Transparent and Collaborative Proof-Of-Work Consensus
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American Bar Association Business Law Section Committee on Derivatives and Futures Law
American Bar Association Business Law Section Committee on Derivatives and Futures Law Winter Meeting 2018 Naples, Florida Friday, January 19, 2018 10:15 a.m. to 11:30 a.m. NEW PRODUCTS / FINANCIAL TECHNOLOGY Moderator for the Program: Conrad G. Bahlke, Willkie Farr &Gallagher LLP Speakers: Geoffrey F. Aronow, Sidley Austin LLP Debra W. Cook, Depository Trust & Clearing Corporation Katherine Cooper, Law Office of Katherine Cooper Isabelle Corbett, R3 David Lucking, Allen & Overy LLP Brian D. Quintenz, Commissioner, U.S. Commodity Futures Trading Commission ABA BUSINESS LAW SECTION DERIVATIVES & FUTURES LAW COMMITTEE 2018 WINTER MEETING NEW PRODUCTS / FIN TECH PANEL 2017 Developments in US Regulation of Virtual Currencies and Related Products: Yin and Yang January 5, 2018 By Katherine Cooper1 2017 was a year during which virtual currencies began to move into the mainstream financial markets. This generated significant legal and regulatory developments as U.S. regulators faced numerous novel products attempting to blend the old with the new. Although facing so many novel issues, the regulators’ responses tell a familiar story of the struggle to balance the yin of customer protection with the yang of encouraging financial innovation and competition. Below is a summary of 2017 developments from the SEC, CFTC, OCC, FinCEN and the States. I. Securities and Exchange Commission a. Bitcoin Exchange-Traded Products A number of sponsors of proposed Bitcoin exchange traded products had applications for approval pending before the Securities and Exchange Commission at the beginning of 2017. In March 2017, the SEC rejected a proposal backed by Tyler and Cameron Winklevoss.2 The Bats Exchange proposed a rule amendment which would list the shares of the Winklevoss Bitcoin Trust for trading. -
Rev. Rul. 2019-24 ISSUES (1) Does a Taxpayer Have Gross Income Under
26 CFR 1.61-1: Gross income. (Also §§ 61, 451, 1011.) Rev. Rul. 2019-24 ISSUES (1) Does a taxpayer have gross income under § 61 of the Internal Revenue Code (Code) as a result of a hard fork of a cryptocurrency the taxpayer owns if the taxpayer does not receive units of a new cryptocurrency? (2) Does a taxpayer have gross income under § 61 as a result of an airdrop of a new cryptocurrency following a hard fork if the taxpayer receives units of new cryptocurrency? BACKGROUND Virtual currency is a digital representation of value that functions as a medium of exchange, a unit of account, and a store of value other than a representation of the United States dollar or a foreign currency. Foreign currency is the coin and paper money of a country other than the United States that is designated as legal tender, circulates, and is customarily used and accepted as a medium of exchange in the country of issuance. See 31 C.F.R. § 1010.100(m). - 2 - Cryptocurrency is a type of virtual currency that utilizes cryptography to secure transactions that are digitally recorded on a distributed ledger, such as a blockchain. Units of cryptocurrency are generally referred to as coins or tokens. Distributed ledger technology uses independent digital systems to record, share, and synchronize transactions, the details of which are recorded in multiple places at the same time with no central data store or administration functionality. A hard fork is unique to distributed ledger technology and occurs when a cryptocurrency on a distributed ledger undergoes a protocol change resulting in a permanent diversion from the legacy or existing distributed ledger. -
Crypto-Asset Markets: Potential Channels for Future Financial Stability
Crypto-asset markets Potential channels for future financial stability implications 10 October 2018 The Financial Stability Board (FSB) is established to coordinate at the international level the work of national financial authorities and international standard-setting bodies in order to develop and promote the implementation of effective regulatory, supervisory and other financial sector policies. Its mandate is set out in the FSB Charter, which governs the policymaking and related activities of the FSB. These activities, including any decisions reached in their context, shall not be binding or give rise to any legal rights or obligations under the FSB’s Articles of Association. Contacting the Financial Stability Board Sign up for e-mail alerts: www.fsb.org/emailalert Follow the FSB on Twitter: @FinStbBoard E-mail the FSB at: [email protected] Copyright © 2018 Financial Stability Board. Please refer to: www.fsb.org/terms_conditions/ Contents Executive Summary ................................................................................................................... 1 1. Introduction ......................................................................................................................... 3 2. Primary risks in crypto-asset markets ................................................................................. 5 2.1 Market liquidity risks ............................................................................................... 5 2.2 Volatility risks ......................................................................................................... -
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. -
Piecework: Generalized Outsourcing Control for Proofs of Work
(Short Paper): PieceWork: Generalized Outsourcing Control for Proofs of Work Philip Daian1, Ittay Eyal1, Ari Juels2, and Emin G¨unSirer1 1 Department of Computer Science, Cornell University, [email protected],[email protected],[email protected] 2 Jacobs Technion-Cornell Institute, Cornell Tech [email protected] Abstract. Most prominent cryptocurrencies utilize proof of work (PoW) to secure their operation, yet PoW suffers from two key undesirable prop- erties. First, the work done is generally wasted, not useful for anything but the gleaned security of the cryptocurrency. Second, PoW is natu- rally outsourceable, leading to inegalitarian concentration of power in the hands of few so-called pools that command large portions of the system's computation power. We introduce a general approach to constructing PoW called PieceWork that tackles both issues. In essence, PieceWork allows for a configurable fraction of PoW computation to be outsourced to workers. Its controlled outsourcing allows for reusing the work towards additional goals such as spam prevention and DoS mitigation, thereby reducing PoW waste. Meanwhile, PieceWork can be tuned to prevent excessive outsourcing. Doing so causes pool operation to be significantly more costly than today. This disincentivizes aggregation of work in mining pools. 1 Introduction Distributed cryptocurrencies such as Bitcoin [18] rely on the equivalence \com- putation = money." To generate a batch of coins, clients in a distributed cryp- tocurrency system perform an operation called mining. Mining requires solving a computationally intensive problem involving repeated cryptographic hashing. Such problem and its solution is called a Proof of Work (PoW) [11]. As currently designed, nearly all PoWs suffer from one of two drawbacks (or both, as in Bitcoin). -
Blockchain Law: the Fork Not Taken
Blockchain Law The fork not taken Robert A. Schwinger, New York Law Journal — November 24, 2020 I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a wood, and I— I took the one less traveled by, And that has made all the difference. — Robert Frost Is the token holder — often the holder of some form of digital currency — always free to choose which branch of the fork to take? A blockchain is often envisioned as a record of a single continuous Background: ‘Two roads diverged in a sequential series of transactions, like the links of the metaphorical chain from which the term “blockchain” derives. But sometimes yellow wood’ the chain turns out to be not so single or continuous. Sometimes situations can arise where a portion of the chain can branch off A blockchain fork occurs when someone seeks to divide a into a new direction from the original chain, while the original chain blockchain into two branches by changing its source code, which also continues to move forward separately. This presents a choice is possible to do because the code is open. For those users who for the current holders of the digital tokens on that blockchain choose to upgrade their software, the software then “rejects about which direction they wish to follow going forward. In the all transactions from older software, effectively creating a new world of blockchain, this scenario is termed a “fork.” branch of the blockchain. However, those users who retain the old software continue to process transactions, meaning that But is the tokenholder—often the holder of some form of digital there is a parallel set of transactions taking place across two currency—always free to choose which branch of the fork to different chains.” See generally N. -
Bypassing Non-Outsourceable Proof-Of-Work Schemes Using Collateralized Smart Contracts
Bypassing Non-Outsourceable Proof-of-Work Schemes Using Collateralized Smart Contracts Alexander Chepurnoy1;2, Amitabh Saxena1 1 Ergo Platform [email protected], [email protected] 2 IOHK Research [email protected] Abstract. Centralized pools and renting of mining power are considered as sources of possible censorship threats and even 51% attacks for de- centralized cryptocurrencies. Non-outsourceable Proof-of-Work schemes have been proposed to tackle these issues. However, tenets in the folk- lore say that such schemes could potentially be bypassed by using es- crow mechanisms. In this work, we propose a concrete example of such a mechanism which is using collateralized smart contracts. Our approach allows miners to bypass non-outsourceable Proof-of-Work schemes if the underlying blockchain platform supports smart contracts in a sufficiently advanced language. In particular, the language should allow access to the PoW solution. At a high level, our approach requires the miner to lock collateral covering the reward amount and protected by a smart contract that acts as an escrow. The smart contract has logic that allows the pool to collect the collateral as soon as the miner collects any block reward. We propose two variants of the approach depending on when the collat- eral is bound to the block solution. Using this, we show how to bypass previously proposed non-outsourceable Proof-of-Work schemes (with the notable exception for strong non-outsourceable schemes) and show how to build mining pools for such schemes. 1 Introduction Security of Bitcoin and many other cryptocurrencies relies on so called Proof-of- Work (PoW) schemes (also known as scratch-off puzzles), which are mechanisms to reach fast consensus and guarantee immutability of the ledger. -
Short Selling Attack: a Self-Destructive but Profitable 51% Attack on Pos Blockchains
Short Selling Attack: A Self-Destructive But Profitable 51% Attack On PoS Blockchains Suhyeon Lee and Seungjoo Kim CIST (Center for Information Security Technologies), Korea University, Korea Abstract—There have been several 51% attacks on Proof-of- With a PoS, the attacker needs to obtain 51% of the Work (PoW) blockchains recently, including Verge and Game- cryptocurrency to carry out a 51% attack. But unlike PoW, Credits, but the most noteworthy has been the attack that saw attacker in a PoS system is highly discouraged from launching hackers make off with up to $18 million after a successful double spend was executed on the Bitcoin Gold network. For this reason, 51% attack because he would have to risk of depreciation the Proof-of-Stake (PoS) algorithm, which already has advantages of his entire stake amount to do so. In comparison, bad of energy efficiency and throughput, is attracting attention as an actor in a PoW system will not lose their expensive alternative to the PoW algorithm. With a PoS, the attacker needs mining equipment if he launch a 51% attack. Moreover, to obtain 51% of the cryptocurrency to carry out a 51% attack. even if a 51% attack succeeds, the value of PoS-based But unlike PoW, attacker in a PoS system is highly discouraged from launching 51% attack because he would have to risk losing cryptocurrency will fall, and the attacker with the most stake his entire stake amount to do so. Moreover, even if a 51% attack will eventually lose the most. For these reasons, those who succeeds, the value of PoS-based cryptocurrency will fall, and attempt to attack 51% of the PoS blockchain will not be the attacker with the most stake will eventually lose the most. -
Review Articles
review articles DOI:10.1145/3372115 system is designed to achieve common Software weaknesses in cryptocurrencies security goals: transaction integrity and availability in a highly distributed sys- create unique challenges in responsible tem whose participants are incentiv- revelations. ized to cooperate.38 Users interact with the cryptocurrency system via software BY RAINER BÖHME, LISA ECKEY, TYLER MOORE, “wallets” that manage the cryptograph- NEHA NARULA, TIM RUFFING, AND AVIV ZOHAR ic keys associated with the coins of the user. These wallets can reside on a local client machine or be managed by an online service provider. In these appli- cations, authenticating users and Responsible maintaining confidentiality of crypto- graphic key material are the central se- curity goals. Exchanges facilitate trade Vulnerability between cryptocurrencies and between cryptocurrencies and traditional forms of money. Wallets broadcast cryptocur- Disclosure in rency transactions to a network of nodes, which then relay transactions to miners, who in turn validate and group Cryptocurrencies them together into blocks that are ap- pended to the blockchain. Not all cryptocurrency applications revolve around payments. Some crypto- currencies, most notably Ethereum, support “smart contracts” in which general-purpose code can be executed with integrity assurances and recorded DESPITE THE FOCUS on operating in adversarial on the distributed ledger. An explosion of token systems has appeared, in environments, cryptocurrencies have suffered a litany which particular functionality is ex- of security and privacy problems. Sometimes, these pressed and run on top of a cryptocur- rency.12 Here, the promise is that busi- issues are resolved without much fanfare following ness logic can be specified in the smart a disclosure by the individual who found the hole. -
The Bitcoin Trading Ecosystem
ArcaneReport(PrintReady).qxp 21/07/2021 14:43 Page 1 THE INSTITUTIONAL CRYPTO CURRENCY EXCHANGE INSIDE FRONT COVER: BLANK ArcaneReport(PrintReady).qxp 21/07/2021 14:43 Page 3 The Bitcoin Trading Ecosystem Arcane Research LMAX Digital Arcane Research is a part of Arcane Crypto, bringing LMAX Digital is the leading institutional spot data-driven analysis and research to the cryptocurrency exchange, run by the LMAX Group, cryptocurrency space. After launch in August 2019, which also operates several leading FCA regulated Arcane Research has become a trusted brand, trading venues for FX, metals and indices. Based on helping clients strengthen their credibility and proven, proprietary technology from LMAX Group, visibility through research reports and analysis. In LMAX Digital allows global institutions to acquire, addition, we regularly publish reports, weekly market trade and hold the most liquid digital assets, Bitcoin, updates and articles to educate and share insights. Ethereum, Litecoin, Bitcoin Cash and XRP, safely and securely. Arcane Crypto develops and invests in projects, focusing on bitcoin and digital assets. Arcane Trading with all the largest institutions globally, operates a portfolio of businesses, spanning the LMAX Digital is a primary price discovery venue, value chain for digital nance. As a group, Arcane streaming real-time market data to the industry’s deliver services targeting payments, investment, and leading indices and analytics platforms, enhancing trading, in addition to a media and research leg. the quality of market information available to investors and enabling a credible overview of the Arcane has the ambition to become a leading player spot crypto currency market. in the digital assets space by growing the existing businesses, invest in cutting edge projects, and LMAX Digital is regulated by the Gibraltar Financial through acquisitions and consolidation. -
Coinbase Explores Crypto ETF (9/6) Coinbase Spoke to Asset Manager Blackrock About Creating a Crypto ETF, Business Insider Reports
Crypto Week in Review (9/1-9/7) Goldman Sachs CFO Denies Crypto Strategy Shift (9/6) GS CFO Marty Chavez addressed claims from an unsubstantiated report earlier this week that the firm may be delaying previous plans to open a crypto trading desk, calling the report “fake news”. Coinbase Explores Crypto ETF (9/6) Coinbase spoke to asset manager BlackRock about creating a crypto ETF, Business Insider reports. While the current status of the discussions is unclear, BlackRock is said to have “no interest in being a crypto fund issuer,” and SEC approval in the near term remains uncertain. Looking ahead, the Wednesday confirmation of Trump nominee Elad Roisman has the potential to tip the scales towards a more favorable cryptoasset approach. Twitter CEO Comments on Blockchain (9/5) Twitter CEO Jack Dorsey, speaking in a congressional hearing, indicated that blockchain technology could prove useful for “distributed trust and distributed enforcement.” The platform, given its struggles with how best to address fraud, harassment, and other misuse, could be a prime testing ground for decentralized identity solutions. Ripio Facilitates Peer-to-Peer Loans (9/5) Ripio began to facilitate blockchain powered peer-to-peer loans, available to wallet users in Argentina, Mexico, and Brazil. The loans, which utilize the Ripple Credit Network (RCN) token, are funded in RCN and dispensed to users in fiat through a network of local partners. Since all details of the loan and payments are recorded on the Ethereum blockchain, the solution could contribute to wider access to credit for the unbanked. IBM’s Payment Protocol Out of Beta (9/4) Blockchain World Wire, a global blockchain based payments network by IBM, is out of beta, CoinDesk reports. -
A Probe Survey of Bitcoin Transactions Through Analysis of Advertising in an On-Line Discussion Forum
Acta Informatica Pragensia, 2019, 8(2), 112–131 DOI: 10.18267/j.aip.127 Original Article A Probe Survey of Bitcoin Transactions Through Analysis of Advertising in an On-Line Discussion Forum Zoltan Ban 1, Jan Lansky 1, Stanislava Mildeova 1, Petr Tesar 1 Abstract Cryptocurrencies have become a major phenomenon in recent years. For IT, a breakthrough is both the cryptocurrency itself as a commodity and the technology that cryptocurrency development has brought. The article focuses on the bitcoin cryptocurrency as the most important cryptocurrency. A relatively unexplored topic is what goods or services are purchased for bitcoins. To track what bitcoins are spent on, it is necessary to look for places that are dedicated to trading cryptocurrencies. The bitcointalk.org forum was chosen as a source for our data mining. The aim of the article is to find an answer to the research question: What are bitcoins on the discussion forum bitcointalk.org planned to be spent on? As part of the research, an application was developed using a PHP script to gather information from the discussion forum (bitcointalk.org). There is some evidence which suggests what types of products or services people spend cryptocurrencies on. This research has proven that cryptocurrencies are used to buy and sell goods or services in the electronics and computer world segments. Today, these segments are widespread, which may speed up the integration of cryptocurrencies into everyday life. This applies, of course, only if the risks associated with cryptocurrencies do not increase. Keywords: Cryptocurrency, Bitcoin, On-Line Advertisement, Text Mining, Cybersecurity, Discussion Forum.