Showing posts with label cryptocurrency. Show all posts
Showing posts with label cryptocurrency. Show all posts

Saturday, April 21, 2018

Nicholas Weaver on blockchain and cryptocurrencies

This slide show and lecture by Nicholas Weaver, who the professor doing the introduction said has a particularly interesting Twitter feed, @ncweaver Blockchains and Cryptocurrencies: Burn It With Fire 04/20/2018



I already knew that Bitcoin and similar digital cryptocurrencies were basically a version of 19th-century bank-issued currency, only 19th-century bank-issued currency, only without as much security. And that they featured the same basic problem as the gold standard. And that they can be hacked, although technically I think it's the "blockchain" platform on which it runs rather than the Bitcoin itself that gets hacked. And that they are heavily used for criminal activity and require enormous amounts of power to "mine". Weaver reinforced all that and added to it.

A slide that comes up at 18:00 in the video says that Bitcoin alone, not counting other cryptocurrencies, uses as much power as all of New York City. He also says that only three Bitcoin transactions can be processed per second *worldwide*, which is incredibly slow and inefficient compared to systems currently being used by banks.

Previously I had thought that the blockchain technology might be useful for some kinds of record storage. But Weaver argues that even this is unlikely. (Actually, he pretty much dismisses it entirely.) He makes the cases that other digitial platforms already being used are more secure, effective, and efficient than blockchain for document storage and verification purposes.

Tuesday, January 16, 2018

Decrypting the concepts of blockchains and cryptocurrencies

I'm fascinated by cryptocurrencies. But I've yet to be convinced that they offer major advantage to regular currencies.

Sue Halpern's essay Bitcoin Mania New York Review of Books 12/21/2017 is informative. But it also serves to reinforce my suspicion that cryptocurrencies at the moment are some combination of a high-risk speculative bubble, a techie fad, a swindle and a libertarian daydream that takes way too much energy and is based of thin-ice economic assumptions.

Halperin flags the problem with the renowned unhackability (to date) of Bitcoin, the best known of the crytocurrencies at the moment. Digital currencies like Bitcoin and Ether - there's not even a consensus yet on whether the names should be capitalized or not - run on a distributed-ledger network arrangement called a blockchain. Large blockchains are not easy to hack. Yet.

But to buy and use the digital currencies, people need other applications like exhanges and wallets. Thus the problem as Halperin describes:
While a blockchain is not a full-on solution to fraud or hacking, its decentralized infrastructure ensures that there are no “honeypots” of data available for criminals to exploit. Still, touting a bitcoin-derived technology as the answer to cybercrime may seem a stretch in light of the high-profile — and lucrative — thefts of cryptocurrency over the past few years. [David] Gerard notes that “as of March 2015, a full third of all Bitcoin exchanges” — where people stored their bitcoin — “up to then had been hacked, and nearly half had closed.” There was, most famously, the 2014 pilferage of Mt. Gox, a Japanese-based digital coin exchange, in which 850,000 bitcoins worth $460,000,000 disappeared. Two years later another exchange, Bitfinex, was hacked and around $60 million in bitcoin was taken; the company’s solution was to spread the loss to all its customers, including those whose accounts had not been drained. Then there was the theft via malware of $40 million by a man in Pennsylvania earlier this year. He confessed, but the other thieves slipped away, leaving victims with no way to retrieve their funds.

Unlike money kept in a bank, cryptocurrencies are uninsured and unregulated. That is one of the consequences of a monetary system that exists — intentionally — beyond government control or oversight. It may be small consolation to those who were affected by these thefts that neither the bitcoin network nor the Ethereum network itself has been breached, which perhaps proves the immunity of the blockchain to hacking. (In 2016, there was a $60 million hack of a company running on the Ethereum system, but the theft occurred because there was a bug in that company’s software.) [my emphasis]
For normal household or business purposes, this is like using a bank with no deposit insurance, or trusting your 401(k) savings build up over 30 years to a penny-stock operator.

She also gives some illustration of the energy issue with cryptocurrencies. With Bitcoin, new instances of the cryptocurrency are created by "miners." The blockchain process makes this a validation process that requires a staggering amount of electricity:
When the bitcoin network began operating in 2009, people could run the validation program on their personal computers and earn bitcoins if their computer solved the puzzle first. As demand for bitcoin increased, and more people were vying to find the random, algorithmic proof of work validation number, speed became essential. Mining began to require sophisticated graphics cards and, when those proved too slow, special, superfast computers built specifically to validate transactions and mine bitcoins. Individual miners have dropped out for the most part, and industrial operators have moved in. These days, mining is so computer-intensive that it takes place in huge processing centers in countries with low energy costs, like China and Iceland. One of these, in the town of Ordos, in Inner Mongolia, has a staff of fifty who oversee 25,000 computers in eight buildings that run day and night. A company called BitFury, which operates mining facilities in Iceland and the Republic of Georgia and also manufactures and sells specialized, industrial processing rigs, is estimated to have mined at least half a million bitcoins so far. At today’s price, that’s worth around $7.5 billion.

Still, it’s not exactly free money. Marco Streng, the cofounder of Genesis Mining, estimates that it costs his company around $400 in electricity alone to mine each bitcoin. That’s because bitcoin mining is not only computationally intensive, it is energy-intensive. By one estimate, the power consumption of bitcoin mining now exceeds that of Ireland and is growing so exponentially that it will surpass that of the entire United States by July 2019. A year ago, the CEO of BitFury, Valery Vavilov, reckoned that energy accounted for between 90 and 95 percent of his company’s bitcoin-mining costs. According to David Gerard—whose new book, Attack of the Fifty Foot Blockchain, is a sober riposte to all the upbeat forecasts about cryptocurrency like the Tapscotts’—“By the end of 2016,” a single mining facility in China was using “over half the estimated power used by all of Google’s data centres worldwide at the time.” [my emphasis in bold]
One of the advantages of cryptocurrencies was supposed to be that they could avoid or minimized transactions fees. But the transaction fees involved in using them can be significant. With Bitcoins, the validation process for mining and using them also makes them significantly slower in terms of the number of transactions that can be processed in a given length of time than what "legacy" financial companies can do. Halperin writes, "transactions can be held up for hours or days or dropped altogether."

So, we've got a type of currency that's slow, expensive to use, very volatile in value, insecure, un-insurable, and not backed by a government. Remind me again just why I would want to use this.

Even for shady businesses like drugs, illegal arms deals, or money-laundering, these strike me as big drawbacks. Oh yeah, those have the added legal risks as well.

One of the nice things about articles like Halperin's at this moment in time is that they include helpful definitions of what techie things like a blockchain are:
A blockchain is, essentially, a way of moving information between parties over the Internet and storing that information and its transaction history on a disparate network of computers. Bitcoin, for example, operates on a blockchain: as transactions are aggregated into blocks, each block is assigned a unique cryptographic signature called a “hash.” Once the validating cryptographic puzzle for the latest block has been solved by a mining computer, three things happen: the result is timestamped, the new block is linked irrevocably to the blocks before and after it by its unique hash, and the block and its hash are posted to all the other computers that were attempting to solve the puzzle. This decentralized network of computers is the repository of the immutable ledger of bitcoin transactions.
Blockchains are apparently far more useful for the secure storage of data. Halperin suggests that the use of blockchains for "smart contracts" is a potential valuable usage.

But the power demands alone would seem to be a major issue for any system that requires the kind of continuous fast transactions that a cryptocurrency does.

She also discusses ICO, i.e., "initial coin offerings."

Sunday, January 14, 2018

Venezuela's Petro: Really cryptocurrency? Or too real to be crypto? Or not currency enough to be currency?

"Cryptocurrency" is an interesting neologism. (At least it's relatively "neo" for me.) It's used to refer to digital currencies like Bitcoin and Ether. One implication of the "crypto" in the name is related to "encryption," which implies a high level of security.

But another meaning of "crypto-" as the first part of a word is also "semi-" or "phony." Cryptozoology is the study of animals that don't exist, e.g., a contemporary Tyrannosaurus Rex in some obscure jungle, or Chupacabra, or the Loch Ness Monster.

Mirriam-Webster Online defines the adjective "crypto" this way: "not openly avowed or declared —often used in combination [e.g.,] crypto-fascist"

Frances Coppola invokes both meanings of "cryptocurrency" in Venezuela's 'Cryptocurrency' Isn't Really A Cryptocurrency At All Forbes 01/08/2018.

So, does she mean that it's a real currency? Or that it's a crypto-cryptocurrency?

She explains her usage by noting, "The whole point of cryptocurrencies like Bitcoin is that they aren’t 'issued' by any government, central bank or other 'authority.' No-one controls them. They are decentralized, anonymous and subversive."

In that perspective, cryptocurrency is not only encrypted in the software. It's also not a "real" currency like one backed by the government.

The Venezualan digital instrument is called a "Petro." As she explains, the Venezuelan government of Nicolás Maduro "is planning to issue a Venezuelan government cryptocurrency, backed by the country’s reserves of oil, gas, gold and diamonds. One unit of the new cryptocurrency – the 'petro' – will be backed by one barrel from Venezuela’s Orinoco oilfield, currently valued at $59." (Criptomoneda is the Spanish for cryptocurrency. Moneda virtual for digital currency.)

She argues that because it's in fact issued by the government and regulated by the government in a centralized way, it shouldn't be regarded as a cryptocurrency. It's more like a second currency, or an auxiliary currency, or, as she plausibly argues, a "digital oil-backed security":
Online cryptocurrency magazines report that over 860,000 Venezuelans have registered with Venezuela’s new Registry of Cryptocurrency Miners, which is the only portal through which the petro can be mined. Yes, you read that right - in Venezuela, government licenses its cryptocurrency miners, just as it licenses its banks. Furthermore, the operation of the new currency will be supervised by the Superintendency of Cryptocurrencies and Related Assets. Government controls mining, government supervises operations, government sets the price … the petro is looking less and less like a real cryptocurrency, isn’t it?
It can't a "real cryptocurrency" if it's not actually a currency. Or not actually "crypto" in the sense of being issued independently of governments, who are the ones who issue real currency. Could we say that a cryptocurrrency isn't one if it's not really "crypto"?
In fact, why are we calling this a cryptocurrency at all? Really, it’s a digital oil-backed security. Recording transactions on a blockchain and adding some cryptography doesn’t make it a cryptocurrency. It isn’t decentralized, it isn’t anonymous, and it isn’t going to be used to buy and sell goods and services in Venezuela, although there are suggestions that it could be used to pay international suppliers. And above all, its value depends on the trustworthiness of a government already in default on its international obligations. [my emphasis]
An economics question for the 2010s.

See also:

Thursday, January 11, 2018

The brave new world (?) of cryptocurrencies

One of my New Year's Resolutions is to learn more about crytocurrencies like Bitcoin and blog about them occasionally.

Let's start off with Paul Krugman, Nobel Prize-winning Economist Paul Krugman on Tax Reform, Trump, and Bitcoin Business Insider 12/15/2017. The section about bitcoin comes in the latter part of the video. But Jacqui Frank et al have provided us the transcript of that section, PAUL KRUGMAN: Bitcoin is a more obvious bubble than housing was Business Insider 12/15/2017:
Josh Barro: Finally, I want to ask you about Bitcoin. Does the runup in bitcoin prices make any sense to you?

Paul Krugman: No.

Barro: What's going on here?

Krugman: Bitcoin, nobody understands it. Which is for the time being a positive. It comes with this -

Barro: A positive for the prices?

Krugman: For the price of it. It's got this mystique about it, because it's some fancy technological thing that nobody really understands. There's been no demonstration yet that it actually is helpful in conducting economic transactions. There's no anchor for its value. You know, unlike pieces of paper with dead presidents on them, those are anchored by the fact that you can use them to pay taxes. There's not anchor for bitcoin. But bitcoin has developed this mystique. The price is going up, partly, it's tied up with Libertarian stuff ... I'm told that there are apocalyptic, the-end-is-coming guys who are accumulating bitcoin because once we turn into a Mad Max wasteland, having a digitally distributed – nevermind. So ... I think it really doesn't make a whole lot of sense. And the psychology of it is clearly — if you're using the shoeshine boy test, my barber asked me about bitcoin. The feeling that people are caught up in something that they really don't understand, is overwhelming. [my emphasis in italics]
Krugman succinctly introduces several important aspects about Bitcoin right there. Investing in it is a pure gamble. It's not an actual currency in that it's not backed by anything, except in this case by pure faith in speculation itself. It's a techie thing. And nobody really understands it in a comprehensive way because it's new and complicated. And it has advocates who indulge in the most discredited kinds of "libertarian" economic ideology. Oh, and investing your money in it at this point is basically a pure gambling operation.

Scientific American for January includes three articles on cryptocurrency under the rubric, "The Future of Money":
  • Alexander Lipton and Alex "Sandy" Pentland, "Breaking the Bank"
  • John Pavlus, "The World Bicoin Created"
  • Natalie Smolenski, "The Evolution of Trust"

Blätter 2017:12 carried two articles giving some basics of Bitcoin, under the general title "Bitcoin: Der gefährliche Hype" ("Bicoin: The dangerous hype"):

Justin Kirkland has a helpful guide,Okay, Here's What You Actually Need to Know About Bitcoin Esquire 12/27/2017.

And Roula Khalaf uses the Bitcoin craze to do a little millennial-bashing, an unwholesome current habit of people who are annoyed at growing older, in A bitcoin bubble made in millennial heaven Financial Times 01/10/2018.

What is Bitcoin? A cryptocurrency. Like any currency, it acts as a medium of exchange and a store of value.

What is a cryptocurrency? Here a brief descdription from a sidebar to Pavlus's article: "A form of digital currency that relies on the mathematics of cryptography to control how and when units of the currency are created and to ensure secure transfer of funds." It uses encryption and is based on the blockchain technology.

What is a blockchain? It's a software platform that uses various separate computers to create a "distributed ledger." It provides a way of validating information in a way that is not dependent on a central institution such as a single corporation or a central bank. Blockchain technology is not used only for cryptocurrencies. Pavlus discusses its current use by governments, universities, financial institutions and individuals, and its potential for far more widespead use for self-driving vehicles, medical data handling, and creating a multiple-node "global supercomputer" function. Blockchain systems are used for many other things than cryptocurrenies, though the latter may be the best known at this point, though not necessarily the most important.

But Bitcoin and other current cryptocurrencies are based on blockchain technology. As Pavlus puts it, "What people call 'blockchain' is a technology that makes Bitcoin possible — an infrastructure that can be used for tracking many types of transactions. Blockchain technology exists without Bitcoin — but not the reverse. Think of Bitcoin as a kind of application that runs 'on' the blockchain, much like Web sites run on the Internet."

William Mougayar in The Business Blockchain: Promise, Practice and Application of the next Internet Technology (2016) defines a cryptocurrrency based on the blockchain is characterized in particular by four aspects:
  • Peer-to-peer electronic transactions and interactions
  • Without financial institutions
  • Cryptographic proof instead of central trust
  • Put trust in the network instead of in a central institution
Kirkland notes that Bitcoin "was invented to be unhackable, untraceable, and safe for investors."

Unlike normal currencies, Bitcoin is not backed by a store of material stuff like gold nor by the full faith and credit of a government, like national currencies and the euro. That's what Krugman means when he says that Bitcoin has "no anchor for its value." It's based essentially on faith. It has values in facilitating trade or transmission of values from one person to another because other people accept it and all participants have some level of faith that other users will continue to accept it as having value. We might call it a faith-based currency.

Rudolf Hickel describes it this way, "The one and only thing that counts is the trust in each digital curreny." ("Einzig und allein das Vertrauen in die jeweilige Digitalwährung zählt.")

Khalaf writes, "One person ventured that blockchain was the casino and bitcoin the chips — an apt description since investing in cryptocurrencies is very much like gambling."

A cryptocurrency could be tied to a hard asset or basket of assets. Lipton and Pentland distinguish between a Bitcoin-type peer-to-peer network and what they call "peer-to-peer Tradecoin network." They write, "As with Bitcoin, transactions would be made directly between users and are publicly recorded in a blockchain. But consensus is maintained by designated validators. Tradecoin’s value is backed by real assets supplied by sponsors, so its price is relatively stable." Tradecoin is the name they use for a project of theirs at MIT. They describe its basic concept this way: "it will be indelibly logged on a blockchain and anchored at all times to a basket of real-world assets such as crops, energy or minerals."

But here is where economics raises questions. Once a cryptocurrency is anchored in this way, it would then present the risk that if it were used on a wide enough scale to have macroeconomic effects, it could wind up having the same kind of negative effects that the gold standard had in Europe during the Great Depression, or that the euro had in the "periphery" countries of the eurozone in the Great Recession, or that the dollar peg had in Argentina in the 2001 financial crisis there.

So it's not at all clear to me what the advantage of cryptocurrency on a large scale would be compared to national currencies backed by the legal "full faith and credit" of their governments or to the current digital banking and payment systems.

Security is one big feature that cryptocurrency advocates tout. Pavlus notes, "Some experts say that a cryptocurrency like Bitcoin has value because of its security (the Bitcoin blockchain has never been hacked—yet)."

Still, that security is based on faith in the blockchain network. The idea is that because there are so many nodes in the peer-to-peer network that hacks on one or several of them would not be able to override the verification mechanism. If that doesn't sound entirely reassuring after over a year of hype about Russian hackers, there really is good reason for reservations. For one thing, other cyptocurrencies have been hacked, as Pavlus explains, "... even coins with impressive technical bona fides can be risky. The DAO—a “decentralized autonomous organization” running on Ethereum that raised over $100 million in 2016 — "had a bug" (in [MIT's Christian] Catalini’s understated terms) that allowed hackers to make off with $50 million worth of Ether," another cryptocurrency.

A $50 million hack sounds like quite a security gap! Especially since it apparently represented 50% of the total value of the Ether cryptocurrency. Pavlus quotes Gün Sirer of Cornell advising that peer-to-peer validation structure runs on the “assumption that a majority of nodes in their network are benign,” i.e., operating with integrity according to the rule of the blockchain. Bitcoin does not rely on encryption for security, it relies as the distributed ledger that the nodes constitute.

And it's worth paying close attention to what is being discussed when we heard that "Bitcoin" hasn't been hacked. It's one thing to say that the Bitcoin blockchain itself has not been hacked. But to buy Bitcoins in the first places, users have to rely on accessory software applications. Natalie Smolenski advises:
The application layer is where untold confusion and often outright bad faith can reign. The history of Bitcoin, for example, is littered with cryptocurrency exchanges and wallet providers who left gaping security flaws in their applications, leading to high-profile hacks and accusations of embezzlement. In the case of the Ethereum network, vulnerabilities have resulted in the theft or loss of millions of dollars in its Ether cryptocurrency, with virtually no recourse for users. In general, using any application built by a trusted third party to hold your blockchain-based digital assets is still a highly insecure proposition.

This is the crux of blockchain’s catch-22: the public won’t use blockchains without user-friendly applications. But user-friendly applications often achieve that ease through centralization, which replicates the conditions of control that blockchains sought to circumvent. [my emphasis]
And that centralization provides a more convenient point of attack for hackers than the widely distributed peer-to-peer network of the blockchain itself.

And Hickel writes, "In August 2016 alone, hackers stole Bitcoins with a market value of 58 million euros." ("Allein im August 2016 haben Hacker Bitcoins mit einem Marktwert von 58 Mio. Euro gestohlen.") Presumably these were stolen from the ancillary applications that aren't part of the the Bitcoin blockchain but are in reality a integral part of the process of acquiring and using Bitcoins. Daniel Leisegang provides some additional details:
Nicht die (Noten-)Banken, sondern die technischen Strukturen sollen also das Vertrauen in die Digitalwährung begründen. Dieses Versprechen ist jedoch überaus zweifelhaft. Denn in den vergangenen Jahren verloren zahlreiche Bitcoin-Nutzerinnen und -Nutzer Millionen an Euro – unter anderem, weil Cyberkriminelle Programmierfehler ausnutzten. So wurde im August 2016 die Bitcoin-Börse Bitfinex gehackt und um rund 58 Mio. Euro erleichtert. Bereits gut zwei Jahre zuvor – im Februar 2014 – vermeldete die in Tokio ansässige Handelsplattform Mt. Gox den Diebstahl von Bitcoins im Wert von damals 480 Mio. Euro. Als das Unternehmen kurz darauf Konkurs anmeldete, verloren die Nutzer ihr dort noch verbliebenes Geld endgültig.

[Not the (cash-) banks but rather the technical structures should be the basis of trust in the digital currencies. Nevertheless, this promise is very much doubtful. Because in past years, numerous Bitcoin users lost millions of euros - among other things, because cyber-criminals exploited program flaws. So in August 2016, the Bitcoin stock market Bitfinex was hacked and around 50 million euros were lifted. Already two years earlier - in Feburary 2014 - the Tokyo-based trading platform Mt. Gox reported the theft of Bitcoins valued at 480 million euros. When the businesspeople shortly thereafter filed for bankruptcy, the users ultimately lost their money remaining there.]
The economics behind the whole thing are pretty shaky. Some libertarians were enthusiastic about cryptocurrencies because it seemed to be in line with their free-market faith and offered the possibility of a currency independent of governments. The possibility of using them to evade taxes and otherwise break the law might possibly contribute to their enthusiasm. And since libertarians often seem to be goldbugs, the possible similar functions of cryptocurrencies to the gold standard may be part of the attraction.

Bitcoin isn't based on any material standard or government guarantee. But it does have built-in limits to the number of Bitcoins that can be created.

And how are they created? The process is called "mining." Yes, mining. The "miners" have to set up new Bitcoins through a complex process of calculation and verification within the Bitcoin blockchain. Leisegang writes, New Bitcoins have, because of that [the complex creation process] come to be generated almost exclusively in giant commercial computer centers - the so-called Mining Pools. ("Neue Bitcoins werden daher inzwischen fast ausschließlich in riesigen, kommerziellen Rechenzentren generiert – den sogenannten Mining Pools.")

If you are wondering how that affects the libertarian goal of a decentralized currency, you're asking the right kind of question. According to Leisegang, four large mining organizations are doing around 70% of the Bitcoin mining. This kind of concentration offers easier opportunities for theft or hacking.

Aside from monopoly power, the mining process also uses a surprisingly large amount of energy power. As Leisegand explains, this is part of the reason that more than half of the Bitcoins are mined in China, which has relatively cheap power available. (China is reportedly putting new restrictions on the use of Bitcoin.)

Bitcoin also has restrictions built in that limits each round of Bitcoin mining to a smaller number of Bitcoins than the preceding one. Which means that eventually, the mining process hits a limit at which no more Bitcoins could be created. And that kind of restriction on the available currency units could have a similar effect to the same kind of limitation imposed by the gold standard. Lipton and Pentland explain:

[Bitcoin] also has serious logistical constraints. For example, the number of transactions that can be handled per second is approximately seven, compared with the 2,000 on average handled by Visa. It’s an energy suck, too: mining — the process by which nodes of the cryptocurrency network compete to securely add new transactions to the blockchain—depends on a huge amount of electricity. In high energy-cost countries, miners go bust if they cannot afford the utility bills for the computing power. While exact numbers are not known, it is believed that Bitcoin consumes as much electricity as eBay, Facebook and Google combined. [my emphasis]
Frances Coppola has been a critic and skeptic of the Bitcoin craze. She states her perspective succinctly in the following tweet. The "Lightning" to which she refers is another kind of software solution that aspires to allow Bitcoin to overcome some of its current limitations:

She discusses the Lightning network in more detail in Probability for geeks Coppola Comment 01/09/2018.