Blockchain Technologies and Cryptocurrencies

Prof. John E. Savage
Brown University

Brown University Courses

  1. CS 2952 A — Blockchains and Cryptocurrencies
  2. Lecture 13 of CSCI 1800, Cybersecurity and International Relations

Observations about the Internet and Cryptocurrencies

  1. Motto of the Internet Engineering Community: We reject: kings, presidents and voting. We believe in: rough consensus and running code. Appears in "A Cloudy Crystal Ball — Visions of the Future," by David Clark, 24th Internet Engineering Task Force, 1992
  2. A Declaration of the Independence of Cyberspace by John Perry Barlow, February 8, 1996
  3. A Declaration of the Dependence of Cyberspace by Moshe Y. Vardi, Communications of the ACM, Vol. 61 No. 3, Page 9, 2018
  4. CryptoCurrency Facts

Opinions about Blockchain Technologies

  1. Just Another Day for Bitcoin — a 25% Plunge: Digital currency down 48% from December high amid growing regulatory scrutiny by Mike Bird and Gregor STuart Hunter, The Wall Street Journal, January 16, 2018
  2. Blockchain's Broken Promises by Nouriel Roubini, Project Syndicate, January 26, 2018
  3. The Blockchain Pipe Dream by Nouriel Roubini and Preston Byrne, Project Syndicate, March 5, 2018
  4. Why Blockchain Will Survive, Even If Bitcoin Doesn't: Latest blockchain applications could bring overdue change to critical, if unsexy, functions in shipping, real estate and ... diamonds by Christopher Mims, The Wall Street Journal, March 11, 2018
  5. Blockchain is not only crappy technology but a bad vision for the future by Kai Stinchcombe, Medium, April 5, 2018
    "Projects based on the elimination of trust have failed to capture customers' interest because trust is actually so damn valuable."
  6. The Blockchain Movement is Underway. What Should CEOs Know?, FTI Journal, May 2018
  7. 187 THINGS THE BLOCKCHAIN IS SUPPOSED TO FIX, by Eric Griffin, Wired, May 25, 2018
  8. Alternatives to Blockchain by Jimmy Song, Medium, May 23, 2018
  9. Monetary Policy in the Digital Age: Crypto assets may one day reduce demand for central bank money by Dong He, International Monetary Fund, June 2018
    This article analyzes the consequences of replacing a fiat currency with a cryptocurrency.
  10. Top banker batters Bitcoin for sucky scalability, security: Australia's Reserve Bank sees no need for national cryptocurrencies, for now by Simon Sharwood, The Register, June 27 2018
    Tony Richard, head of payments policy at Australia's Reserve Bank, highlights the scaling problems associated with the Bitcoin currency.
  11. This Year's Blockchain Craze Mirrors the Early Days of the Internet by Iris Zhao, The Council on Foreign Relations, December 20, 2018
  12. Remember Bitcoin? Some Investors Might Want to Forget by Nellie Bowles, The New York Times, December 27, 2018
  13. Raising Money in the Crypto World Has Gotten a Lot Harder: The market for initial coin offerings, which boomed last year, has ground to a halt by Paul Vigna, The Wall Street Journal, March 31, 2019
  14. Amid Bitcoin Uncertainty, 'the Smart Money Knows That Crypto Is Not Ready' by Nathaniel Popper, The New York Times, April 2, 2019

Introduction to Bitcoins

  1. The Crypto-Currency: Bitcoin and its mysterious inventor by Joshua Davis, The New Yorker, October 10, 2011
    The author provides an introduction to bitcoin and describes his attempt to identify its author, Satoshi Nakamoto.
  2. How Bitcoin Works Under the Hood, CuriousInventor, YouTube, January 31, 2017 (A transcript of the video is available here.)
    This 22:24 minute video provides a technical introduction to bitcoin, the world's first cryptocurrency. It defines bitcoin transfers and explains how bitcoin ownership is certified, how transfers occur using a decentralized public blockchain, and the role of miners who collect transfers, solve a hard computational problem to obtain a proof of work, and form a block and append it to the blockchain. It also explains the verification process that each miner does to verify the ownership of bitcoin and the work of other miners, thereby realizing a system of trust without invoking a trusted centralized broker.
  3. The State of the Ethereum Network: After months of intense attention on blockchain technology and the Ethereum blockchain, we pull together statistics from across the network to provide a snapshot of Ethereum today, its past, and its roadmap ahead, Consensus, June 1, 2018

Blockchain Technologies

    Introduction to Blockchains

    1. What is blockchain? The most disruptive tech in years by Lucas Mearian, Computerworld, January 18,2018
      This article provides a high-level textual description of blockchains.
    2. What is Blockchain?, Centre for International Governance Innovation, YouTube, January 4, 2018
      This 6:26 minute video provides a quick overview of the operation of blockchains and their importance.
    3. Blockchains: How They Work and Why They'll Change the World by Morgen E. Peck, IEEE Spectrum, September 28, 2017
      This article provides more depth than the video and introduces the concept of smart contracts.
    4. Blockchain by Margaret Rouse, TechTarget,, July 26, 2017
    5. SPECIAL REPORT: BLOCKCHAIN WORLD, IEEE Spectrum, September 28, 2017
      This is a collection of 11 articles on blockchain technology.
    6. Decentralized Blockchain-Based Electronic Marketplaces by Hemang Subramanian, Communications of the ACM, January 2018 (A video providing an overview of blockchains is available here.)
    7. MIT's Blockchain Site
    8. Maurice Herlihy's Site for CSCI 2952-A
    9. Understanding The DAO Attack by David Siegel, Coindesk, June 25, 2016
    10. Realizing Policy Goals through Blockchain Technology, Centre for International Governance Innovation, July 6, 2017
    12. Wall Street Firms to Move Trillions to Blockchains in 2018 by Amy Nordrum, IEEE Spectrum, September 29,, 2017
    13. Do You Need a Blockchain? by Morgen E. Peck, IEEE Spectrum, September 29, 2017 Money pp 239-278, September 1, 2016
    14. 50+ Examples of How Blockchains are Taking Over the World by Matteo Gianpietro Zago, Medium, May 30, 2018

      DealBook, The New York Times, June 27,2018

    Scaling Issues

    1. Ensuring Network Scalibility: How to Fight Blockchain Bloat by Andrew Wagner, BitcoinMagazine, November 6, 2014
    2. What is the Lightning Network and how can it help Bitcoin scale? by Elizabeth Stark, coincenter, September 15, 2016
    3. Blockchains don't scale. Not today, at least. But there's hope. by Preethi Kasireddy, Hackernoon, August 23, 2017
    4. Bitcoin Hasn't Replaced Cash, but Investors Don't Care by Nathaniel Popper, December 6, 2017
      This article states that Bitcoin can handle about 5 transactions per second whereas Visa is able to handle about 25,000 transactions per second.
    5. Plasma: Scalable Autonomous Smart Contracts by Joseph Poon and Vitalik Buterin, Working Draft, August 11, 2017
    6. Bitcoin Lightning Network — 7 Things You Should Know by Lukas Schor, Medium, January 10, 2018
    7. The State of Scaling Ethereum: A concise overview of the challenges and solutions to scaling the Ethereum Network, Consensy, April 24, 2018
    8. Ethereum's Casper and Sharding New Design by Michael K. Spencer, Medium, June 16, 2018
    9. Blockchain phase 2: Will it scale? by Lucas Mearian, Computerworld, August 15, 2018
      As blockchain grows in popularity, so does the conundrum of how to scale it while maintaining or boosting performance so it can compete with today's transaction networks.

    Mutable Blockchains

    1. Accenture's Blockchain Redaction Solution by Martha Bennett, Accenture, April 2017
    2. Redactable Blockchain –or– Rewriting History in Bitcoin and Friends by Giuseppe Ateniese, Bernardo Magri, Daniele Venturi and Ewerton Andrade, The International Association for Cryptologic Research, May 11, 2017

    Consensus Algorithms

    1. Proof of Stake FAQ, by Moshe Simantov, GitHub, 2018
    2. Casper the Friendly Gadget by Buterin and Griffith
    3. Incentives in Casper the Friendly Gadget by Vitalik Buterin, Ethereum, August 27, 2017
    4. Decentralization in Bitcoin and Ethereum Networks by Gencer, Basu, Eyal, Renesse, and Sirer, Cornell University, January 11, 2018
    5. When IoT met blockchain by Frederic Paul, Networkworld, January 26, 2018
    6. A Concurrent Perspective on Smart Contracts by Ilya Sergey and Aquinas Hobor,, February 17, 2017
    7. IBM sees blockchain as ready for government use by Lucas Mearian, Computerworld, February 14, 2018
    8. The Eureka Moment That Made Bitcoin Possible: A key insight for the technology came to a physicist almost three decades ago at a Friendly's restaurant in New Jersey by Amy Whitaker, May 25, 2018
    9. Scaling Nakamoto Consensus to Thousands of Transactions per Second by Chenxing Li, Peilun Li, Dong Zhou, Wei Xu, Fan Long, and Andrew Chi-Chih Yao, arXiv:1805.03870, August 31, 2019
    10. Solida: A Blockchain Protocol Based on Reconfigurable Byzantine Consensus by Ittai Abraham, Dahlia Malkhi, Kartik Nayak, Ling Ren, and Alexander Spiegelman, arXiv 1612.02916, November 18, 2017
    11. Ethereum Plans to Cut Its Absurd Energy Consumption by 99 Percent by Peter Fairley, IEEE Spectrum, January 2, 2019

    Cryptocurrency Vulnerabilities

    1. BatchOverflow Exploit Creates Trillions of Ethereum Tokens, Major Exchanges Halt ERC20 Deposits by Sam Town, Cryptoslate, April 25, 2018
    2. Majority Is Not Enough: Bitcoin Mining Is Vulnerable by Ittay Eyal and Emin Gün Sirer, CACM, July 2018

    Problems with Smart Contracts

    1. The Curious Case of 184 Billion Bitcoin by Bruno, January 14, 2018
      The author explains how a failure to check for integer overflow in the Bitcoin software allowed two units of about 184 million bitcoin to be created and sent to accounts in 2010 until corrected.
    2. Blockchains from a Distributed Computing Perspective by Maurice Herlihy, Brown University, January 16, 2018
      "This article is a tutorial on the basic notions and mechanisms underlying blockchains, colored by the perspective that much of the blockchain world is a disguised, sometimes distorted, mirror-image of the distributed computing world." Maurice also explains how a failure to understand this lead to the theft of about $50 Million from the Decentralized Autonomous Organization (DAO) in 2016 by exploiting poorly designed "smart contracts."
    3. An Overview of Cryptocurrency Consensus Algorithms by Phil Glazer, HackerNoon, March 14, 2018
    4. This Yale Technology Could Fix Blockchain's Security Issues and Make It a Lot More Viable, Office of Cooperative Research, Yale University, 2018
      A team at Yale has developed technology to simplify verification of the correctness of smart contracts. When smart contracts are embedded in blockchains, they are permanent. If they contain errors, misuse of blockchain data can occur. The only way to fix this is to execute a hard fork, which requires rebuilding the blockchain from the point of the error.

    Databases for Blockchains

    1. Concerto: A High Concurrency Key-Value Store with Integrity by Arvind Arasu, Ken Eguro, Raghav Kaushik, Donald Kossmann, Pingfan Meng, Vineet Pandey, and Ravi Ramamurthy, Procs. 2017 ACM International Conference on Management of Data (SIGMOD), Pages 251-266

Available Blockchain Implementations

  1. Hyperledger Consortium, a product of the Linux Foundation. (See this article.)
  2. Microsoft wants to make blockchain networks enterprise-ready with its new Coco Framework by Frederic Lardinois, TechCrunch, August 10, 2017
  3. Announcing the Coco Framework for enterprise blockchain networks, Mark Russinovich, CTO, Microsoft Azure, August 10, 2017
  4. Corda, a distributed ledger technology.
    Corda is an open source blockchain project designed for business from the start. Only Corda allows you to build interoperable blockchain networks that transact in strict privacy. Corda's smart contract technology allows businesses to transact directly, with value.
  5. Quorum by J. P. Morgan
    Quorum™ is an enterprise-ready distributed ledger and smart contract platform.

The Bitcoin Mining Process

  1. Bitcoin Reward Halving Countdown
  2. In one chart, here's how much it costs to mine bitcoin in your state, by Ryan Vlastelica, MarketWatch, December 18, 2017
  3. A (Short) Guide to Blockchain Consensus Protocols by Amy Castor, coindesk, March 4, 2017
  4. What Is Cryptocurrency — How It Works, History & Bitcoin Alternatives by Brian Martucci, Money Crashers
  5. Crypto Mining — ETH — Not Worth Starting by Tyler, Medium, May 25, 2018


  1. Bitcoin: A Peer-to-Peer Electronic Cash System by Satoshi Nakamoto, published on the cryptography mailing list
  2. 100 Cryptocurrencies Described in Four Words or Less, by Nate Murray, TechCrunch, November 19, 2017
  3. Want to really understand how bitcoin works? Here's a gentle primer by Timothy B. Lee, Ars Technica, December 15, 2017
  4. Five myths about bitcoin by Joseph Bonneau and Steven Goldfeder, The Washington Post, December 15, 2017
  5. Bitcoin's Academic Pedigree by Arvind Narayanan, Jeremy Clark, Communications of the ACM, Vol. 60 No. 12, Pages 36-45, December 2017
  6. Algorand: Scaling Byzantine Agreements for Cryptocurrencies by Yossi Gilad, Rotem Hemo, Silvio Micali, Georgios Vlachos, and Nickolai Zeldovich, SOSP 2017
    Algorand provides a new way to create distributed ledgers that avoids important problems that arise with traditional blockchains.
    A 39:46 minute video of a talk given at Berkeley by Silvio Micali explains the basic concepts is available here. A longer and more complete 1:12:46 video produced by the ACM is available here.
  7. Merrill Lynch Bars Trading of Bitcoin Fund, Futures: Firm has already denied clients access to the bitcoin futures markets by Lisa Beilfuss, The Wall Street Journal, January 3, 2018
  8. Russia and Venezuela's Plan to Sidestep Sanctions: Virtual Currencies by Nathaniel Popper, Oleg Matsnev and Ana Vanessa Herrero, The New York Times, January 3, 2018
  9. Rise of Bitcoin Competitor Ripple Creates Wealth to Rival Zuckerberg by Nathaniel Popper, The New York Times, January 4, 2018
  10. SEC warns cryptocurrency investors of rampant illegal trading by Sylvan Lane, The Hill, January 4, 2018
  11. Ripple Steals Bitcoin's Thunder, Surges 1,135% in a Month by Paul Vigna, The Wall Street Journal, January 5, 2018
  12. Initial Coin Offerings and Cryptocurrencies Will be a Priority for FINRA in 2018 by Linn Foster Freedman, Robison + Cole, January 11, 2018
  13. MoneyGram Signs Deal to Work With Currency Startup Ripple: Money-transfer company will run a pilot program testing XRP, a digital currency by Paul Vigna and Peter Rudegeair, The Wall Street Journal, January 11, 2018
  14. Beyond the Bitcoin Bubble: Yes, it's driven by greed — but the mania for cryptocurrency could wind up building something much more important than wealth. by Steven Johnson, The New York Times, January 16, 2018
  15. New Cyberattack on Cryptocurrency Investors Came From North Korea, Report Says by Jonathan Cheng, The Wall Street Journal, January 17, 2018
  16. Credit Card Companies Don't Want You to Buy Bitcoin With Plastic by AnnaMaria Andriotis and Paul Vigna, The Wall Street Journal, January 25, 2018
  17. Cryptocurrency botnets are rendering some companies unable to operate by Dan Goodin, ArsTechnica, February 2, 2018
  18. Bitcoin's Plunge Weighs on Coin Offerings by Paul Vigna, The Wall Street Journal, February 7, 2018
  19. A $232 Million Cryptocurrency Fight Comes to a Close: Tezos team can move forward after nonprofit foundation chief who was locked in a battle for control of funds steps down by Paul Vigna, The Wall Street Journal, February 22, 2018
  20. What Bitcoin Rout? Sales of New Digital Tokens Are Still Soaring by Paul Vigna, The Wall Street Journal, February 22, 2018
  21. Bitcoin's Underlying Incentives by Yonatan Sompolinsky, Aviv Zohar Communications of the ACM, Vol. 61 No. 3, Pages 46-53, 2018
  22. Bitcoin Price, Business Insider
  23. Bitcoin Diamond/Super Bitcoin/BitCore: What You Need To Know by Jimmy Song, Medium, January 3, 2018
  24. Top Cryptocurrency Primer Guide in Bite Sized Notes by Michael Spencer, Medium, May 27, 2018
  25. Bitcoin Drop Sparks Broad Cryptocurrency Selloff by Paul Vigna, The Wall Street Journal, June 22, 2018
  26. Crypto Pioneer David Chaum Says He's Built a Better Bitcoin: A new platform, called Elixxir, promises to improve on bitcoin's speed by processing thousands of transactions a second by Paul Vigna, The Wall Street Journal, September 19, 2019

Cryptocurrency Exchanges

  1. Cryptocompare
    This site lists the current price in various currencies of 1994 cryptocurrencies.
  2. Bitcoin Plunges as South Korea Crafts Cryptocurrency Crackdown: South Korea is preparing a bill to ban the trading of cryptocurrencies on exchanges by Eun-Young Jeong and Gregor Stuart Hunter, The Wall Street Journal, January 11, 2018
  3. This week's Bitcoin crash was all about fraud and regulation by Simon Chandler, The Verge, January 18, 2018
  4. The Programmer at the Center of a $100 Billion Crypto Storm by Paul Vigna and Jim Oberman, The Wall Street Journal, January 23, 2018
  5. What's Bitcoin Worth? A New Plan to Bring Discipline to Crypto Prices by Alexander Osipovich, The Wall Street Journal, January 19, 2018
  6. Financial regulators subpoena major bitcoin exchange by Ali Breland, The Hill, January 30, 2018
  7. Cryptocurrency Firm Coinbase in Talks to Become SEC-Regulated Brokerage by Dave Michaels, The Wall Street Journal, April 6, 2018
  8. Other Countries Forge Ahead on Crypto Regulations by Laura Shin, The New York Times, June 27, 2018
  9. Bots Are Manipulating Price of Bitcoin in 'Wild West of Crypto': Abusive softrware runs largely unchecked on crypto exchanges, prompting regulatory concern by Paul Vigna and Alexander Osipovich, The Wall Street Journal, October 2, 2018

Initial Coin Offerings

  1. HoweyCoins PRE-ICO SALE IS LIVE!
  2. The SEC Has an Opportunity You Won't Want to Miss: Act Now!, U.S. Securities and Exchange Commission
    The SEC has created a website advertisiting a fake initial coin offering (ICO).
  3. Cryptocurrency ICO Stats 2018, CoinSchedule
  4. The Failure Rate of ICOs is Skyrocketing in 2018 by Michael K. Spencer, Medium, August 9, 2018

Cryptocurrency Scandals

  1. A Painful Lesson For The Ethereum Community by Frances Coppola, Forbes, July 21, 2016
  2. Bitcoin: $64m in cryptocurrency stolen in 'sophisticated' hack, exchange says by Samuel Gibbs, The Guardian, December 7, 2017
  3. Japanese Cryptocurrency Exchange Coincheck to Pay Back Customers by Peter Landers, The Wall Street Journal, January 27, 2018
  4. Bitcoin wallets vulnerable to security hacks, University of Ediburgh
  5. Cryptocurrency botnets are rendering some companies unable to operate by Dan Goodin, ArsTechnica, February 2, 2018
  6. BitGrail cryptocurrency exchange loses $170 million in Nano tokens
    "... the checks for whether you had a sufficient balance to withdraw were only implemented as client-side JavaScript"
  7. Cryptocurrency Worth $170 Million Missing From Italian Exchange: BitGrail says it lost about 17 million tokens of Nano by Paul Vigna, The Wall Street Journal, February 10, 2018
  8. Inside the World's Bigggest Cryptocurrency Hack — and How the Scammers Pulled it Off by Rob Wile, Money, January 29, 2018
  9. Feds charge former bitcoin exchange with fraud by Ali Breland, The Hill, February 21, 2018
  10. Crypto Wallet Vs. Address: Believe it or not, there's a difference! by Kenny Li, Hackernoon, May 22, 2018
  11. About $1.2 billion in cryptocurrency stolen since 2017 by Gertrude Chavez-Dreyfuss, Reuters, May 24, 2018
  12. Policing Cryptocurrencies Has Become a Game of Whack-a-Mole for Regulators by Peter J. Henning, The New York Times, May 31, 2018
  13. Making Bitcoin Legal by Ross Anderson, Ilia Shumailov and Mansoor Ahmed, Cambridge University Computer Laboratory, 2018
    The authors identify existing law that can be applied to making bitcoin legal.
  14. Bitcoin Falls Sharply After Another Cryptocurrency Exchange Is Hacked: The largest cryptocurrency has lost more than half its value this year by Steven Russolillo, The Wall Street Journal, June 10, 2018
  15. Bitcoin's Price Was Artificially Inflated, Fueling Skyrocketing Value, Researchers Say by Nathaniel Popper, The New York Times, March 30, 2018
    "A concentrated campaign of price manipulation may have accounted for at least half of the increase in the price of Bitcoin and other big cryptocurrencies last year."
  16. Major cryptocurrency exchange Bithumb halts trading after more than $31 million hack by Brian Murphy, The Washington Post, June 19, 2018
  17. Inside the Crypto World's Biggest Scandal by Gideon Lewis-Kraus, Wired, June 19, 2018
  18. A Fifth of All Bitcoin Is Missing. These Crypto Hunters Can Help by Elliott Krause, The Wall Street Journal, July 5, 2018
  19. Cryptocurrency's Criminal Revolution by Tyler Eliot Bettilyon, Medium, July 12, 2018
  20. Cryptocurrency Exchanges Are Getting Hacked Because It's Easy: Regulatory gaps and insufficient levels of defense have made some exchanges simple to breach by Steven Russolillo and Eun-Young Jeong, The Wall Street Journal, July 16, 2018
  21. Traders Are Talking Up Cryptocurrencies, Then Dumping Them, Costing Other Millions: 'Pump groups' fuel millions in trading activity, with price rises followed by quick falls by Shane Shifflett and Paul Vigna, The Wall Street Journal, August 5, 2018
  22. The Big Blockchain Lie by Nouriel Roubini, Project Syndicate, Octobr 15, 2018
  23. ICO Firms Paid Themselves $24 Billion Absent of Accountability or Much Effort by Shaurya Malwa, CRYPTOSLATE, January 18, 2019
  24. A 'Blockchain Bandit' is Guessing Private Keys and Scoring Millions by Andy Greenberg, WIRED, April 23, 2019
  25. A new cryptocurrency mining malware uses leaked NSA exploits to spread across enterprise networks by Zack Whittaker, TechCrunch, April 25, 2019

Blockchain and Cryptocurrency Governance

  1. BitLicense Regulatory Framework, New York State
  2. Russia and Venezuela's Plan to Sidestep Sanctions: Virtual Currencies by Nathaniel Popper, Oleg Matsnev and Ana Vanessa Herrero, The New York Times, January 3, 2018
  3. U.S. Sanctions Weapon Is Under Threat, but Not From Bitcoin by Keith Johnson and Elias Groll, Foreign Policy, January 24, 2018
  4. Bitcoin's real story isn't the rampant speculation, but its untold potential by Steve Forbes, The Hill, January 18, 2018
  5. Cryptocurrencies Are Top of Mind for G20 Finance Ministers: Anonymity and borderless transactions create a perfect climate for money laundering by Samantha St. Amand, Centre for International Governance Innovation, February 20, 2018
  6. Women in Cryptocurrencies Push Back Against 'Blockchain Bros' by Nellie Bowles, The New York Times, February 25, 2018
  7. G20 leaders to hold fire on cryptocurrencies amid discord: sources by Francesco Canepa, Reuters, March 19, 2018
  8. Bitcoin Could Become Illegal Almost Everywhere, After Shocking Discovery in The Blockchain: There's something hidden inside it. by Peter Dockrill, Science Alert, March 22, 2018
  9. Venture Capitalists Seek 'Safe Harbor' for Virtual Currencies by Nathaniel Popper, The New York Times, April 19, 2018
  10. A Former Top Wall Street Regulator Turns to the Blockchain by Nathaniel Popper, The New York Times, April 22, 2018
  11. The Crypto Crime Wave Is Here: From stickups and drug deals to white-collar scams, cryptocurrency-related crime is soaring and law enforcement is scrambling to keep up by Corinne Ramey, The Wall Street Journal, April 26, 2018
  12. Blockchain Will Be Theirs, Russian Spy Boasted at Conference by Nathaniel Popper, April 29, 2018
  13. Cryptocurrency Regulation Update (May 2018) by Phil Glazer, Hackernoon, May 1, 2018
  14. Recent Trends in Virtual Currency Regulation, Enforcement, and Litigation by Sharon Brown-Hruska and Trevor Wagener, NERA, May 21, 2018
  15. Regulatory uncertainty could stymy blockchain adoption: Even as companies seek to integrate the distributed ledger technology into their business models, uncertainty about the regulatory landscape is seen as a major stumbling block. By Lucas Mearian, Computerworld, June 7, 2018
  16. Decentralized Blockchain Governance by Daniel Larimer, Medium, June 20, 2018
  17. State of Cryptocurrencies: Summer 2018 by Adam Taché, Hackernoon, June 23, 2018
  18. Cryptocurrency Regulation Update (June 2018) by Phil Glazer, Hackernoon, June 12, 2018
  19. COINBASE DOUBLES DOWN ON THE FUTURE OF DIGITAL IDENTITY by Gregory Barber, Wired, August 15, 2018

Energy Consumption

  1. The Hard Math Behind Bitcoin's Global Warming Problem by Adams Rogers, Wired, December 15, 2017
  2. There Is Nothing Virtual About Bitcoin's Energy Appetite by Nathaniel Popper, The New York Times, January 21, 2018
  3. Bitcoin's alarming carbon footprint, Spyros Fonteinis, Nature, Vol. 554, February 8, 2018
  4. Cryptocurrency mining in Iceland is using so much energy, the electricity may run out by Rick Noack, The Washington Post, February 13, 2018
  5. Bitcoin Mania Triggers Miner Influx to Rural Washington by Alison Sider, The Wall Street Journal, February 11, 2018
  6. Salon to use readers' computers to mine cryptocurrency by Julia Manchester, The Hill, February 13, 2018
  7. Salon Is Asking Readers to Mine Cryptocurrency if They Don't Want to See Ads by AAron Mark, Slate, February 13, 2018
  8. Is Bitcoin a Waste of Electricity, or Something Worse? by Binyamin Appelbaum, The New York Times, February 28,2018
  9. Cryptocurrency mining is neither wasteful nor uneconomic by Stuart Wimbush, Nature, March 21, 2018
  10. Why it's time to stop mining cryptocurrency and look to the future of blockchain: The time has come to stop mining cryptocurrencies., by Alex Stand, Medium, April 3, 2018
  11. Iceland Takes Hard Look at Tech Boom Sparked by Its Cheap, Bountiful Power by Zeke Turner, The Wall Street Journal, April 19, 2018
    By 2030, data centers and all internet-related activity, from streaming video to analyzing financial data to storing software, photos and emails, could use more electricity than all of China did in 2018.
  12. Deconstructing the Blockchain to Approach Physical Limits by Vivek Bagaria, Sreeram Kannan, David Tse, Giulia Fanti, and Pramod Viswanath, axXiv:1810.08092, October 18, 2018
  13. Ethereum Plans to Cut Its Absurd Energy Consumption by 99 Percent by Peter Fairley, IEEE Spectrum, January 2, 2019

Commercial Offerings

  1. IBM and Stellar Are Launching Blockchain Banking Across Multiple Countries by Jeff John Roberts, Fortune, October 16, 2017
    An overview of Stellar is given here. A comparison of Stellar with other blockchains is available here. And a detailed explanation of Stellar is given here.
  2. Need help on blockchain? These are the top three experts: How IBM, Microsoft and Accenture have made themselves consultants of choice by Finbarr Toesland, The Times of London,, November 16 2017
  3. Google Is Working on Its Own Blockchain-Related Technology by Olga Kharif and Mark Bergen, Bloomberg Technology, March 2,1 2018
  4. Twitter is joining Facebook and Google in banning cryptocurrency advertisements: The ban isn't yet official, but should be soon. by Kurt Wagner, recode, March 19, 2018
  5. Google to Ban Ads for Cryptocurrencies: New policy follows Facebook's lead, takes effect in June by Lara O'Reilly and Douglas MacMillan, The Wall Street Journal, March 13, 2018
  6. Goldman Sachs to Open a Bitcoin Trading Operation by Nathaniel Popper, The New York Times, May 2, 2018
  7. IBM partners Stronghold for new digital stable coin by Gertrude Chavez-Dreyfuss, Reuters, July 17, 2018
  8. Blockchain Efforts Move Beyond the Hype: 'This is Happening Now' by Matthew Leising, Bloomberg, July 19, 2018
  9. Cryptocurrency Startups Combine as Wall Street Blockchain Effort Falters by Paul Vigna, The Wall Street Journal, September 10, 2018

Advice on Blockchains

  1. Blockchain How this technology could impact the CFO
  2. Blockchain reaction: Tech plans for critical mass
  3. Blockchain: the hype, the opportunity and what you should do by Angus Champion de Crespigny, Ernst & Young LLP, 2016
  4. NISTIR 8202 (Draft) Blockchain Technology Overview by Dylan Yaga (NIST), Peter Mell (NIST), Nik Roby (G2), Karen Scarfone (Scarfone Cybersecurity), NIST

Interledger Currency Exchanges

  1. Interledger: How to Interconnect All Blockchains and Value Networks by Evan Schwartz and Vanessa Pestritto, Medium, October 3, 2018

Curated List of Publications by Philippe Camacho

  1. Papers on Bitcoins, Blockchains, and Smart Contracts


  1. What is the Privacy Coin Matrix? by Michael Spencer, Medium, May 21, 2018

News Reports

  1. Ethereum is Not Secure and it's Delayed its Upgrade again by Michael K. Spencer, Medium, January 16, 2019

John Savage