi, Ca’Foscari University, Venezia, IPAG Business School This interdisciplinary paper by a mathematician and a legal counsel, both from the Paris 1 Panthéon-Sorbonne University, discusses the potential impacts of the so-called “initial coin offerings”, and of several developments based on distributed ledger technology (“DLT”), on corporate governance. -
The Convergence Ecosystem
The Convergence Ecosystem Convergence 2.0 Building the Decentralised Future This document (the “Document”) has been prepared by Outlier Ventures Operations Disclaimer Limited (“Outlier Ventures”). Outlier Ventures Operations Ltd is registered in England and Wales, company registration number 10722638. Outlier Ventures Operations Ltd is an appointed representative of Sapia Partners LLP (“Sapia”) which is authorised and regulated by the Financial Conduct Authority (Firm Reference Number 550103). No undertaking, warranty or other assurance is given, and none should be implied, as to, and no reliance should be placed on, the accuracy, completeness or fairness of the information or opinions contained in this Document. The information contained in the Document is not subject to completion, alteration and verification nor should it be assumed that the information in the Document will be updated. The information contained in the Document has not been verified by Sapia, Outlier Ventures or any of its associates or affiliates. The Document should not be considered a recommendation by Sapia, Outlier Ventures or any of its directors, officers, employees, agents or advisers in connection with any purchase of or subscription for securities. Recipients should not construe the contents of this Document as legal, tax, regulatory, financial or accounting advice and are urged to consult with their own advisers in relation to such matters. The information contained in the Document has been prepared purely for informational purposes. In all cases persons should conduct their own investigation and analysis of the data in the Document. The information contained in the Document has not been approved by the Financial Conduct Authority. This Document does not constitute, or form part of, any offer of, or invitation to apply for, securities nor shall it, or the fact of its distribution, form the basis of or be relied upon in connection with any contract or commitment to acquire any securities. -
View the Slides
Pixel: Multi-Signatures for Consensus Manu Drijvers (DFINITY) Sergey Gorbunov (Algorand & University of Waterloo) Gregory Neven (DFINITY) Hoeteck Wee (Algorand & CNRS, ENS, PSL) 1 Permissioned/Proof-of-Stake Blockchains Consensus: nodes agree on sequence of blocks Proof of stake (PoS): nodes vote on block proposals, weighted by stake e.g., Algorand, Cardano, Ethereum Casper Permissioned: nodes vote by access structure e.g., Ripple, Hyperledger Fabric Permissioned/Proof-of-Stake Blockchains Consensus: nodes agree on sequence of blocks Proof of stake (PoS): nodes sign block proposals, weighted by stake e.g., Algorand, Cardano, Ethereum Casper Permissioned: nodes sign by access structure e.g., Ripple, Hyperledger Fabric Multi-Signatures in Blockchains single multi-signature Σ under pk1,...,pkn on m short signature, efficient verification (preferably ≈ single signature) [IN83, OO91, MOR01, BLS01, B03, BN06, BDN18, ...] The Problem of Posterior Corruption [BPS16] aka long-range attacks [B15], costless simulation [P15] Chain integrity assumption: ≤ fraction f of nodes/stake corrupt The Problem of Posterior Corruption [BPS16] aka long-range attacks [B15], costless simulation [P15] Chain integrity assumption: ≤ fraction f of nodes/stake corrupt The Problem of Posterior Corruption [BPS16] aka long-range attacks [B15], costless simulation [P15] Chain integrity assumption: ≤ fraction f of nodes/stake signing keys corrupt The Problem of Posterior Corruption [BPS16] aka long-range attacks [B15], costless simulation [P15] Chain integrity assumption: -
Analyzing the Darknetmarkets Subreddit for Evolutions of Tools and Trends Using LDA Topic Modeling
DIGITAL FORENSIC RESEARCH CONFERENCE Analyzing the DarkNetMarkets Subreddit for Evolutions of Tools and Trends Using LDA Topic Modeling By Kyle Porter From the proceedings of The Digital Forensic Research Conference DFRWS 2018 USA Providence, RI (July 15th - 18th) DFRWS is dedicated to the sharing of knowledge and ideas about digital forensics research. Ever since it organized the first open workshop devoted to digital forensics in 2001, DFRWS continues to bring academics and practitioners together in an informal environment. As a non-profit, volunteer organization, DFRWS sponsors technical working groups, annual conferences and forensic challenges to help drive the direction of research and development. https:/dfrws.org Digital Investigation 26 (2018) S87eS97 Contents lists available at ScienceDirect Digital Investigation journal homepage: www.elsevier.com/locate/diin DFRWS 2018 USA d Proceedings of the Eighteenth Annual DFRWS USA Analyzing the DarkNetMarkets subreddit for evolutions of tools and trends using LDA topic modeling Kyle Porter Department of Information Security and Communication Technology, NTNU, Gjøvik, Norway abstract Keywords: Darknet markets, which can be considered as online black markets, in general sell illegal items such as Topic modeling drugs, firearms, and malware. In July 2017, significant law enforcement operations compromised or Latent dirichlet allocation completely took down multiple international darknet markets. To quickly understand how this affected Web crawling the markets and the choice of tools utilized by users of darknet markets, we use unsupervised topic Datamining Semantic analysis modeling techniques on the DarkNetMarkets subreddit in order to determine prominent topics and Digital forensics terms, and how they have changed over a year's time. -
The Open Legal Challenges of Pursuing AML/CFT Accountability Within Privacy-Enhanced Iom Ecosystems∗
The open legal challenges of pursuing AML/CFT accountability within privacy-enhanced IoM ecosystems∗ Nadia Pocher PhD Candidate Universitat Aut`onomade Barcelona • K.U. Leuven • Universit`adi Bologna Law, Science and Technology: Rights of Internet of Everything Joint Doctorate LaST-JD-RIoE MSCA ITN EJD n. 814177 [email protected] Abstract This research paper focuses on the interconnections between traditional and cutting- edge technological features of virtual currencies and the EU legal framework to prevent the misuse of the financial system for money laundering and terrorist financing purposes. It highlights a set of Anti-Money Laundering and Counter-Terrorist Financing (AML/CFT) challenges brought about in the Internet of Money (IoM) landscape by the double-edged nature of Distributed Ledger Technologies (DLTs) as both transparency and privacy ori- ented. Special attention is paid to inferences from concepts such as pseudonymity and traceability; this contribution explores these notions by relating them to privacy enhanc- ing mechanisms and blockchain intelligence strategies, while heeding both core elements of the present AML/CFT obliged entities' framework and possible new conceptualizations. Finally, it identifies key controversies and open questions as to the actual feasibility of ef- fectively applying the \active cooperation" AML/CFT approach to the crypto ecosystems. 1 The Internet of Money and underlying technologies The onset and subsequent development of the so-called "crypto economy" significantly and ubiq- uitously transformed the global financial landscape. The latter has been extensively confronted with non-traditional forms of currencies since the Bitcoin launch in January 2009. Relevant industry-altering effects, both ongoing and prospective, have been outlined more clearly by ideas such as Initial Coin Offerings (ICOs) or the recently unveiled Facebook-led Libra initiative.