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Cryptocurrency | A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it. It is a decentralized system for verifying that the parties to a transaction have the money they claim to have, eliminating the need for traditional intermediaries, such as banks, when funds are being transferred between two entities.Individual coin ownership records are stored in a digital ledger, which is a computerized database using strong cryptography to secure transaction records, control the creation of additional coins, and verify the transfer of coin ownership. Despite their name, cryptocurrencies are not considered to be currencies in the traditional sense, and while varying treatments have been applied to them, including classification as commodities, securities, and currencies, cryptocurrencies are generally viewed as a distinct asset class in practice. Some crypto schemes use validators to maintain the cryptocurrency. In a proof-of-stake model, owners put up their tokens as collateral. In return, they get authority over the token in proportion to the amount they stake. Generally, these token stakers get additional ownership in the token over time via network fees, newly minted tokens, or other such reward mechanisms.Cryptocurrency does not exist in physical form (like paper money) and is typically not issued by a central authority. Cryptocurrencies typically use decentralized control as opposed to a central bank digital currency (CBDC). When a cryptocurrency is minted, created prior to issuance, or issued by a single issuer, it is generally considered centralized. When implemented with decentralized control, each cryptocurrency works through distributed ledger technology, typically a blockchain, that serves as a public financial transaction database.The first cryptocurrency was Bitcoin, which was first released as open-source software in 2009. As of June 2023, there were more than 25,000 other cryptocurrencies in the marketplace, of which more than 40 had a market capitalization exceeding $1 billion.
== History ==
In 1983, American cryptographer David Chaum conceived of a type of cryptographic electronic money called ecash. Later, in 1995, he implemented it through Digicash, an early form of cryptographic electronic payments. Digicash required user software in order to withdraw notes from a bank and designate specific encrypted keys before it can be sent to a recipient. This allowed the digital currency to be untraceable by a third party.
In 1996, the National Security Agency published a paper entitled How to Make a Mint: The Cryptography of Anonymous Electronic Cash, describing a cryptocurrency system. The paper was first published in an MIT mailing list and later in 1997 in The American Law Review.In 1998, Wei Dai described "b-money", an anonymous, distributed electronic cash system. Shortly thereafter, Nick Szabo described bit gold. Like Bitcoin and other cryptocurrencies that would follow it, bit gold (not to be confused with the later gold-based exchange BitGold) was described as an electronic currency system which required users to complete a proof of work function with solutions being cryptographically put together and published.
In January 2009, Bitcoin was created by pseudonymous developer Satoshi Nakamoto. It used SHA-256, a cryptographic hash function, in its proof-of-work scheme. In April 2011, Namecoin was created as an attempt at forming a decentralized DNS. In October 2011, Litecoin was released which used scrypt as its hash function instead of SHA-256. Peercoin, created in August 2012, used a hybrid of proof-of-work and proof-of-stake.
Cryptocurrency has undergone several periods of growth and retraction, including several bubbles and market crashes, such as in 2011, 2013-2014–15, 2017-2018 and 2021–2023.On 6 August 2014, the UK announced its Treasury had commissioned a study of cryptocurrencies, and what role, if any, they could play in the UK economy. The study was also to report on whether regulation should be considered. Its final report was published in 2018, and it issued a consultation on cryptoassets and stablecoins in January 2021.In June 2021, El Salvador became the first country to accept Bitcoin as legal tender, after the Legislative Assembly had voted 62–22 to pass a bill submitted by President Nayib Bukele classifying the cryptocurrency as such.In August 2021, Cuba followed with Resolution 215 to recognize and regulate cryptocurrencies such as Bitcoin.In September 2021, the government of China, the single largest market for cryptocurrency, declared all cryptocurrency transactions illegal. This completed a crackdown on cryptocurrency that had previously banned the operation of intermediaries and miners within China.On 15 September 2022, the world's second largest cryptocurrency at that time, Ethereum transitioned its consensus mechanism from proof-of-work (PoW) to proof-of-stake (PoS) in an upgrade process known as "the Merge". According to the Ethereum Founder, the upgrade can cut both Ethereum's energy use and carbon-dioxide emissions by 99.9%.On 11 November 2022, FTX Trading Ltd., a cryptocurrency exchange, which also operated a crypto hedge fund, and had been valued at $18 billion, filed for bankruptcy. The financial impact of the collapse extended beyond the immediate FTX customer base, as reported, while, at a Reuters conference, financial industry executives said that "regulators must step in to protect crypto investors." Technology analyst Avivah Litan commented on the cryptocurrency ecosystem that "everything...needs to improve dramatically in terms of user experience, controls, safety, customer service."
== Formal definition ==
According to Jan Lansky, a cryptocurrency is a system that meets six conditions:
The system does not require a central authority; its state is maintained through distributed consensus.
The system keeps an overview of cryptocurrency units and their ownership.
The system defines whether new cryptocurrency units can be created. If new cryptocurrency units can be created, the system defines the circumstances of their origin and how to determine the ownership of these new units.
Ownership of cryptocurrency units can be proved exclusively cryptographically.
The system allows transactions to be performed in which ownership of the cryptographic units is changed. A transaction statement can only be issued by an entity proving the current ownership of these units.
If two different instructions for changing the ownership of the same cryptographic units are simultaneously entered, the system performs at most one of them.In March 2018, the word cryptocurrency was added to the Merriam-Webster Dictionary.
=== Altcoins ===
Tokens, cryptocurrencies, and other digital assets other than Bitcoin are collectively known as alternative cryptocurrencies, typically shortened to "altcoins" or "alt coins", or disparagingly "shitcoins". Paul Vigna of The Wall Street Journal also described altcoins as "alternative versions of Bitcoin" given its role as the model protocol for altcoin designers.
Altcoins often have underlying differences when compared to Bitcoin. For example, Litecoin aims to process a block every 2.5 minutes, rather than Bitcoin's 10 minutes, which allows Litecoin to confirm transactions faster than Bitcoin. Another example is Ethereum, which has smart contract functionality that allows decentralized applications to be run on its blockchain. Ethereum was the most used blockchain in 2020, according to Bloomberg News. In 2016, it had the largest "following" of any altcoin, according to the New York Times.Significant rallies across altcoin markets are often referred to as an "altseason".
==== Stablecoins ====
Stablecoins are cryptocurrencies designed to maintain a stable level of purchasing power. Notably, these designs are not foolproof, as a number of stablecoins have crashed or lost their peg. For example, on 11 May 2022, Terra's stablecoin UST fell from $1 to 26 cents. The subsequent failure of Terraform Labs resulted in the loss of nearly $40B invested in the Terra and Luna coins. In September 2022, South Korean prosecutors requested the issuance of an Interpol Red Notice against the company's founder, Do Kwon. In Hong Kong, the expected regulatory framework for stablecoins in 2023/24 is being shaped and includes a few considerations.
== Architecture ==
Cryptocurrency is produced by an entire cryptocurrency system collectively, at a rate which is defined when the system is created and which is publicly stated. In centralized banking and economic systems such as the US Federal Reserve System, corporate boards or governments control the supply of currency. In the case of cryptocurrency, companies or governments cannot produce new units, and have not so far provided backing for other firms, banks or corporate entities which hold asset value measured in it. The underlying technical system upon which cryptocurrencies are based was created by Satoshi Nakamoto.Within a proof-of-work system such as Bitcoin, the safety, integrity and balance of ledgers is maintained by a community of mutually distrustful parties referred to as miners. Miners use their computers to help validate and timestamp transactions, adding them to the ledger in accordance with a particular timestamping scheme. In a proof-of-stake blockchain, transactions are validated by holders of the associated cryptocurrency, sometimes grouped together in stake pools.
Most cryptocurrencies are designed to gradually decrease the production of that currency, placing a cap on the total amount of that currency that will ever be in circulation. Compared with ordinary currencies held by financial institutions or kept as cash on hand, cryptocurrencies can be more difficult for seizure by law enforcement.
=== Blockchain ===
The validity of each cryptocurrency's coins is provided by a blockchain. A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a hash pointer as a link to a previous block, a timestamp and transaction data. By design, blockchains are inherently resistant to modification of the data. It is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way". For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority.
Blockchains are secure by design and are an example of a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain.
=== Nodes ===
A node is a computer that connects to a cryptocurrency network. The node supports the cryptocurrency's network through either relaying transactions, validation, or hosting a copy of the blockchain. In terms of relaying transactions, each network computer (node) has a copy of the blockchain of the cryptocurrency it supports. When a transaction is made, the node creating the transaction broadcasts details of the transaction using encryption to other nodes throughout the node network so that the transaction (and every other transaction) is known.
Node owners are either volunteers, those hosted by the organization or body responsible for developing the cryptocurrency blockchain network technology, or those who are enticed to host a node to receive rewards from hosting the node network.
==== Timestamping ====
Cryptocurrencies use various timestamping schemes to "prove" the validity of transactions added to the blockchain ledger without the need for a trusted third party.
The first timestamping scheme invented was the proof-of-work scheme. The most widely used proof-of-work schemes are based on SHA-256 and scrypt.Some other hashing algorithms that are used for proof-of-work include CryptoNote, Blake, SHA-3, and X11.
Another method is called the proof-of-stake scheme. Proof-of-stake is a method of securing a cryptocurrency network and achieving distributed consensus through requesting users to show ownership of a certain amount of currency. It is different from proof-of-work systems that run difficult hashing algorithms to validate electronic transactions. The scheme is largely dependent on the coin, and there is currently no standard form of it. Some cryptocurrencies use a combined proof-of-work and proof-of-stake scheme.
=== Mining ===
On a blockchain, mining is the validation of transactions. For this effort, successful miners obtain new cryptocurrency as a reward. The reward decreases transaction fees by creating a complementary incentive to contribute to the processing power of the network. The rate of generating hashes, which validate any transaction, has been increased by the use of specialized machines such as FPGAs and ASICs running complex hashing algorithms like SHA-256 and scrypt. This arms race for cheaper-yet-efficient machines has existed since Bitcoin was introduced in 2009. Mining is measured by hash rate typically in TH/s.With more people venturing into the world of virtual currency, generating hashes for validation has become more complex over time, forcing miners to invest increasingly large sums of money to improve computing performance. Consequently, the reward for finding a hash has diminished and often does not justify the investment in equipment and cooling facilities (to mitigate the heat the equipment produces), and the electricity required to run them. Popular regions for mining include those with inexpensive electricity, a cold climate, and jurisdictions with clear and conducive regulations. By July 2019, Bitcoin's electricity consumption was estimated to be approximately 7 gigawatts, around 0.2% of the global total, or equivalent to the energy consumed nationally by Switzerland.Some miners pool resources, sharing their processing power over a network to split the reward equally, according to the amount of work they contributed to the probability of finding a block. A "share" is awarded to members of the mining pool who present a valid partial proof-of-work.
As of February 2018, the Chinese Government has halted trading of virtual currency, banned initial coin offerings and shut down mining. Many Chinese miners have since relocated to Canada and Texas. One company is operating data centers for mining operations at Canadian oil and gas field sites, due to low gas prices. In June 2018, Hydro Quebec proposed to the provincial government to allocate 500 megawatts of power to crypto companies for mining. According to a February 2018 report from Fortune, Iceland has become a haven for cryptocurrency miners in part because of its cheap electricity.In March 2018, the city of Plattsburgh, New York put an 18-month moratorium on all cryptocurrency mining in an effort to preserve natural resources and the "character and direction" of the city. In 2021, Kazakhstan became the second-biggest crypto-currency mining country, producing 18.1% of the global exahash rate. The country built a compound containing 50,000 computers near Ekibastuz.
==== GPU price rise ====
An increase in cryptocurrency mining increased the demand for graphics cards (GPU) in 2017. The computing power of GPUs makes them well-suited to generating hashes. Popular favorites of cryptocurrency miners such as Nvidia's GTX 1060 and GTX 1070 graphics cards, as well as AMD's RX 570 and RX 580 GPUs, doubled or tripled in price – or were out of stock. A GTX 1070 Ti which was released at a price of $450 sold for as much as $1,100. Another popular card, the GTX 1060 (6 GB model) was released at an MSRP of $250, and sold for almost $500. RX 570 and RX 580 cards from AMD were out of stock for almost a year. Miners regularly buy up the entire stock of new GPU's as soon as they are available.Nvidia has asked retailers to do what they can when it comes to selling GPUs to gamers instead of miners. Boris Böhles, PR manager for Nvidia in the German region, said: "Gamers come first for Nvidia."
==== Mining accelerator chips ====
Numerous companies developed dedicated crypto-mining accelerator chips, capable of price-performance far higher than that of CPU or GPU mining. At one point Intel marketed its own brand of crypto accelerator chip, named Blockscale.
=== Wallets ===
A cryptocurrency wallet is a means of storing the public and private "keys" (address) or seed which can be used to receive or spend the cryptocurrency. With the private key, it is possible to write in the public ledger, effectively spending the associated cryptocurrency. With the public key, it is possible for others to send currency to the wallet.
There exist multiple methods of storing keys or seed in a wallet. These methods range from using paper wallets (which are public, private or seed keys written on paper), to using hardware wallets (which are hardware to store your wallet information), to a digital wallet (which is a computer with a software hosting your wallet information), to hosting your wallet using an exchange where cryptocurrency is traded, or by storing your wallet information on a digital medium such as plaintext.
=== Anonymity ===
Bitcoin is pseudonymous, rather than anonymous; the cryptocurrency in a wallet is not tied to a person, but rather to one or more specific keys (or "addresses"). Thereby, Bitcoin owners are not immediately identifiable, but all transactions are publicly available in the blockchain. Still, cryptocurrency exchanges are often required by law to collect the personal information of their users.Some cryptocurrencies, such as Monero, Zerocoin, Zerocash, and CryptoNote, implement additional measures to increase privacy, such as by using zero-knowledge proofs.A recent 2020 study presented different attacks on privacy in cryptocurrencies. The attacks demonstrated how the anonymity techniques are not sufficient safeguards. In order to improve privacy, researchers suggested several different ideas including new cryptographic schemes and mechanisms for hiding the IP address of the source.
== Economics ==
Cryptocurrencies are used primarily outside banking and governmental institutions and are exchanged over the Internet.
=== Block rewards ===
Proof-of-work cryptocurrencies, such as Bitcoin, offer block rewards incentives for miners. There has been an implicit belief that whether miners are paid by block rewards or transaction fees does not affect the security of the blockchain, but a study suggests that this may not be the case under certain circumstances.The rewards paid to miners increase the supply of the cryptocurrency. By making sure that verifying transactions is a costly business, the integrity of the network can be preserved as long as benevolent nodes control a majority of computing power. The verification algorithm requires a lot of processing power, and thus electricity in order to make verification costly enough to accurately validate public blockchain. Not only do miners have to factor in the costs associated with expensive equipment necessary to stand a chance of solving a hash problem, they further must consider the significant amount of electrical power in search of the solution. Generally, the block rewards outweigh electricity and equipment costs, but this may not always be the case.The current value, not the long-term value, of the cryptocurrency supports the reward scheme to incentivize miners to engage in costly mining activities. In 2018, Bitcoin's design caused a 1.4% welfare loss compared to an efficient cash system, while a cash system with 2% money growth has a minor 0.003% welfare cost. The main source for this inefficiency is the large mining cost, which is estimated to be US$360 million per year. This translates into users being willing to accept a cash system with an inflation rate of 230% before being better off using Bitcoin as a means of payment. However, the efficiency of the Bitcoin system can be significantly improved by optimizing the rate of coin creation and minimizing transaction fees. Another potential improvement is to eliminate inefficient mining activities by changing the consensus protocol altogether.
=== Transaction fees ===
Transaction fees for cryptocurrency depend mainly on the supply of network capacity at the time, versus the demand from the currency holder for a faster transaction. The currency holder can choose a specific transaction fee, while network entities process transactions in order of highest offered fee to lowest. Cryptocurrency exchanges can simplify the process for currency holders by offering priority alternatives and thereby determine which fee will likely cause the transaction to be processed in the requested time.For Ethereum, transaction fees differ by computational complexity, bandwidth use, and storage needs, while Bitcoin transaction fees differ by transaction size and whether the transaction uses SegWit. In February 2023, the median transaction fee for Ether corresponded to $2.2845, while for Bitcoin it corresponded to $0.659.Some cryptocurrencies have no transaction fees, and instead rely on client-side proof-of-work as the transaction prioritization and anti-spam mechanism.
=== Exchanges ===
Cryptocurrency exchanges allow customers to trade cryptocurrencies for other assets, such as conventional fiat money, or to trade between different digital currencies.
Crypto marketplaces do not guarantee that an investor is completing a purchase or trade at the optimal price. As a result, as of 2020 it was possible to arbitrage to find the difference in price across several markets.
=== Atomic swaps ===
Atomic swaps are a mechanism where one cryptocurrency can be exchanged directly for another cryptocurrency, without the need for a trusted third party such as an exchange.
=== ATMs ===
Jordan Kelley, founder of Robocoin, launched the first Bitcoin ATM in the United States on 20 February 2014. The kiosk installed in Austin, Texas, is similar to bank ATMs but has scanners to read government-issued identification such as a driver's license or a passport to confirm users' identities.
=== Initial coin offerings ===
An initial coin offering (ICO) is a controversial means of raising funds for a new cryptocurrency venture. An ICO may be used by startups with the intention of avoiding regulation. However, securities regulators in many jurisdictions, including in the U.S., and Canada, have indicated that if a coin or token is an "investment contract" (e.g., under the Howey test, i.e., an investment of money with a reasonable expectation of profit based significantly on the entrepreneurial or managerial efforts of others), it is a security and is subject to securities regulation. In an ICO campaign, a percentage of the cryptocurrency (usually in the form of "tokens") is sold to early backers of the project in exchange for legal tender or other cryptocurrencies, often Bitcoin or Ether.According to PricewaterhouseCoopers, four of the 10 biggest proposed initial coin offerings have used Switzerland as a base, where they are frequently registered as non-profit foundations. The Swiss regulatory agency FINMA stated that it would take a "balanced approach" to ICO projects and would allow "legitimate innovators to navigate the regulatory landscape and so launch their projects in a way consistent with national laws protecting investors and the integrity of the financial system." In response to numerous requests by industry representatives, a legislative ICO working group began to issue legal guidelines in 2018, which are intended to remove uncertainty from cryptocurrency offerings and to establish sustainable business practices.
=== Price trends ===
The market capitalization of a cryptocurrency is calculated by multiplying the price by the number of coins in circulation. The total cryptocurrency market cap has historically been dominated by Bitcoin accounting for at least 50% of the market cap value where altcoins have increased and decreased in market cap value in relation to Bitcoin. Bitcoin's value is largely determined by speculation among other technological limiting factors known as blockchain rewards coded into the architecture technology of Bitcoin itself. The cryptocurrency market cap follows a trend known as the "halving", which is when the block rewards received from Bitcoin are halved due to technological mandated limited factors instilled into Bitcoin which in turn limits the supply of Bitcoin. As the date reaches near of a halving (twice thus far historically) the cryptocurrency market cap increases, followed by a downtrend.By June 2021, cryptocurrency had begun to be offered by some wealth managers in the US for 401(k)s.
=== Volatility ===
Cryptocurrency prices are much more volatile than established financial assets such as stocks. For example, over one week in May 2022, Bitcoin lost 20% of its value and Ethereum lost 26%, while Solana and Cardano lost 41% and 35% respectively. The falls were attributed to warnings about inflation. By comparison, in the same week, the Nasdaq tech stock index fell 7.6 per cent and the FTSE 100 was 3.6 per cent down.In the longer term, of the 10 leading cryptocurrencies identified by the total value of coins in circulation in January 2018, only four (Bitcoin, Ethereum, Cardano and Ripple (XRP)) were still in that position in early 2022. The total value of all cryptocurrencies was $2 trillion at the end of 2021, but had halved nine months later. The Wall Street Journal has commented that the crypto sector has become "intertwined" with the rest of the capital markets and "sensitive to the same forces that drive tech stocks and other risk assets", such as inflation forecasts.
=== Databases ===
There are also centralized databases, outside of blockchains, that store crypto market data. Compared to the blockchain, databases perform fast as there is no verification process. Four of the most popular cryptocurrency market databases are CoinMarketCap, CoinGecko, BraveNewCoin, and Cryptocompare.
== Social and political aspects ==
According to Alan Feuer of The New York Times, libertarians and anarcho-capitalists were attracted to the philosophical idea behind Bitcoin. Early Bitcoin supporter Roger Ver said: "At first, almost everyone who got involved did so for philosophical reasons. We saw Bitcoin as a great idea, as a way to separate money from the state." Economist Paul Krugman argues that cryptocurrencies like Bitcoin are "something of a cult" based in "paranoid fantasies" of government power.David Golumbia says that the ideas influencing Bitcoin advocates emerge from right-wing extremist movements such as the Liberty Lobby and the John Birch Society and their anti-Central Bank rhetoric, or, more recently, Ron Paul and Tea Party-style libertarianism. Steve Bannon, who owns a "good stake" in Bitcoin, sees cryptocurrency as a form of disruptive populism, taking control back from central authorities.Bitcoin's founder, Satoshi Nakamoto, has supported the idea that cryptocurrencies go well with libertarianism. "It's very attractive to the libertarian viewpoint if we can explain it properly," Nakamoto said in 2008.According to the European Central Bank, the decentralization of money offered by Bitcoin has its theoretical roots in the Austrian school of economics, especially with Friedrich von Hayek in his book Denationalisation of Money: The Argument Refined, in which Hayek advocates a complete free market in the production, distribution and management of money to end the monopoly of central banks.
== Increasing regulation ==
The rise in the popularity of cryptocurrencies and their adoption by financial institutions has led some governments to assess whether regulation is needed to protect users. The Financial Action Task Force (FATF) has defined cryptocurrency-related services as "virtual asset service providers" (VASPs) and recommended that they be regulated with the same money laundering (AML) and know your customer (KYC) requirements as financial institutions.In May 2020, the Joint Working Group on interVASP Messaging Standards published "IVMS 101", a universal common language for communication of required originator and beneficiary information between VASPs. The FATF and financial regulators were informed as the data model was developed.In June 2020, FATF updated its guidance to include the "Travel Rule" for cryptocurrencies, a measure which mandates that VASPs obtain, hold, and exchange information about the originators and beneficiaries of virtual asset transfers. Subsequent standardized protocol specifications recommended using JSON for relaying data between VASPs and identity services. As of December 2020, the IVMS 101 data model has yet to be finalized and ratified by the three global standard setting bodies that created it.The European Commission published a digital finance strategy in September 2020. This included a draft regulation on Markets in Crypto-Assets (MiCA), which aimed to provide a comprehensive regulatory framework for digital assets in the EU.On 10 June 2021, the Basel Committee on Banking Supervision proposed that banks that held cryptocurrency assets must set aside capital to cover all potential losses. For instance, if a bank were to hold Bitcoin worth $2 billion, it would be required to set aside enough capital to cover the entire $2 billion. This is a more extreme standard than banks are usually held to when it comes to other assets. However, this is a proposal and not a regulation.
The IMF is seeking a coordinated, consistent and comprehensive approach to supervising cryptocurrencies. Tobias Adrian, the IMF's financial counsellor and head of its monetary and capital markets department said in a January 2022 interview that "Agreeing global regulations is never quick. But if we start now, we can achieve the goal of maintaining financial stability while also enjoying the benefits which the underlying technological innovations bring,"
=== United States ===
In 2021, 17 states passed laws and resolutions concerning cryptocurrency regulation. The U.S. Securities and Exchange Commission (SEC) is considering what steps to take. On 8 July 2021, Senator Elizabeth Warren, part of the Senate Banking Committee, wrote to the chairman of the SEC and demanded answers on cryptocurrency regulation due to the increase in cryptocurrency exchange use and the danger this posed to consumers. On 5 August 2021, SEC Chairman Gary Gensler responded to Senator Elizabeth Warren's letter regarding cryptocurrency regulation and called for legislation focused on "crypto trading, lending and DeFi platforms," because of how vulnerable the investors could be when they traded on crypto trading platforms without a broker. He also argued that many tokens in the crypto market may be unregistered securities without required disclosures or market oversight. Additionally, Gensler did not hold back in his criticism of stablecoins. These tokens, which are pegged to the value of fiat currencies, may allow individuals to bypass important public policy goals related to traditional banking and financial systems, such as anti-money laundering, tax compliance, and sanctions.On 19 October 2021, the first bitcoin-linked exchange-traded fund (ETF) from ProShares started trading on the NYSE under the ticker "BITO." ProShares CEO Michael L. Sapir said the ETF would expose Bitcoin to a wider range of investors without the hassle of setting up accounts with cryptocurrency providers. Ian Balina, the CEO of Token Metrics, stated that the approval of the "BITO" ETF by the SEC was a significant endorsement for the crypto industry because many regulators globally were not in favor of crypto as well as the hesitance to accept crypto from retail investors. This event would eventually open more opportunities for new capital and new people in this space.The United States Department of the Treasury, on 20 May 2021, announced that it would require any transfer worth $10,000 or more to be reported to the Internal Revenue Service since cryptocurrency already posed a problem where illegal activity like tax evasion was facilitated broadly. This release from the IRS was a part of efforts to promote better compliance and consider more severe penalties for tax evaders.On 17 February 2022, the Justice department named Eun Young Choi as the first director of a National Cryptocurrency Enforcement Team to aid in identification of and dealing with misuse of cryptocurrencies and other digital assets.The Biden administration faced a dilemma as it tried to develop regulations for the cryptocurrency industry. On one hand, officials were hesitant to restrict the growing and profitable industry. On the other hand, they were committed to preventing illegal cryptocurrency transactions. To reconcile these conflicting goals, on 9 March 2022, President Biden issued an executive order. Followed by the executive order, on 16 September 2022, the Comprehensive Framework for Responsible Development of Digital Assets document was released to support development of cryptocurrencies and restrict their illegal use. The executive order included all digital assets, but cryptocurrencies posed both the greatest security risks and potential economic benefits. Though this might not address all of the challenges in crypto industry, it was a significant milestone in the U.S. cryptocurrency regulation history.In February 2023, the Securities and Exchange Commission (SEC) ruled that cryptocurrency exchange Kraken's estimated $42 billion in staked assets globally operated as an illegal securities seller. The company agreed to a $30 million settlement with the SEC and to cease selling its staking service in the U.S. The case would impact other major crypto exchanges operating staking programs.On 23 March 2023, the U.S. Securities and Exchange Commission (SEC) issued an alert to investors stating that firms offering crypto asset securities may not be complying with U.S. laws. The SEC stated that unregistered offerings of crypto asset securities may not include important information.
=== China ===
In September 2017, China banned ICOs to cause abnormal return from cryptocurrency decreasing during announcement window. The liquidity changes by banning ICOs in China was temporarily negative while the liquidity effect became positive after news.On 18 May 2021, China banned financial institutions and payment companies from being able to provide cryptocurrency transaction related services. This led to a sharp fall in the price of the biggest proof of work cryptocurrencies. For instance, Bitcoin fell 31%, Ethereum fell 44%, Binance Coin fell 32% and Dogecoin fell 30%. Proof of work mining was the next focus, with regulators in popular mining regions citing the use of electricity generated from highly polluting sources such as coal to create Bitcoin and Ethereum.In September 2021, the Chinese government declared all cryptocurrency transactions of any kind illegal, completing its crackdown on cryptocurrency.
=== United Kingdom ===
In the United Kingdom, as of 10 January 2021, all cryptocurrency firms, such as exchanges, advisors and professionals that have either a presence, market product or provide services within the UK market must register with the Financial Conduct Authority. Additionally, on 27 June 2021, the financial watchdog demanded that Binance, the world's largest cryptocurrency exchange, cease all regulated activities in the UK.
=== South Africa ===
South Africa, which has seen a large number of scams related to cryptocurrency, is said to be putting a regulatory timeline in place that will produce a regulatory framework. The largest scam occurred in April 2021, where the two founders of an African-based cryptocurrency exchange called Africrypt, Raees Cajee and Ameer Cajee, disappeared with $3.8 billion worth of Bitcoin. Additionally, Mirror Trading International disappeared with $170 million worth of cryptocurrency in January 2021.
=== South Korea ===
In March 2021, South Korea implemented new legislation to strengthen their oversight of digital assets. This legislation requires all digital asset managers, providers and exchanges to be registered with the Korea Financial Intelligence Unit in order to operate in South Korea. Registering with this unit requires that all exchanges are certified by the Information Security Management System and that they ensure all customers have real name bank accounts. It also requires that the CEO and board members of the exchanges have not been convicted of any crimes and that the exchange holds sufficient levels of deposit insurance to cover losses arising from hacks.
=== Turkey ===
On 30 April 2021, the Central Bank of the Republic of Turkey banned the use of cryptocurrencies and cryptoassets for making purchases on the grounds that the use of cryptocurrencies for such payments poses significant transaction risks.
=== El Salvador ===
On 9 June 2021, El Salvador announced that it will adopt Bitcoin as legal tender, becoming the first country to do so.
=== India ===
At present, India neither prohibits nor allows investment in the cryptocurrency market. In 2020, the Supreme Court of India had lifted the ban on cryptocurrency, which was imposed by the Reserve Bank of India. Since then, an investment in cryptocurrency is considered legitimate, though there is still ambiguity about the issues regarding the extent and payment of tax on the income accrued thereupon and also its regulatory regime. But it is being contemplated that the Indian Parliament will soon pass a specific law to either ban or regulate the cryptocurrency market in India. Expressing his public policy opinion on the Indian cryptocurrency market to a well-known online publication, a leading public policy lawyer and Vice President of SAARCLAW (South Asian Association for Regional Co-operation in Law) Hemant Batra has said that the "cryptocurrency market has now become very big with involvement of billions of dollars in the market hence, it is now unattainable and irreconcilable for the government to completely ban all sorts of cryptocurrency and its trading and investment". He mooted regulating the cryptocurrency market rather than completely banning it. He favoured following IMF and FATF guidelines in this regard.
=== Switzerland ===
Switzerland was one of the first countries to implement the FATF's Travel Rule. FINMA, the Swiss regulator, issued its own guidance to VASPs in 2019. The guidance followed the FATF's Recommendation 16, however with stricter requirements. According to FINMA's requirements, VASPs need to verify the identity of the beneficiary of the transfer.
== Legality ==
The legal status of cryptocurrencies varies substantially from country to country and is still undefined or changing in many of them. At least one study has shown that broad generalizations about the use of Bitcoin in illicit finance are significantly overstated and that blockchain analysis is an effective crime fighting and intelligence gathering tool. While some countries have explicitly allowed their use and trade, others have banned or restricted it. According to the Library of Congress in 2021,
an "absolute ban" on trading or using cryptocurrencies applies in 9 countries:
Algeria, Bangladesh, Bolivia, China, Egypt, Iraq, Morocco, Nepal, and the United Arab Emirates. An "implicit ban" applies in another 39 countries or regions, which include: Bahrain, Benin, Burkina Faso, Burundi, Cameroon, Chad, Cote d’Ivoire, the Dominican Republic, Ecuador, Gabon, Georgia, Guyana, Indonesia, Iran, Jordan, Kazakhstan, Kuwait, Lebanon, Lesotho, Macau, Maldives, Mali, Moldova, Namibia, Niger, Nigeria, Oman, Pakistan, Palau, Republic of Congo, Saudi Arabia, Sengeal, Tajikistan, Tanzania, Togo, Turkey, Turkmenistan, Qatar and Vietnam. In the United States and Canada, state and provincial securities regulators, coordinated through the North American Securities Administrators Association, are investigating "Bitcoin scams" and ICOs in 40 jurisdictions.Various government agencies, departments, and courts have classified Bitcoin differently. China Central Bank banned the handling of Bitcoins by financial institutions in China in early 2014.
In Russia, though owning cryptocurrency is legal, its residents are only allowed to purchase goods from other residents using the Russian ruble while nonresidents are allowed to use foreign currency. Regulations and bans that apply to Bitcoin probably extend to similar cryptocurrency systems.In August 2018, the Bank of Thailand announced its plans to create its own cryptocurrency, the Central Bank Digital Currency (CBDC).
=== Advertising bans ===
Cryptocurrency advertisements have been banned on the following platforms:
Google - Ended August 2021
Twitter
Facebook - Ended December 2021
Bing - Ended June 2022
Snapchat
LinkedIn
MailChimp
Baidu
Tencent
Weibo
Line
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=== U.S. tax status ===
On 25 March 2014, the United States Internal Revenue Service (IRS) ruled that Bitcoin will be treated as property for tax purposes. Therefore, virtual currencies are considered commodities subject to capital gains tax.
=== Legal concerns relating to an unregulated global economy ===
As the popularity and demand for online currencies has increased since the inception of Bitcoin in 2009, so have concerns that such an unregulated person to person global economy that cryptocurrencies offer may become a threat to society. Concerns abound that altcoins may become tools for anonymous web criminals.Cryptocurrency networks display a lack of regulation that has been criticized as enabling criminals who seek to evade taxes and launder money. Money laundering issues are also present in regular bank transfers, however with bank-to-bank wire transfers for instance, the account holder must at least provide a proven identity.
Transactions that occur through the use and exchange of these altcoins are independent from formal banking systems, and therefore can make tax evasion simpler for individuals. Since charting taxable income is based upon what a recipient reports to the revenue service, it becomes extremely difficult to account for transactions made using existing cryptocurrencies, a mode of exchange that is complex and difficult to track.Systems of anonymity that most cryptocurrencies offer can also serve as a simpler means to launder money. Rather than laundering money through an intricate net of financial actors and offshore bank accounts, laundering money through altcoins can be achieved through anonymous transactions.Cryptocurrency makes legal enforcement against extremist groups more complicated, which consequently strengthens them. White supremacist Richard Spencer went as far as to declare Bitcoin the "currency of the alt-right".
=== Loss, theft, and fraud ===
In February 2014, the world's largest Bitcoin exchange, Mt. Gox, declared bankruptcy. Likely due to theft, the company claimed that it had lost nearly 750,000 Bitcoins belonging to their clients. This added up to approximately 7% of all Bitcoins in existence, worth a total of $473 million. Mt. Gox blamed hackers, who had exploited the transaction malleability problems in the network. The price of a Bitcoin fell from a high of about $1,160 in December to under $400 in February.On 21 November 2017, Tether announced that it had been hacked, losing $31 million in USDT from its core treasury wallet.On 7 December 2017, Slovenian cryptocurrency exchange Nicehash reported that hackers had stolen over $70M using a hijacked company computer.On 19 December 2017, Yapian, the owner of South Korean exchange Youbit, filed for bankruptcy after suffering two hacks that year. Customers were still granted access to 75% of their assets.
In May 2018, Bitcoin Gold had its transactions hijacked and abused by unknown hackers. Exchanges lost an estimated $18m and Bitcoin Gold was delisted from Bittrex after it refused to pay its share of the damages.
On 13 September 2018, Homero Josh Garza was sentenced to 21 months of imprisonment, followed by three years of supervised release. Garza had founded the cryptocurrency startups GAW Miners and ZenMiner in 2014, acknowledged in a plea agreement that the companies were part of a pyramid scheme, and pleaded guilty to wire fraud in 2015. The U.S. Securities and Exchange Commission separately brought a civil enforcement action against Garza, who was eventually ordered to pay a judgment of $9.1 million plus $700,000 in interest. The SEC's complaint stated that Garza, through his companies, had fraudulently sold "investment contracts representing shares in the profits they claimed would be generated" from mining.In January 2018, Japanese exchange Coincheck reported that hackers had stolen $530M worth of cryptocurrencies.In June 2018, South Korean exchange Coinrail was hacked, losing over $37M worth of cryptos. The hack worsened an already ongoing cryptocurrency selloff by an additional $42 billion.On 9 July 2018, the exchange Bancor, whose code and fundraising had been subjects of controversy, had $23.5 million in cryptocurrency stolen.A 2020 EU report found that users had lost crypto-assets worth hundreds of millions of US dollars in security breaches at exchanges and storage providers. Between 2011 and 2019, reported breaches ranged from four to twelve a year. In 2019, more than a billion dollars worth of cryptoassets was reported stolen. Stolen assets "typically find their way to illegal markets and are used to fund further criminal activity".According to a 2020 report produced by the United States Attorney General's Cyber-Digital Task Force, the following three categories make up the majority of illicit cryptocurrency uses: "(1) financial transactions associated with the commission of crimes; (2) money laundering and the shielding of legitimate activity from tax, reporting, or other legal requirements; or (3) crimes, such as theft, directly implicating the cryptocurrency marketplace itself." The report concludes that "for cryptocurrency to realize its truly transformative potential, it is imperative that these risks be addressed" and that "the government has legal and regulatory tools available at its disposal to confront the threats posed by cryptocurrency's illicit uses".According to the UK 2020 national risk assessment—a comprehensive assessment of money laundering and terrorist financing risk in the UK—the risk of using cryptoassets such as Bitcoin for money laundering and terrorism financing is assessed as "medium" (from "low" in the previous 2017 report). Legal scholars suggested that the money laundering opportunities may be more perceived than real. Blockchain analysis company Chainalysis concluded that illicit activities like cybercrime, money laundering and terrorism financing made up only 0.15% of all crypto transactions conducted in 2021, representing a total of $14 billion.In December 2021, Monkey Kingdom, a NFT project based in Hong Kong, lost US$1.3 million worth of cryptocurrencies via a phishing link used by the hacker.
=== Money laundering ===
According to blockchain data company Chainalysis, criminals laundered US$8,600,000,000 worth of cryptocurrency in 2021, up by 30% from the previous year. The data suggests that rather than managing numerous illicit havens, cybercriminals make use of a small group of purpose built centralized exchanges for sending and receiving illicit cryptocurrency. In 2021, those exchanges received 47% of funds sent by crime linked addresses. Almost $2.2bn worth of cryptocurrencies was embezzled from DeFi protocols in 2021, which represents 72% of all cryptocurrency theft in 2021.
According to Bloomberg and the New York Times, Federation Tower, a two skyscraper complex in the heart of Moscow City, is home to many cryptocurrency businesses under suspicion of facilitating extensive money laundering, including accepting illicit cryptocurrency funds obtained through scams, darknet markets, and ransomware. Notable businesses include Garantex, Eggchange, Cashbank, Buy-Bitcoin, Tetchange, Bitzlato, and Suex, which was sanctioned by the U.S. in 2021. Bitzlato founder and owner Anatoly Legkodymov was arrested following money-laundering charges by the United States Department of Justice.Dark money has also been flowing into Russia through a dark web marketplace called Hydra, which is powered by cryptocurrency, and enjoyed more than $1 billion in sales in 2020, according to Chainalysis. The platform demands that sellers liquidate cryptocurrency only through certain regional exchanges, which has made it difficult for investigators to trace the money.
Almost 74% of ransomware revenue in 2021 — over $400 million worth of cryptocurrency — went to software strains likely affiliated with Russia, where oversight is notoriously limited. However, Russians are also leaders in the benign adoption of cryptocurrencies, as the ruble is unreliable, and President Putin favours the idea of "overcoming the excessive domination of the limited number of reserve currencies."In 2022, RenBridge - an unregulated alternative to exchanges for transferring value between blockchains - was found to be responsible for the laundering of at least $540 million since 2020. It is especially popular with people attempting to launder money from theft. This includes a cyberattack on Japanese crypto exchange Liquid that has been linked to North Korea.
=== Darknet markets ===
Properties of cryptocurrencies gave them popularity in applications such as a safe haven in banking crises and means of payment, which also led to the cryptocurrency use in controversial settings in the form of online black markets, such as Silk Road. The original Silk Road was shut down in October 2013 and there have been two more versions in use since then. In the year following the initial shutdown of Silk Road, the number of prominent dark markets increased from four to twelve, while the amount of drug listings increased from 18,000 to 32,000.Darknet markets present challenges in regard to legality. Cryptocurrency used in dark markets are not clearly or legally classified in almost all parts of the world. In the U.S., Bitcoins are labelled as "virtual assets". This type of ambiguous classification puts pressure on law enforcement agencies around the world to adapt to the shifting drug trade of dark markets.
=== Wash trades ===
Various studies have found that crypto-trading is rife with wash trading. Wash trading is a process, illegal in some jurisdictions, involving buyers and sellers being the same person or group, and may be used to manipulate the price of a cryptocurrency or inflate volume artificially. Exchanges with higher volumes can demand higher premiums from token issuers. A study from 2019 concluded that up to 80% of trades on unregulated cryptocurrency exchanges could be wash trades. A 2019 report by Bitwise Asset Management claimed that 95% of all Bitcoin trading volume reported on major website CoinMarketCap had been artificially generated, and of 81 exchanges studied, only 10 provided legitimate volume figures.
=== As a tool to evade sanctions ===
In 2022, cryptocurrencies attracted attention when Western nations imposed severe economic sanctions on Russia in the aftermath of its invasion of Ukraine in February. However, American sources warned in March that some crypto-transactions could potentially be used to evade economic sanctions against Russia and Belarus.In April 2022, the computer programmer Virgil Griffith received a five-year prison sentence in the US for attending a Pyongyang cryptocurrency conference, where he gave a presentation on blockchains which might be used for sanctions evasion.
== Impacts and analysis ==
The Bank for International Settlements summarized several criticisms of cryptocurrencies in Chapter V of their 2018 annual report. The criticisms include the lack of stability in their price, the high energy consumption, high and variable transactions costs, the poor security and fraud at cryptocurrency exchanges, vulnerability to debasement (from forking), and the influence of miners.
=== Speculation, fraud, and adoption ===
Cryptocurrencies have been compared to Ponzi schemes, pyramid schemes and economic bubbles, such as housing market bubbles. Howard Marks of Oaktree Capital Management stated in 2017 that digital currencies were "nothing but an unfounded fad (or perhaps even a pyramid scheme), based on a willingness to ascribe value to something that has little or none beyond what people will pay for it", and compared them to the tulip mania (1637), South Sea Bubble (1720), and dot-com bubble (1999), which all experienced profound price booms and busts.Regulators in several countries have warned against cryptocurrency and some have taken measures to dissuade users. However, research in 2021 by the UK's financial regulator suggests such warnings either went unheard, or were ignored. Fewer than one in 10 potential cryptocurrency buyers were aware of consumer warnings on the FCA website, and 12% of crypto users were not aware that their holdings were not protected by statutory compensation. Of 1,000 respondents between the ages of eighteen and forty, almost 70% falsely assumed cryptocurrencies were regulated, 75% of younger crypto investors claimed to be driven by competition with friends and family, 58% said that social media enticed them to make high risk investments. The FCA recommends making use of its warning list, which flags unauthorized financial firms.Many banks do not offer virtual currency services themselves and can refuse to do business with virtual currency companies. In 2014, Gareth Murphy, a senior banking officer, suggested that the widespread adoption of cryptocurrencies may lead to too much money being obfuscated, blinding economists who would use such information to better steer the economy. While traditional financial products have strong consumer protections in place, there is no intermediary with the power to limit consumer losses if Bitcoins are lost or stolen. One of the features cryptocurrency lacks in comparison to credit cards, for example, is consumer protection against fraud, such as chargebacks.
The French regulator Autorité des marchés financiers (AMF) lists 16 websites of companies that solicit investment in cryptocurrency without being authorized to do so in France.An October 2021 paper by the National Bureau of Economic Research found that Bitcoin suffers from systemic risk as the top 10,000 addresses control about one-third of all Bitcoin in circulation. It is even worse for Bitcoin miners, with 0.01% controlling 50% of the capacity. According to researcher Flipside Crypto, less than 2% of anonymous accounts control 95% of all available Bitcoin supply. This is considered risky as a great deal of the market is in the hands of a few entities.
A paper by John Griffin, a finance professor at the University of Texas, and Amin Shams, a graduate student found that in 2017 the price of Bitcoin had been substantially inflated using another cryptocurrency, Tether.Roger Lowenstein, author of "Bank of America: The Epic Struggle to Create the Federal Reserve," says in a New York Times story that FTX will face over $8 billion in claims.
=== Non-fungible tokens ===
Non-fungible tokens (NFTs) are digital assets that represent art, collectibles, gaming, etc. Like crypto, their data is stored on the blockchain. NFTs are bought and traded using cryptocurrency. The Ethereum blockchain was the first place where NFTs were implemented, but now many other blockchains have created their own versions of NFTs.
=== Banks ===
As the first big Wall Street bank to embrace cryptocurrencies, Morgan Stanley announced on 17 March 2021 that they will be offering access to Bitcoin funds for their wealthy clients through three funds which enable Bitcoin ownership for investors with an aggressive risk tolerance. BNY Mellon on 11 February 2021 announced that it would begin offering cryptocurrency services to its clients.On 20 April 2021, Venmo added support to its platform to enable customers to buy, hold and sell cryptocurrencies.In October 2021, financial services company Mastercard announced it is working with digital asset manager Bakkt on a platform that would allow any bank or merchant on the Mastercard network to offer cryptocurrency services.
=== Environmental effects ===
Mining for proof-of-work cryptocurrencies requires enormous amounts of electricity and consequently comes with a large carbon footprint due to causing greenhouse gas emissions. Proof-of-work blockchains such as Bitcoin, Ethereum, Litecoin, and Monero were estimated to have added between 3 million and 15 million tons of carbon dioxide (CO2) to the atmosphere in the period from 1 January 2016 to 30 June 2017. By November 2018, Bitcoin was estimated to have an annual energy consumption of 45.8TWh, generating 22.0 to 22.9 million tons of CO2, rivalling nations like Jordan and Sri Lanka. By the end of 2021, Bitcoin was estimated to produce 65.4 million tons of CO2, as much as Greece, and consume between 91 and 177 terawatt-hours annually.Critics have also identified a large electronic waste problem in disposing of mining rigs. Mining hardware is improving at a fast rate, quickly resulting in older generations of hardware.Bitcoin is the least energy-efficient cryptocurrency, using 707.6 kilowatt-hours of electricity per transaction.Before June 2021, China was the primary location for Bitcoin mining. However, due to concerns over power usage and other factors, China forced out Bitcoin operations, at least temporarily. As a result, the United States promptly emerged as the top global leader in the industry. An example of a gross amount of electronic waste associated with Bitcoin mining operations in the US is a facility that located in Dalton, Georgia which is consuming nearly the same amount of electricity as the combined power usage of 97,000 households in its vicinity. Another example is that Riot Platforms operates a Bitcoin mining facility in Rockdale, Texas, which consumes approximately as much electricity as the nearby 300,000 households. This makes it the most energy-intensive Bitcoin mining operation in the United States.The world's second-largest cryptocurrency, Ethereum, uses 62.56 kilowatt-hours of electricity per transaction. XRP is the world's most energy efficient cryptocurrency, using 0.0079 kilowatt-hours of electricity per transaction.Although the biggest PoW blockchains consume energy on the scale of medium-sized countries, the annual power demand from proof-of-stake (PoS) blockchains is on a scale equivalent to a housing estate. The Times identified six "environmentally friendly" cryptocurrencies: Chia, IOTA, Cardano, Nano, Solarcoin and Bitgreen. Academics and researchers have used various methods for estimating the energy use and energy efficiency of blockchains. A study of the six largest proof-of-stake networks in May 2021 concluded:
Cardano has the lowest electricity use per node;
Polkadot has the lowest electricity use overall; and
Solana has the lowest electricity use per transaction.In terms of annual consumption (kWh/yr), the figures were: Polkadot (70,237), Tezos (113,249), Avalanche (489,311), Algorand (512,671), Cardano (598,755) and Solana (1,967,930). This equates to Polkadot consuming 7 times the electricity of an average U.S. home, Cardano 57 homes and Solana 200 times as much. The research concluded that PoS networks consumed 0.001% the electricity of the Bitcoin network. University College London researchers reached a similar conclusion.Variable renewable energy power stations could invest in Bitcoin mining to reduce curtailment, hedge electricity price risk, stabilize the grid, increase the profitability of renewable energy power stations and therefore accelerate transition to sustainable energy.
=== Technological limitations ===
There are also purely technical elements to consider. For example, technological advancement in cryptocurrencies such as Bitcoin result in high up-front costs to miners in the form of specialized hardware and software. Cryptocurrency transactions are normally irreversible after a number of blocks confirm the transaction. Additionally, cryptocurrency private keys can be permanently lost from local storage due to malware, data loss or the destruction of the physical media. This precludes the cryptocurrency from being spent, resulting in its effective removal from the markets.
=== Academic studies ===
In September 2015, the establishment of the peer-reviewed academic journal Ledger (ISSN 2379-5980) was announced. It covers studies of cryptocurrencies and related technologies, and is published by the University of Pittsburgh.The journal encourages authors to digitally sign a file hash of submitted papers, which will then be timestamped into the Bitcoin blockchain. Authors are also asked to include a personal Bitcoin address in the first page of their papers.
=== Aid agencies ===
A number of aid agencies have started accepting donations in cryptocurrencies, including UNICEF. Christopher Fabian, principal adviser at UNICEF Innovation, said the children's fund would uphold donor protocols, meaning that people making donations online would have to pass checks before they were allowed to deposit funds.However, in 2021, there was a backlash against donations in Bitcoin because of the environmental emissions it caused. Some agencies stopped accepting Bitcoin and others turned to "greener" cryptocurrencies. The U.S. arm of Greenpeace stopped accepting bitcoin donations after seven years. It said: "As the amount of energy needed to run Bitcoin became clearer, this policy became no longer tenable."In 2022, the Ukrainian government raised over US$10,000,000 worth of aid through cryptocurrency following the 2022 Russian invasion of Ukraine.
=== Criticism ===
Bitcoin has been characterized as a speculative bubble by eight winners of the Nobel Memorial Prize in Economic Sciences: Paul Krugman, Robert J. Shiller, Joseph Stiglitz, Richard Thaler, James Heckman, Thomas Sargent, Angus Deaton, and Oliver Hart; and by central bank officials including Alan Greenspan, Agustín Carstens, Vítor Constâncio, and Nout Wellink.Investors Warren Buffett and George Soros have respectively characterized it as a "mirage" and a "bubble"; while business executives Jack Ma and JP Morgan Chase CEO Jamie Dimon have called it a "bubble" and a "fraud", respectively, although Jamie Dimon later said he regretted dubbing Bitcoin a fraud. BlackRock CEO Laurence D. Fink called Bitcoin an "index of money laundering".In June 2022, business magnate Bill Gates said that cryptocurrencies are "100% based on greater fool theory".Legal scholars criticize the lack of regulation, which hinders conflict resolution when crypto assets are at the center of a legal dispute, for example a divorce or an inheritance. In Switzerland, jurists generally deny that cryptocurrencies are objects that fall under property law, as cryptocurrencies do not belong to any class of legally defined objects (Typenzwang, the legal numerus clausus). Therefore, it is debated whether anybody could even be sued for embezzlement of cryptocurrency if he/she had access to someone's wallet. However, in the law of obligations and contract law, any kind of object would be legally valid, but the object would have to be tied to an identified counterparty. However, as the more popular cryptocurrencies can be freely and quickly exchanged into legal tender, they are financial assets and have to be taxed and accounted for as such.In 2018, an increase in crypto-related suicides was noticed after the cryptocurrency market crashed in August. The situation was particularly critical in Korea as crypto traders were on "suicide watch". A cryptocurrency forum on Reddit even started providing suicide prevention support to affected investors. The May 2022 collapse of the Luna currency operated by Terra also led to reports of suicidal investors in crypto-related subreddits.
== See also ==
== Notes ==
== References ==
== Further reading ==
Chayka, Kyle (2 July 2013). "What Comes After Bitcoin?". Pacific Standard. Retrieved 18 January 2014.
Guadamuz, Andres; Marsden, Chris (2015). "Blockchains and Bitcoin: Regulatory responses to cryptocurrencies" (PDF). First Monday. 20 (12). doi:10.5210/fm.v20i12.6198. S2CID 811921.
== External links ==
Media related to Cryptocurrency at Wikimedia Commons
Quotations related to Cryptocurrency at Wikiquote
Learning materials related to Should cryptocurrencies be banned? at Wikiversity |
Bitcoin | Bitcoin (abbreviation: BTC or XBT; sign: ₿) is the first decentralized cryptocurrency. Nodes in the peer-to-peer bitcoin network verify transactions through cryptography and record them in a public distributed ledger, called a blockchain, without central oversight.
Consensus between nodes is achieved using a computationally intensive system based on proof-of-work called mining. Bitcoin mining requires increasing quantities of electricity and was responsible for 0.2% of world greenhouse gas emissions as of 2022.Based on a free market ideology, bitcoin was invented in 2008 by Satoshi Nakamoto, an unknown person. Use of bitcoin as a currency began in 2009, with the release of its open-source implementation.: ch. 1 In 2021, El Salvador adopted it as legal tender. Bitcoin is currently used more as a store of value and less as a medium of exchange or unit of account. It is mostly seen as an investment and has been described by many scholars as an economic bubble. As bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by several countries as of 2021.
== History ==
=== Background ===
Before bitcoin, several digital cash technologies were released, starting with David Chaum's ecash in the 1980s. The idea that solutions to computational puzzles could have some value was first proposed by cryptographers Cynthia Dwork and Moni Naor in 1992. The concept was independently rediscovered by Adam Back who developed Hashcash, a proof-of-work scheme for spam control in 1997. The first proposals for distributed digital scarcity-based cryptocurrencies came from cypherpunks Wei Dai (b-money) and Nick Szabo (bit gold) in 1998. In 2004, Hal Finney developed the first currency based on reusable proof-of-work. These various attempts were not successful: Chaum's concept required centralized control and no banks wanted to sign on, Hashcash had no protection against double-spending, while b-money and bit gold were not resistant to Sybil attacks.
=== 2008–2009: Creation ===
The domain name bitcoin.org was registered on 18 August 2008. On 31 October 2008, a link to a white paper authored by Satoshi Nakamoto titled Bitcoin: A Peer-to-Peer Electronic Cash System was posted to a cryptography mailing list. Nakamoto implemented the bitcoin software as open-source code and released it in January 2009. Nakamoto's identity remains unknown. All individual components of bitcoin originated in earlier academic literature. Nakamoto's innovation was their complex interplay resulting in the first decentralized, Sybil resistant, Byzantine fault tolerant digital cash system, that would eventually be referred to as the first blockchain. Nakamoto's paper was not peer-reviewed and initially ignored by academics, who argued that it could not work, based on theoretical models, even though it was working in practice.On 3 January 2009, the bitcoin network was created when Nakamoto mined the starting block of the chain, known as the genesis block. Embedded in this block was the text "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks", which is the date and headline of an issue of The Times newspaper. Nine days later, Hal Finney received the first bitcoin transaction: ten bitcoins from Nakamoto. Wei Dai and Nick Szabo were also early supporters. In 2010, the first known commercial transaction using bitcoin occurred when programmer Laszlo Hanyecz bought two Papa John's pizzas for ₿10,000.
=== 2010–2012: Early growth ===
Blockchain analysts estimate that Nakamoto had mined about one million bitcoins before disappearing in 2010 when he handed the network alert key and control of the code repository over to Gavin Andresen. Andresen later became lead developer at the Bitcoin Foundation, an organization founded in September 2012 to promote bitcoin.After early "proof-of-concept" transactions, the first major users of bitcoin were black markets, such as the dark web Silk Road. During its 30 months of existence, beginning in February 2011, Silk Road exclusively accepted bitcoins as payment, transacting ₿9.9 million, worth about $214 million.: 222
=== 2013–2014: First regulatory actions ===
In March 2013, the US Financial Crimes Enforcement Network (FinCEN) established regulatory guidelines for "decentralized virtual currencies" such as bitcoin, classifying American bitcoin miners who sell their generated bitcoins as money services businesses, subject to registration and other legal obligations. In May 2013, US authorities seized the unregistered exchange Mt. Gox. In June 2013, the US Drug Enforcement Administration seized ₿11.02 from a man attempting to use them to buy illegal substances. This marked the first time a government agency had seized bitcoins. The FBI seized about ₿30,000 in October 2013 from Silk Road, following the arrest of its founder Ross Ulbricht.In December 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoin. After the announcement, the value of bitcoin dropped, and Baidu no longer accepted bitcoins for certain services. Buying real-world goods with any virtual currency had been illegal in China since at least 2009.
=== 2015–2019 ===
Research produced by the University of Cambridge estimated that in 2017, there were 2.9 to 5.8 million unique users using a cryptocurrency wallet, most of them using bitcoin. In August 2017, the SegWit software upgrade was activated. Segwit was intended to support the Lightning Network as well as improve scalability. SegWit opponents, who supported larger blocks as a scalability solution, forked to create Bitcoin Cash, one of many forks of bitcoin.In February 2018, price crashed after China imposed a complete ban on Bitcoin trading. The percentage of bitcoin trading in the Chinese renminbi fell from over 90% in September 2017 to less than 1% in June 2018. During the same year, Bitcoin prices were negatively affected by several hacks or thefts from cryptocurrency exchanges.
=== 2020–present ===
In 2020, some major companies and institutions started to acquire bitcoin: MicroStrategy invested $250 million in bitcoin as a treasury reserve asset, Square, Inc., $50 million, and MassMutual, $100 million. In November 2020, PayPal added support for bitcoin in the US.In February 2021, Bitcoin's market capitalization reached $1 trillion for the first time. In November 2021, the Taproot soft-fork upgrade was activated, adding support for Schnorr signatures, improved functionality of smart contracts and Lightning Network. Before, Bitcoin only used a custom elliptic curve with the ECDSA algorithm to produce signatures.: 101 In September 2021, Bitcoin became legal tender in El Salvador, alongside the US dollar.In May and June 2022, the bitcoin price fell following the collapses of TerraUSD, a stablecoin, and the Celsius Network, a decentralized finance loan company.In 2023, ordinals, non-fungible tokens (NFTs) on Bitcoin, went live.
== Design ==
=== Units and divisibility ===
The unit of account of the bitcoin system is the bitcoin. It is represented with the currency codes BTC and XBT as well as the symbol ₿.
No uniform capitalization convention exists; some sources use Bitcoin, capitalized, to refer to the technology and network, and bitcoin, lowercase, for the unit of account. The Oxford English Dictionary advocates the use of lowercase bitcoin in all cases.One bitcoin is divisible to eight decimal places.: ch. 5 Units for smaller amounts of bitcoin are the millibitcoin (mBTC), equal to 1⁄1000 bitcoin, and the satoshi (sat), representing 1⁄100000000 (one hundred millionth) bitcoin, the smallest amount possible. 100,000 satoshis are one mBTC.
=== Blockchain ===
As a decentralized system, bitcoin operates without a central authority or single administrator, so that anyone can create a new bitcoin address and transact without needing any approval.: ch. 1 This is accomplished through a specialized distributed ledger called a blockchain that records bitcoin transactions.The blockchain is implemented as an ordered list of blocks. Each block contains a SHA-256 hash of the previous block, "chaining" them in chronological order.: ch. 7 The blockchain is maintained by a peer-to-peer network.: 215–219 Individual blocks, public addresses, and transactions within blocks are public information, and can be examined using a blockchain explorer.Nodes validate and broadcast transactions, each maintaining a copy of the blockchain for ownership verification. A new block is created every 10 minutes on average, updating the blockchain across all nodes without central oversight. This process tracks bitcoin spending, ensuring each bitcoin is spent only once. Unlike a traditional ledger that tracks physical currency, bitcoins exist digitally as unspent outputs of transactions.: ch. 5
=== Addresses and transactions ===
In the blockchain, bitcoins are linked to specific addresses that are hashes of a public key. Creating an address involves generating a random private key and then computing the corresponding address. This process is almost instant, but the reverse (finding the private key for a given address) is nearly impossible.: ch. 4 Publishing a bitcoin address does not risk its private key, and it is extremely unlikely to accidentally generate a used key with funds. To use bitcoins, owners need their private key to digitally sign transactions, which are verified by the network using the public key, keeping the private key secret.: ch. 5 Bitcoin transactions use a Forth-like scripting language,: ch. 5 involving one or more inputs and outputs. When sending bitcoins, a user specifies the recipients' addresses and the amount for each output. This allows sending bitcoins to several recipients in a single transaction. To prevent double-spending, each input must refer to a previous unspent output in the blockchain. Using multiple inputs is similar to using multiple coins in a cash transaction. As in a cash transaction, the sum of inputs can exceed the intended sum of payments. In such a case, an additional output can return the change back to the payer. Unallocated input satoshis in the transaction become the transaction fee.Losing a private key means losing access to the bitcoins, with no other proof of ownership accepted by the protocol. For instance, in 2013, a user lost ₿7,500, valued at US$7.5 million, by accidentally discarding a hard drive with the private key. It is estimated that around 20% of all bitcoins are lost. The private key must also be kept secret as its exposure, such as through a data breach, can lead to theft of the associated bitcoins.: ch. 10 As of December 2017, approximately ₿980,000 had been stolen from cryptocurrency exchanges.
=== Mining ===
The mining process in Bitcoin involves maintaining the blockchain through computer processing power. Miners group and broadcast new transactions into blocks, which are then verified by the network. Each block must contain a proof-of-work (PoW) to be accepted, involving finding a nonce number that, combined with the block content, produces a hash numerically smaller than the network's difficulty target.: ch. 8 This PoW is simple to verify but hard to generate, requiring many attempts.: ch. 8 PoW forms the basis of Bitcoin's consensus mechanism.The difficulty of generating a block is deterministically adjusted based on the mining power on the network by changing the difficulty target, which is recalibrated every 2,016 blocks (approximately two weeks) to maintain an average time of ten minutes between new blocks. The process requires significant computational power and specialized hardware.: ch. 8 Miners who successfully find a new block can collect transaction fees from the included transactions and a set reward in bitcoins. To claim this reward, a special transaction called a coinbase is included in the block, with the miner as the payee. All bitcoins in existence have been created through this type of transaction.: ch. 8 This reward is halved every 210,000 blocks until ₿21 million, with new bitcoin issuance slated to end around 2140. Afterward, miners will only earn from transaction fees. These fees are determined by the transaction's size and the amount of data stored, measured in satoshis per byte.: ch. 8 The proof-of-work system and the chaining of blocks make blockchain modifications very difficult, as altering one block requires changing all subsequent blocks. As more blocks are added, modifying older blocks becomes increasingly challenging. In case of disagreement, nodes trust the longest chain, which required the greatest amount of effort to produce. To tamper or censor the ledger, one needs to control the majority of the global hashrate. The high cost required to reach this level of computational power guarantees the security of the bitcoin blockchain.Bitcoin mining's environmental impact is significant and has attracted the attention of regulators, leading to restrictions or bans in various jurisdictions. As of 2022, bitcoin mining is estimated to represent 0.4% of global electricity consumption and to be responsible for 0.2% of world greenhouse gas emissions, as about half of the electricity used is generated through fossil fuels. Moreover, mining hardware's short lifespan results in electronic waste. The amount of electrical energy and e-waste generated by bitcoin mining is often compared with countries like Greece or the Netherlands.
=== Privacy and fungibility ===
Bitcoin is pseudonymous, with funds linked to addresses, not real-world identities. While the owners of these addresses are not directly identified, all transactions are public on the blockchain. Patterns of use, like spending coins from multiple inputs, can hint at a common owner. Public data can sometimes be matched with known address owners. Bitcoin exchanges might also need to collect personal data as per legal requirements. For enhanced privacy, users can generate a new address for each transaction.In the Bitcoin network, each bitcoin is treated equally, ensuring basic fungibility. However, users and applications can choose to differentiate between bitcoins. While wallets and software treat all bitcoins the same, each bitcoin's transaction history is recorded on the blockchain. This public record allows for chain analysis, where users can identify and potentially reject bitcoins from controversial sources. For example, in 2012, Mt. Gox froze accounts containing bitcoins identified as stolen.
=== Wallets ===
Bitcoin wallets were the first cryptocurrency wallets, enabling users to store the information necessary to transact bitcoins.: ch. 1, glossary The first wallet program, simply named Bitcoin, and sometimes referred to as the Satoshi client, was released in 2009 by Nakamoto as open-source software. Bitcoin Core is among the best known clients. Forks of Bitcoin Core exist such as Bitcoin Unlimited. Wallets can be full clients, with a full copy of the blockchain to check the validity of mined blocks,: ch. 1 or lightweight clients, just to send and receive transactions without a local copy of the entire blockchain. Third-party internet services called online wallets store users' credentials on their servers, making them susceptible of hacks. "Cold storage" protects bitcoins from such hacks by keeping private keys offline, either through specialized hardware wallets or paper printouts.: ch. 4
=== Scalability and decentralization challenges ===
Nakamoto limited the block size to one megabyte. The limited block size and frequency can lead to delayed processing of transactions, increased fees and a Bitcoin scalability problem. The Lightning Network, second-layer routing network, is a potential scaling solution.: ch. 8 Research shows a trend towards centralization in bitcoin as miners join pools for stable income.: 215, 219–222 : 3 If a single miner or pool controls more than 50% of the hashing power, it would allow them to censor transactions and double-spend coins. In 2014, mining pool Ghash.io reached 51% mining power, causing safety concerns, but later voluntarily capped its power at 39.99% for the benefit of the whole network. A few entities also dominate other parts of the ecosystem such as the client software, online wallets, and simplified payment verification (SPV) clients.
== Economics and usage ==
=== Bitcoin's theoretical roots and ideology ===
According to the European Central Bank, the decentralization of money offered by bitcoin has its theoretical roots in the Austrian school of economics, especially with Friedrich von Hayek's book The Denationalization of Money, in which he advocates a complete free market in the production, distribution and management of money to end the monopoly of central banks.: 22 Sociologist Nigel Dodd, citing the crypto-anarchist Declaration of Bitcoin's Independence, argues that the essence of the bitcoin ideology is to remove money from social, as well as governmental, control. The Economist describes bitcoin as "a techno-anarchist project to create an online version of cash, a way for people to transact without the possibility of interference from malicious governments or banks". These philosophical ideas initially attracted libertarians and anarchists. Economist Paul Krugman argues that cryptocurrencies like bitcoin are only used by bank skeptics and criminals.
=== Recognition as a currency and legal status ===
Money serves three purposes: a store of value, a medium of exchange, and a unit of account. According to The Economist in 2014, bitcoin functions best as a medium of exchange. In 2015, The Economist noted that bitcoins had three qualities useful in a currency: they are "hard to earn, limited in supply and easy to verify". However, a 2018 assessment by The Economist stated that cryptocurrencies met none of these three criteria. Per some researchers, as of 2015, bitcoin functions more as a payment system than as a currency. In 2014, economist Robert J. Shiller wrote that bitcoin has potential as a unit of account for measuring the relative value of goods, as with Chile's Unidad de Fomento, but that "Bitcoin in its present form ... doesn't really solve any sensible economic problem". François R. Velde, Senior Economist at the Chicago Fed, described bitcoin as "an elegant solution to the problem of creating a digital currency". David Andolfatto, Vice President at the Federal Reserve Bank of St. Louis, stated that bitcoin is a threat to the establishment, which he argues is a good thing for the Federal Reserve System and other central banks, because it prompts these institutions to operate sound policies.The legal status of bitcoin varies substantially from one jurisdiction to another. Because of its decentralized nature and its global presence, regulating bitcoin is difficult. However, the use of bitcoin can be criminalized, and shutting down exchanges and the peer-to-peer economy in a given country would constitute a de facto ban. The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, and law enforcement. Nobel-prize winning economist Joseph Stiglitz says that bitcoin's anonymity encourages money laundering and other crimes. This is the main justification behind bitcoin bans. As of November 2021, nine countries applied an absolute ban (Algeria, Bangladesh, China, Egypt, Iraq, Morocco, Nepal, Qatar, and Tunisia) while another 42 countries had an implicit ban. Bitcoin is only legal tender in El Salvador.
=== Use for payments ===
As of 2018, Bitcoin is rarely used in transactions with merchants, but it is popular to purchase illegal goods online. Prices are not usually quoted in bitcoin and trades involve conversions into fiat currencies. Commonly cited reasons for not using Bitcoin include high costs, the inability to process chargebacks, high price volatility, long transaction times, transaction fees (especially for small purchases). Bloomberg reported that bitcoin was being used for large-item purchases on the site Overstock.com and for cross-border payments to freelancers. As of 2015, there was little sign of bitcoin use in international remittances despite high fees charged by banks and Western Union who compete in this market.In September 2021, the Bitcoin Law made bitcoin legal tender in El Salvador, alongside the US dollar. The adoption has been criticized both internationally and within El Salvador. In particular, in 2022, the International Monetary Fund (IMF) urged El Salvador to reverse its decision. As of 2022, the use of Bitcoin in El Salvador remains low: 80% of businesses refused to accept it despite being legally required to. In April 2022, the Central African Republic (CAR) adopted Bitcoin as legal tender alongside the CFA franc, but repealed the reform one year later.Bitcoin is also used by some governments. For instance, the Iranian government initially opposed cryptocurrencies, but later saw them as an opportunity to circumvent sanctions. Since 2020, Iran has required local bitcoin miners to sell bitcoin to the Central Bank of Iran, allowing the central bank to use it for imports. Some constituent states also accept tax payments in bitcoin, including Colorado (US) and Zug (Switzerland).
=== Use for investment and status as an economic bubble ===
As of 2018, the overwhelming majority of bitcoin transactions took place on cryptocurrency exchanges. Since 2014, regulated bitcoin funds also allow exposure to the asset or to futures as an investment. Individuals and companies such as the Winklevoss twins and Elon Musk's companies SpaceX and Tesla have massively invested in Bitcoin. Bitcoin wealth is highly concentrated, with 0.01% holding 27% of in-circulation currency, as of 2021. As of September 2023, El Salvador had $76.5 million worth of bitcoin in its international reserves.In 2018, research published in the Journal of Monetary Economics concluded that price manipulation occurred during the Mt. Gox bitcoin theft and that the market remained vulnerable to manipulation. Research published in The Journal of Finance also suggested that trading associated with increases in the amount of the Tether cryptocurrency and associated trading at the Bitfinex exchange accounted for about half of the price increase in bitcoin in late 2017.Bitcoin, along with other cryptocurrencies, has been described as an economic bubble by several economists, including Nobel Prize in Economics laureates, such as Joseph Stiglitz, James Heckman, and Paul Krugman. Another recipient of the prize, Robert Shiller, argues that bitcoin is rather a fad that may become an asset class. He describes its price growth as an "epidemic", driven by contagious narratives.According to research published in the International Review of Financial Analysis in 2018, Bitcoin as an asset is highly volatile and does not behave like any other conventional asset. According to one 2022 analysis published in The Journal of Alternative Investments, bitcoin was less volatile than oil, silver, US Treasuries, and 190 stocks in the S&P 500 during and after the 2020 stock market crash. The term "hodl" was created in December 2013 for holding Bitcoin rather than selling it during periods of volatility.Economists, investors, and the central bank of Estonia have described bitcoin as a potential Ponzi scheme. Legal scholar Eric Posner disagrees as "a real Ponzi scheme takes fraud; bitcoin, by contrast, seems more like a collective delusion." A 2014 World Bank report also concluded that bitcoin was not a deliberate Ponzi scheme.
== See also ==
Alternative currency
== Notes ==
== References ==
== Further reading ==
Nakamoto, Satoshi (31 October 2008). "Bitcoin: A Peer-to-Peer Electronic Cash System" (PDF). bitcoin.org. Archived (PDF) from the original on 20 March 2014. Retrieved 28 April 2014. |
Digital currency | Digital currency (digital money, electronic money or electronic currency) is any currency, money, or money-like asset that is primarily managed, stored or exchanged on digital computer systems, especially over the internet. Types of digital currencies include cryptocurrency, virtual currency and central bank digital currency. Digital currency may be recorded on a distributed database on the internet, a centralized electronic computer database owned by a company or bank, within digital files or even on a stored-value card.Digital currencies exhibit properties similar to traditional currencies, but generally do not have a classical physical form of fiat currency historically that can be held in the hand, like currencies with printed banknotes or minted coins. However, they do have a physical form in an unclassical sense coming from the computer to computer and computer to human interactions and the information and processing power of the servers that store and keep track of money. This unclassical physical form allows nearly instantaneous transactions over the internet and vastly lowers the cost associated with distributing notes and coins: for example, of the types of money in the UK economy, 3% are notes and coins, and 79% as electronic money (in the form of bank deposits). Usually not issued by a governmental body, virtual currencies are not considered a legal tender and they enable ownership transfer across governmental borders.This type of currency may be used to buy physical goods and services, but may also be restricted to certain communities such as for use inside an online game.Digital money can either be centralized, where there is a central point of control over the money supply (for instance, a bank), or decentralized, where the control over the money supply is predetermined or agreed upon democratically.
== History ==
Precursory ideas for digital currencies were presented in electronic payment methods such as the Sabre (travel reservation system). In 1983, a research paper titled "Blind Signatures for Untraceable Payments" by David Chaum introduced the idea of digital cash. In 1989, he founded DigiCash, an electronic cash company, in Amsterdam to commercialize the ideas in his research. It filed for bankruptcy in 1998.e-gold was the first widely used Internet money, introduced in 1996, and grew to several million users before the US Government shut it down in 2008. e-gold has been referenced to as "digital currency" by both US officials and academia. In 1997, Coca-Cola offered buying from vending machines using mobile payments. PayPal launched its USD-denominated service in 1998. In 2009, bitcoin was launched, which marked the start of decentralized blockchain-based digital currencies with no central server, and no tangible assets held in reserve. Also known as cryptocurrencies, blockchain-based digital currencies proved resistant to attempt by government to regulate them, because there was no central organization or person with the power to turn them off.Origins of digital currencies date back to the 1990s Dot-com bubble. Another known digital currency service was Liberty Reserve, founded in 2006; it lets users convert dollars or euros to Liberty Reserve Dollars or Euros, and exchange them freely with one another at a 1% fee. Several digital currency operations were reputed to be used for Ponzi schemes and money laundering, and were prosecuted by the U.S. government for operating without MSB licenses. Q coins or QQ coins, were used as a type of commodity-based digital currency on Tencent QQ's messaging platform and emerged in early 2005. Q coins were so effective in China that they were said to have had a destabilizing effect on the Chinese Yuan currency due to speculation. Recent interest in cryptocurrencies has prompted renewed interest in digital currencies, with bitcoin, introduced in 2008, becoming the most widely used and accepted digital currency.
== Sub-types of digital currency and comparisons ==
=== Digital currency as a specific type and as a meta-group name ===
Digital currency is a term that refers to a specific type of electronic currency with specific properties. Digital currency is also a term used to include the meta-group of sub-types of digital currency, the specific meaning can only be determined within the specific legal or contextual case. Legally and technically, there already are a myriad of legal definitions of digital currency and the many digital currency sub-types. Combining different possible properties, there exists an extensive number of implementations creating many and numerous sub-types of digital currency. Many governmental jurisdictions have implemented their own unique definition for digital currency, virtual currency, cryptocurrency, e-money, network money, e-cash, and other types of digital currency. Within any specific government jurisdiction, different agencies and regulators define different and often conflicting meanings for the different types of digital currency based on the specific properties of a specific currency type or sub-type.
=== Digital versus virtual currency ===
A virtual currency has been defined in 2012 by the European Central Bank as "a type of unregulated, digital money, which is issued and usually controlled by its developers, and used and accepted among the members of a specific virtual community". The US Department of Treasury in 2013 defined it more tersely as "a medium of exchange that operates like a currency in some environments, but does not have all the attributes of real currency". The US Department of Treasury also stated that, "Virtual currency does not have legal-tender status in any jurisdiction."According to the European Central Bank's 2015 "Virtual currency schemes – a further analysis" report, virtual currency is a digital representation of value, not issued by a central bank, credit institution or e-money institution, which, in some circumstances, can be used as an alternative to money. In the previous report of October 2012, the virtual currency was defined as a type of unregulated, digital money, which is issued and usually controlled by its developers, and used and accepted among the members of a specific virtual community.According to the Bank for International Settlements' November 2015 "Digital currencies" report, it is an asset represented in digital form and having some monetary characteristics. Digital currency can be denominated to a sovereign currency and issued by the issuer responsible to redeem digital money for cash. In that case, digital currency represents electronic money (e-money). Digital currency denominated in its own units of value or with decentralized or automatic issuance will be considered as a virtual currency. As such, bitcoin is a digital currency but also a type of virtual currency. Bitcoin and its alternatives are based on cryptographic algorithms, so these kinds of virtual currencies are also called cryptocurrencies.
=== Digital versus cryptocurrency ===
Cryptocurrency is a sub-type of digital currency and a digital asset that relies on cryptography to chain together digital signatures of asset transfers, peer-to-peer networking and decentralization. In some cases a proof-of-work or proof-of-stake scheme is used to create and manage the currency. Cryptocurrencies can allow electronic money systems to be decentralized. When implemented with a blockchain, the digital ledger system or record keeping system uses cryptography to edit separate shards of database entries that are distributed across many separate servers. The first and most popular system is bitcoin, a peer-to-peer electronic monetary system based on cryptography.
=== Digital versus traditional currency ===
Most of the traditional money supply is bank money held on computers. They are considered digital currency in some cases. One could argue that our increasingly cashless society means that all currencies are becoming digital currencies, but they are not presented to us as such.
== Types of systems ==
=== Centralized systems ===
Currency can be exchanged electronically using debit cards and credit cards using electronic funds transfer at point of sale.
==== Mobile digital wallets ====
A number of electronic money systems use contactless payment transfer in order to facilitate easy payment and give the payee more confidence in not letting go of their electronic wallet during the transaction.
In 1994 Mondex and National Westminster Bank provided an "electronic purse" to residents of Swindon
In about 2005 Telefónica and BBVA Bank launched a payment system in Spain called Mobipay which used simple short message service facilities of feature phones intended for pay-as-you-go services including taxis and pre-pay phone recharges via a BBVA current bank account debit.
In January 2010, Venmo launched as a mobile payment system through SMS, which transformed into a social app where friends can pay each other for minor expenses like a cup of coffee, rent and pay a share of the restaurant bill when one has forgotten their wallet. It is popular with college students, but has some security issues. It can be linked to a bank account, credit/debit card or have a loaded value to limit the amount of loss in case of a security breach. Credit cards and non-major debit cards incur a 3% processing fee.
On 19 September 2011, Google Wallet released in the United States to make it easy to carry all one's credit/debit cards on a phone.
In 2012 Ireland's O2 (owned by Telefónica) launched Easytrip to pay road tolls which were charged to the mobile phone account or prepay credit.
The UK's O2 invented O2 Wallet at about the same time. The wallet can be charged with regular bank accounts or cards and discharged by participating retailers using a technique known as 'money messages'. The service closed in 2014.
On 9 September 2014, Apple Pay was announced at the iPhone 6 event. In October 2014 it was released as an update to work on iPhone 6 and Apple Watch. It is very similar to Google Wallet, but for Apple devices only.
==== Central bank digital currency ====
A central bank digital currency (CBDC) is a form of universally accessible digital money in a nation and holds the same value as the country's paper currency. Like a cryptocurrency, a CBCD is held in the form of tokens. CBDCs are different from regular digital cash forms like in online bank accounts because CBDCs are established through the central bank within a country, with liabilities held by one's government, rather than from a commercial bank. Approximately nine countries have already established a CBDC, with interest in the system increasing highly throughout the world. In these nations, CBDCs have been used as a form of exchange and a way for governments to try to prevent risks from occurring within their financial systems.A major problem with central bank digital currencies is deciding whether the currency should be easily trackable. If it's traceable, the government has more control than it currently does. Additionally, there's a technical aspect to consider: whether CBDCs should be based on tokens or accounts and how much anonymity users should have.
=== Decentralized systems ===
Digital Currency has been implemented in some cases as a decentralized system of any combination of currency issuance, ownership record, ownership transfer authorization and validation, and currency storage.
Per the Bank for International Settlements (BIS), "These schemes do not distinguish between users based on location, and
therefore allow value to be transferred between users across borders. Moreover, the speed of a
transaction is not conditional on the location of the payer and payee."
== Law ==
Since 2001, the European Union has implemented the E-Money Directive "on the taking up, pursuit and prudential supervision of the business of electronic money institutions" last amended in 2009.In the United States, electronic money is governed by Article 4A of the Uniform Commercial Code for wholesale transactions and the Electronic Fund Transfer Act for consumer transactions. Provider's responsibility and consumer's liability are regulated under Regulation E.
== Regulation ==
Virtual currencies pose challenges for central banks, financial regulators, departments or ministries of finance, as well as fiscal authorities and statistical authorities.
== Adoption by governments ==
As of 2016, over 24 countries are investing in distributed ledger technologies (DLT) with $1.4bn in investments. In addition, over 90 central banks are engaged in DLT discussions, including implications of a central bank issued digital currency.
Hong Kong's Octopus card system: Launched in 1997 as an electronic purse for public transportation, is the most successful and mature implementation of contactless smart cards used for mass transit payments. After only 5 years, 25 percent of Octopus card transactions are unrelated to transit, and accepted by more than 160 merchants.
London Transport's Oyster card system: Oyster is a plastic smartcard that can hold pay-as-you-go credit, Travelcards and Bus & Tram season tickets. An Oyster card can be used to travel on bus, Tube, tram, DLR, London Overground and most National Rail services in London.
Japan's FeliCa: A contactless RFID smart card, used in a variety of ways such as in ticketing systems for public transportation, e-money, and residence door keys.
The Netherlands' Chipknip: As an electronic cash system used in the Netherlands, all ATM cards issued by the Dutch banks had value that could be loaded via Chipknip loading stations. For people without a bank, pre-paid Chipknip cards could be purchased at various locations in the Netherlands. As of 1 January 2015, payment can no longer be made with Chipknip.
Belgium's Proton: An electronic purse application for debit cards in Belgium. Introduced in February 1995, as a means to replace cash for small transactions. The system was retired on 31 December 2014.In March 2018, the Marshall Islands became the first country to issue their own cryptocurrency and certify it as legal tender; the currency is called the "sovereign".
=== United States of America ===
==== US Commodity Futures Trading Commission guidance ====
The US Commodity Futures Trading Commission (CFTC) has determined virtual currencies are properly defined as commodities in 2015. The CFTC warned investors against pump and dump schemes that use virtual currencies.
==== US Internal Revenue Service guidance ====
The US Internal Revenue Service (IRS) ruling Notice 2014-21 defines any virtual currency, cryptocurrency and digital currency as property; gains and losses are taxable within standard property policies.
==== US Treasury guidance ====
On 20 March 2013, the Financial Crimes Enforcement Network issued a guidance to clarify how the U.S. Bank Secrecy Act applied to persons creating, exchanging, and transmitting virtual currencies.
==== US Securities and Exchange Commission guidance ====
In May 2014 the US Securities and Exchange Commission (SEC) "warned about the hazards of bitcoin and other virtual currencies".
==== New York state regulation ====
In July 2014, the New York State Department of Financial Services proposed the most comprehensive regulation of virtual currencies to date, commonly called BitLicense. It has gathered input from bitcoin supporters and the financial industry through public hearings and a comment period until 21 October 2014 to customize the rules. The proposal per NY DFS press release "sought to strike an appropriate balance that helps protect consumers and root out illegal activity". It has been criticized by smaller companies to favor established institutions, and Chinese bitcoin exchanges have complained that the rules are "overly broad in its application outside the United States".
=== Canada ===
The Bank of Canada has explored the possibility of creating a version of its currency on the blockchain.The Bank of Canada teamed up with the nation's five largest banks – and the blockchain consulting firm R3 – for what was known as Project Jasper. In a simulation run in 2016, the central bank issued CAD-Coins onto a blockchain similar Ethereum. The banks used the CAD-Coins to exchange money the way they do at the end of each day to settle their master accounts.
=== China ===
In 2016, Fan Yifei, a deputy governor of China's central bank, the People's Bank of China (PBOC), wrote that "the conditions are ripe for digital currencies, which can reduce operating costs, increase efficiency and enable a wide range of new applications". According to Fan Yifei, the best way to take advantage of the situation is for central banks to take the lead, both in supervising private digital currencies and in developing digital legal tender of their own.In October 2019, the PBOC announced that a digital renminbi would be released after years of preparation. The version of the currency, known as DCEP (Digital Currency Electronic Payment), is based on cryptocurrency which can be "decoupled" from the banking system. The announcement received a variety of responses: some believe it is more about domestic control and surveillance.In December 2020, the PBOC distributed CN¥20 million worth of digital renminbi to the residents of Suzhou through a lottery program to further promote the government-backed digital currency. Recipients of the currency could make both offline and online purchases, expanding on an earlier trial that did not require internet connection through the inclusion of online stores in the program. Around 20,000 transactions were reported by the e-commerce company JD.com in the first 24 hours of the trial. Contrary to other online payment platforms such as Alipay or WeChat Pay, the digital currency does not have transaction fees.
=== Denmark ===
The Danish government proposed getting rid of the obligation for selected retailers to accept payment in cash, moving the country closer to a "cashless" economy. The Danish Chamber of Commerce is backing the move. Nearly a third of the Danish population uses MobilePay, a smartphone application for transferring money.
=== Ecuador ===
A law passed by the National Assembly of Ecuador gives the government permission to make payments in electronic currency and proposes the creation of a national digital currency. "Electronic money will stimulate the economy; it will be possible to attract more Ecuadorian citizens, especially those who do not have checking or savings accounts and credit cards alone. The electronic currency will be backed by the assets of the Central Bank of Ecuador", the National Assembly said in a statement. In December 2015, Sistema de Dinero Electrónico ("electronic money system") was launched, making Ecuador the first country with a state-run electronic payment system.
=== El Salvador ===
On Jun 9, 2021, the Legislative Assembly of El Salvador has become the first country in the world to officially classify Bitcoin as legal currency. Starting 90 days after approval, every business must accept Bitcoin as legal tender for goods or services, unless it is unable to provide the technology needed to do the transaction.
=== Netherlands ===
The Dutch central bank is experimenting with a blockchain-based virtual currency called "DNBCoin".
=== India ===
The Unified Payments Interface (UPI) is a real-time payment system for instant money transfers between any two bank accounts held in participating banks in India. The interface has been developed by the National Payments Corporation of India and is regulated by the Reserve Bank of India. This digital payment system is available 24 hours a day, every day of the year. UPI is agnostic to the type of user and is used for person to person, person to business, business to person and business to business transactions.
Transactions can be initiated by the payer or the payee. To identify a bank account it uses a unique Virtual Payment Address (VPA) of the type 'accountID@bankID'. The VPA can be assigned by the bank, but can also be self specified just like an email address. The simplest and most common form of VPA is 'mobilenumber@upi'. Money can be transferred from one VPA to another or from one VPA to any bank account in a participating bank using account number and bank branch details. Transfers can be inter-bank or intra-bank.
UPI has no intermediate holding pond for money. It withdraws funds directly from the bank account of the sender and deposits them directly into the recipient's bank account whenever a transaction is requested. A sender can initiate and authorise a transfer using a two step secure process: login using a pass code → initiate → verify using a passcode. A receiver can initiate a payment request on the system to send the payer a notification or by presenting a QR code. On receiving the request, the payer can decline or confirm the payment using the same two step process: login → confirm → verify. The system is extraordinarily user friendly to the extent that even technophobes and barely literate users are adopting it in huge numbers.
=== Russia ===
Government-controlled Sberbank of Russia owns YooMoney – electronic payment service and digital currency of the same name.
=== Sweden ===
Sweden is in the process of replacing all of its physical banknotes, and most of its coins by mid-2017. However, the new banknotes and coins of the Swedish krona will probably be circulating at about half the 2007 peak of 12,494 kronor per capita. The Riksbank is planning to begin discussions of an electronic currency issued by the central bank to which "is not to replace cash, but to act as complement to it". Deputy Governor Cecilia Skingsley states that cash will continue to spiral out of use in Sweden, and while it is currently fairly easy to get cash in Sweden, it is often very difficult to deposit it into bank accounts, especially in rural areas. No decision has been currently made about the decision to create "e-krona".
In her speech, Skingsley states: "The first question is whether e-krona should be booked in accounts or whether the ekrona should be some form of a digitally transferable unit that does not need an underlying account structure, roughly like cash." Skingsley also states: "Another important question is whether the Riksbank should issue e-krona directly to the general public or go via the banks, as we do now with banknotes and coins." Other questions will be addressed like interest rates, should they be positive, negative, or zero?
=== Switzerland ===
In 2016, a city government first accepted digital currency in payment of city fees. Zug, Switzerland, added bitcoin as a means of paying small amounts, up to SFr 200, in a test and an attempt to advance Zug as a region that is advancing future technologies. In order to reduce risk, Zug immediately converts any bitcoin received into the Swiss currency. Swiss Federal Railways, government-owned railway company of Switzerland, sells bitcoins at its ticket machines.
=== UK ===
In 2016, the UK's chief scientific adviser, Sir Mark Walport, advised the government to consider using a blockchain-based digital currency.The chief economist of Bank of England, the central bank of the United Kingdom, proposed the abolition of paper currency. The Bank has also taken an interest in blockchain. In 2016 it has embarked on a multi-year research programme to explore the implications of a central bank issued digital currency. The Bank of England has produced several research papers on the topic. One suggests that the economic benefits of issuing a digital currency on a distributed ledger could add as much as 3 percent to a country's economic output. The Bank said that it wanted the next version of the bank's basic software infrastructure to be compatible with distributed ledgers.
== Adoption by financial actors ==
Government attitude dictates the tendency among established heavy financial actors that both are risk-averse and conservative. None of these offered services around cryptocurrencies and much of the criticism came from them. "The first mover among these has been Fidelity Investments, Boston based Fidelity Digital Assets LLC will provide enterprise-grade custody solutions, a cryptocurrency trading execution platform and institutional advising services 24 hours a day, seven days a week designed to align with blockchain's always-on trading cycle". It will work with Bitcoin and Ethereum with general availability scheduled for 2019.
== Hard vs. soft digital currencies ==
Hard electronic currency does not have the ability to be disputed or reversed when used. It is nearly impossible to reverse a transaction, justified or not. It is very similar to cash. Contrarily, soft electronic currency payments can be reversed. Usually, when a payment is reversed there is a "clearing time." A hard currency can be "softened" with a third-party service.
== Criticism ==
Many existing digital currencies have not yet seen widespread usage, and may not be easily used or exchanged. Banks generally do not accept or offer services for them. There are concerns that cryptocurrencies are extremely risky due to their very high volatility and potential for pump and dump schemes. Regulators in several countries have warned against their use and some have taken concrete regulatory measures to dissuade users. The non-cryptocurrencies are all centralized. As such, they may be shut down or seized by a government at any time. The more anonymous a currency is, the more attractive it is to criminals, regardless of the intentions of its creators. Bitcoin has also been criticised for its energy inefficient SHA-256-based proof of work.According to Barry Eichengreen, an economist known for his work on monetary and financial economics, "cryptocurrencies like Bitcoin are too volatile to possess the essential attributes of money. Stablecoins have fragile currency pegs that diminish their utility in transactions. And central bank digital currencies are a solution in search of a problem."
== List ==
=== Non-cryptocurrencies ===
== See also ==
Complementary currency
Automated clearing house
Cashless catering
Cashless society
Community Exchange System
Cryptocurrency exchange
Cryptocurrency wallet
Central bank digital currency
Digital wallet
E-commerce payment system
Electronic Money Association
Electronic funds transfer
Local exchange trading system
Payment system
Private currency
Privacy
== References == |
Central bank digital currency | A central bank digital currency (CBDC; also called digital fiat currency or digital base money) is a digital currency issued by a central bank, rather than by a commercial bank. It is also a liability of the central bank and denominated in the sovereign currency, as is the case with physical banknotes and coins.
There are two general models that CBDCs most commonly described as falling under: retail and wholesale. Retail CBDCs are designed for households and businesses to make payments for everyday transactions, while wholesale CBDCs are designed for financial institutions and operate similarly to central bank reserves. Other CBDC models have emerged as well over time. Most notably, the Federal Reserve proposed an intermediated CBDC in 2022. In this model, the central bank issues a sort of retail CBDC, but financial intermediaries offer customer services.
The present concept of CBDCs differs from virtual currency and cryptocurrency in that a CBDC is or would be issued by a state. Most CBDC implementations will likely not use or need any sort of distributed ledger such as a blockchain.In 2023, over 120 different jurisdictions, including major economies like the ECB, UK, and the US, were evaluating national digital currencies. As it currently stands, 9 countries and the 8 islands making up the Eastern Caribbean Currency Union have launched CBDCs; 38 countries and Hong Kong have CBDC pilot programs; and 67 countries and 2 currency unions are researching CBDCs.CBDCs have faced a plethora of criticisms among those being that a "centrally managed, centrally controlled, CBDC is a tool for coercion and control" and that it would "allow the government to spy on" the citizenry.
== History ==
Although the term "CBDC" did not become widely used until after 2019, central banks have researched and launched digital currency projects for decades. For example, Finland's central bank issued the Avant stored value e-money card in the 1990s. In 2014, the Chinese central bank began researching the idea of issuing a CBDC. Elsewhere, the Ecuadorian central bank operated a mobile payment system from 2014 to 2018.
== Implementation ==
A central bank digital currency would likely be implemented using a database run by the central bank, government, or approved private-sector entities. The database would keep a record (with appropriate privacy and cryptographic protections) of the amount of money held by every entity, such as people and corporations.In contrast to cryptocurrency, a central bank digital currency would be centrally controlled (even if it was on a distributed database), and so a blockchain or other distributed ledger would likely not be required or useful - even as they were the original inspiration for the concept.In 2023, the central banks of 114 countries accounting for 95% of the world’s GDP were said to be in various stages of evaluating the launch of a national digital currency. These included the ECB, the UK, and the US. China's digital RMB was the first digital currency to be issued by a major economy. Six central banks have launched a CBDC: the Central Bank of The Bahamas (Sand Dollar), the Eastern Caribbean Central Bank (DCash), the Central Bank of Nigeria (e-Naira), the Bank of Jamaica (JamDex), People's Bank of China (Digital renminbi), the Reserve Bank of India (Digital Rupee), and Bank of Russia (Digital Ruble). The Central Bank of Brazil has been rolling out tests of a digital Brazilian currency (Drex) since March 2023. The ECB/Eurozone decided in October 2023 to move forward to the preparation phase for the potential issuance of a digital euro after a two-year study phase.Some states have also issued, or have considered issuing, cryptocurrencies: these include Venezuela (Petro) and the Marshall Islands (Sovereign). These cryptocurrencies are often considered with the intent of increasing a state's independence from global financial systems, such as by reducing dependence on a foreign currency or by evading international sanctions.Contrasting attitudes towards digital currencies were demonstrated by developments in the UK and Switzerland in February 2023. The UK Treasury and the Bank of England said a state-backed digital pound was likely to be launched some time after 2025. Two weeks later, a Swiss lobby group triggered a national vote on maintaining a "sufficient quantity" of cash in circulation over fears that electronic payments make it easier for the state to monitor its citizens' actions. In a comment on the British government’s plans, the BBC's Faisal Islam said the issue was about access to the data attached to every spending transaction, and whether people might choose to trust a global company more than the state: "The eye here is on maintaining UK monetary sovereignty against upheaval from the likes of Big Tech."A major problem with central bank digital currencies is deciding whether the currency should be easily trackable. If it's traceable, the government has more control than it currently does. Additionally, there's a technical aspect to consider: whether CBDCs should be based on tokens or accounts and how much anonymity users should have.
== Characteristics ==
A CBDC is a high-security digital instrument; like paper banknotes, it is a means of payment, a unit of account, and a store of value. And like paper currency, each unit is uniquely identifiable to prevent counterfeiting. CBDC will have implications for commercial banks, probably in the field of lowering banks' commissions, no big customer data-selling ability, accumulating the deposits and deposit policies and credit policies due to higher funding costs for banks.Digital fiat currency is part of the base money supply, together with other forms of the currency. As such, DFC is a liability of the central bank just as physical currency is. It is a digital bearer instrument that can be stored, transferred and transmitted by all kinds of digital payment systems and services. The validity of the digital fiat currency is independent of the digital payment systems storing and transferring the digital fiat currency.Proposals for CBDC implementation often involve the provision of universal bank accounts at the central banks for all citizens.
== Benefits and impacts ==
Governments and central banks are studying CBDCs and their implications for financial inclusion, economic growth, technology innovation, and the efficiency of bank transactions. Potential advantages include:
Technological efficiency: instead of relying on intermediaries such as banks and clearing houses, money transfers and payments could be made in real time, directly from the payer to the payee. Being real time has some advantages:
Reduces risk: payment for goods and services often needs to be done in a timely manner and when payment verification is slow, merchants usually accept the risk of some payments not succeeding in exchange for faster service to customers. When these risks are eliminated with instant payment verifications, merchants no longer need to use intermediaries to handle the risk or to absorb the risk cost themselves.
Reduces complexity: merchants will not need to separately keep track of transactions that are slow (where the customer claims to have paid but the money has not arrived yet), therefore eliminate the waiting queue, which could simplify the transaction process from payment to rendition of goods/services.
Reduces (or eliminates) transaction fees: current payment systems like Visa, Mastercard, American Express etc. have a fee attached to each transaction and lowering or eliminating these fees could lead to widespread price drops and increased adoption of digital payments.
Financial inclusion: safe money accounts at the central banks could constitute a strong instrument of financial inclusion, allowing any legal resident or citizen to be provided with a free or low-cost basic bank account.
Preventing illicit activity: A CBDC makes it feasible for a central bank to keep track of the exact location of every unit of the currency (assuming the more probable centralized, database form)Tax collection: It makes tax avoidance and tax evasion much more difficult, since it would become impossible to use methods such as offshore banking and unreported employment to hide financial activity from the central bank or government. However, cryptos like Bitcoin risk undermining effort to crack down on corporate tax avoidance.
Combating crime: It makes it much easier to spot criminal activity (by observing financial activity), and thus put an end to it. Furthermore, in cases where criminal activity has already occurred, tracking makes it much harder to successfully launder money, and it would often be straightforward to instantly reverse a transaction and return money to the victim of the crime.
Proof of transaction: a digital record exists to prove that money changed hands between two parties which avoids problems inherent to cash such as short-changing, cash theft and conflicting testimonies.
Protection of money as a public utility: digital currencies issued by central banks would provide a modern alternative to physical cash – whose abolition is currently being envisaged.
Safety of payments systems: A secure and standard interoperable digital payment instrument issued and governed by a Central Bank and used as the national digital payment instruments boosts confidence in privately controlled money systems and increases trust in the entire national payment system while also boosting competition in payment systems.
Preservation of seigniorage income: public digital currency issuance would avoid a predictable reduction of seigniorage income for governments in the event of a disappearance of physical cash.
Banking competition: the provision of free bank accounts at the central bank offering complete safety of money deposits could strengthen competition between banks to attract bank deposits, for example by offering once again remunerated sight deposits.
Monetary policy transmission: the issuance of central bank base money through transfers to the public could constitute a new channel for monetary policy transmission (i.e. helicopter money), which would allow more direct control of the money supply than indirect tools such as quantitative easing and interest rates, and possibly lead the way towards a full reserve banking system. In digital Yuan trial in Shenzhen, the CBDC was programmed with an expiration date, which encouraged spending and discouraged money from sitting in a saving account. In the end, 90% of vouchers were spent in shops. Demurrage could be implemented, such as by shaving off fractions of the value on a scheduled basis, as a supplement to traditional inflation targets.
Financial safety: CBDC would provide an alternative to fractional reserve banking for daily uses, for those who want to avoid all risk of bank runs, despite the relative safety provided by deposit insurance.
== Risks ==
Despite having potential advantages, CBDCs remain a controversial topic, and there are risks associated with their implementation.
Banking system disintermediation: With the ability to provide digital currency directly to its citizens, one concern is that depositors would shift out of the banking system. Customers may deem the safety, liquidity, solvibility, and publicity of CBDCs to be more attractive, weakening the balance sheet position of commercial banks. In the extreme, this could precipitate potential bank runs and thus make banks' funding positions weaker. However, the Bank of England found that if the introduction of CBDC follows a set of core principles, the risk of a system-wide run from bank deposits to CBDC is addressed. A central bank could also limit the demand of CBDCs by setting a ceiling on the amount of holdings.Centralization: Since most central bank digital currencies are centralized, rather than decentralized like most cryptocurrencies, the controllers of the issuance of CBDCs can add or remove money from anyone's account with a flip of a switch. In contrast, cryptocurrencies with a distributed ledger such as Bitcoin prevent this unless a group of users controlling more than 50% of mining power is in agreement.
Digital dollarization: A well-run foreign digital currency could become a replacement for a local currency for the same reasons as those described in dollarization. The announcement of Facebook's Libra contributed to the increased attention to CBDCs by central bankers, as well as China's progress with DCEP to that of several Asian economies.
Privacy:
"Governments have direct visibility of financial transactions", an "eagle-eyed view on the spending of everyone".
Digital currency would give a country "broad new powers when it comes to surveillance and controlling its population."
Data from tracing money routes could lead to losing financial privacy if the CBDC implementation does not have adequate privacy protections. This could lead to encouraging of self-censorship, deterioration of freedom of expression and association, and ultimately to stalling social developments.
Government Social Manipulation:
Digital currency "will simply become an extension of the surveillance state" and "it could see citizens fined in a split second for behaviors deemed undesirable. Dissidents and activists could see their wallets emptied or taken offline."
Limiting individual freedom: "Digital currencies could also empower the state to make it impossible to donate to a vocal NGO"
Limiting or prohibiting purchases of products: Digital currency could prohibit a "purchase alcohol on a weekday. "
Digital currency " is also programmable. The government could theoretically give out money that expires within a certain period of time or money that could only be used on certain items, which could be used to induce behaviour that the government is seeking."
Direct interaction with individuals: "In times of crisis, they enable governments to send aid and stimulus payments directly to the smartphones of affected citizens, regardless of whether the recipients have a bank account or not."
Forcing consumer behavior: "Digital currencies can also be tailored to specific purposes. For example, in the Chinese pilot program, money has an expiration date of a few weeks because authorities are hoping to drive consumption"
== See also ==
ENaira
Digital renminbi
Digital rupee
Digital currency
mBridge
M-Pesa
E-Cedi
History of CBDCs by country
Central bank
== References ==
== External links ==
Atlantic Council CBDC Tracker |
Litecoin | Litecoin (Abbreviation: LTC; sign: Ł) is a decentralized peer-to-peer cryptocurrency and open-source software project released under the MIT/X11 license. Inspired by Bitcoin, Litecoin was among the earliest altcoins, starting in October 2011. In technical details, the Litecoin main chain shares a slightly modified Bitcoin codebase. The practical effects of those codebase differences are lower transaction fees, faster transaction confirmations, and faster mining difficulty retargeting. Due to its underlying similarities to Bitcoin, Litecoin has historically been referred to as the "silver to Bitcoin's gold." In 2022, Litecoin added optional privacy features via soft fork through the MWEB (MimbleWimble extension block) upgrade.
== Design ==
=== Units and divisibility ===
Currency codes for representing litecoin is LTC. Its Unicode character is Ł.
One litecoin is divisible to eight decimal places. Units for smaller amounts of litecoin are:
lites, or millilitecoin (mŁ), equal to 1⁄1000 litecoin,
photons, or microlitecoin (μŁ), equal to 1⁄1000000,
the litoshi, which is the smallest possible division, and named in homage to bitcoin's smallest denomination the satoshi, representing 1⁄100000000 (one hundred millionth) litecoin.
== History ==
=== Pre-Litecoin ===
By 2011, Bitcoin mining was largely performed by GPUs. This raised concern in some users that mining now had a high barrier to entry, and that CPU resources were becoming obsolete and worthless for mining. Using code from Bitcoin, a new alternative currency was created called Tenebrix (TBX). Tenebrix replaced the SHA-256 rounds in Bitcoin's mining algorithm with the scrypt function, which had been specifically designed in 2009 to be expensive to accelerate with FPGA or ASIC chips. This would allow Tenebrix to have been "GPU-resistant", and utilize the available CPU resources from bitcoin miners. Tenebrix itself was a successor project to an earlier cryptocurrency which replaced Bitcoin's issuance schedule with a constant block reward (thus creating an unlimited money supply). However, the developers included a clause in the code that would allow them to claim 7.7 million TBX for themselves at no cost, which was criticized by users.To address this, Charlie Lee, a Google employee who would later become engineering director at Coinbase, created an alternative version of Tenebrix called Fairbrix (FBX). Litecoin inherits the scrypt mining algorithm from Fairbrix, but returns to the limited money supply of Bitcoin, with other changes.
=== Creation and launch ===
Lee released Litecoin via an open-source client on GitHub on October 7, 2011. The Litecoin network went live on October 13, 2011.
Litecoin was a source code fork of the Bitcoin Core client, originally differing by having a decreased block generation time (2.5 minutes), increased maximum number of coins, different hashing algorithm (scrypt, instead of SHA-256), faster difficulty retarget, and a slightly modified GUI.
=== 2011–2016 ===
After launch, the early growth of Litecoin was aided by its increasing exchange availability and liquidity on early exchanges such as BTC-e. During the month of November 2013, the aggregate value of Litecoin experienced massive growth which included a 100% leap within 24 hours.In early 2014, Lee suggested merge mining (auxPOW) Dogecoin with Litecoin to the Dogecoin community at large. In September 2014, Dogecoin began merge-mining with Litecoin, providing increased security for Dogecoin and a permanent block subsidy that previously was not available with Litecoin mining.
=== 2017–2021 ===
In 2020, PayPal added the ability for users to purchase a derivative of Litecoin along with Bitcoin, Ethereum and Bitcoin Cash which could not be withdrawn or spent as part of its Crypto feature.
In September 2021, a fake press release was published on GlobeNewswire announcing a partnership between Litecoin and Walmart. This caused the price of Litecoin to increase by around 30%, before the press release was revealed as a hoax.
=== 2022–present ===
In May 2022, MWEB (Mimblewimble Extension Blocks) upgrade was activated on the Litecoin network as a soft fork. This upgrade provides users with the option of sending confidential Litecoin transactions, in which the amount being sent is only known between the sender and receiver.In June 2022, PayPal added the ability for users to transfer Litecoin along with Bitcoin, Ethereum and Bitcoin Cash between PayPal to other wallets and exchanges.
== Differences from Bitcoin ==
Litecoin is different in some ways from Bitcoin:
The targeted block time is every 2.5 minutes for Litecoin, as opposed to Bitcoin's 10 minutes. This allows Litecoin to confirm transactions four times faster than Bitcoin.
Scrypt, an alternative proof-of-work algorithm, is used for Litecoin. It differs from Bitcoin's SHA-256 algorithm in part by including a sequential memory-hard function, requiring asymptotically more memory than an algorithm which is not memory-hard. Due to Litecoin's use of the scrypt algorithm, FPGA and ASIC devices made for mining Litecoin are more complicated to create and more expensive to produce than they are for Bitcoin, which uses SHA-256.
Litecoin is merge mined with another prominent cryptocurrency (Dogecoin), increasing miner compensation and network security for both blockchains.
Litecoin has a maximum circulating supply of Ł84,000,000, which is four times larger than Bitcoin's maximum circulating supply of ₿21,000,000.
Both Litecoin and Bitcoin retarget their mining difficulty every 2016 blocks. However, due to the 4x faster block speed for Litecoin, mining difficulty retargets occur approximately every 3.5 days. This compares to approximately every 14 days for Bitcoin.
MWEB optional privacy was added to Litecoin's base layer in May 2022 via soft fork. This allows amounts held within wallets and transaction amounts within MWEB to be private.Third party vendors providing point of sale infrastructure for Litecoin include companies such as Verifone, BitPay, and Coingate. BitPay added support for Litecoin in 2021, with Litecoin initially accounting for less than 3% of BitPay transactions. As of June 2023, Litecoin surpassed Bitcoin as the #1 most used method for transactions by payment count with 34.9%.
== See also ==
List of scrypt crypto currencies
== Notes ==
== References ==
== External links ==
Litecoin Foundation |
Satoshi Nakamoto | Satoshi Nakamoto is the name used by the presumed pseudonymous person or persons who developed Bitcoin, authored the bitcoin white paper, and created and deployed bitcoin's original reference implementation. As part of the implementation, Nakamoto also devised the first blockchain database. Nakamoto was active in the development of bitcoin up until December 2010.There has been widespread speculation about Satoshi Nakamoto's true identity, with various people posited as the person or persons behind the name. Though Nakamoto's name is Japanese, and he stated in 2012 that he was a man living in Japan, most of the speculation has involved software and cryptography experts in the United States or Europe.
== Development of bitcoin ==
Nakamoto stated that work on the writing of the code for Bitcoin began in the spring of 2007. On 18 August 2008, he or a colleague registered the domain name bitcoin.org, and created a web site at that address. On 31 October, Nakamoto published a white paper on the cryptography mailing list at metzdowd.com describing a digital cryptocurrency, titled "Bitcoin: A Peer-to-Peer Electronic Cash System".On 9 January 2009, Nakamoto released version 0.1 of the Bitcoin software on SourceForge and launched the network by defining the genesis block of bitcoin (block number 0), which had a reward of 50 bitcoins. Embedded in the coinbase transaction of this block is the text: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks", citing a headline in the UK newspaper The Times published on that date. This note has been interpreted as both a timestamp and a derisive comment on the alleged instability caused by fractional-reserve banking.: 18 Nakamoto continued to collaborate with other developers on the Bitcoin software until mid-2010, making all modifications to the source code himself. He then gave control of the source code repository and network alert key to Gavin Andresen, transferred several related domains to various prominent members of the bitcoin community, and stopped his recognized involvement in the project.Nakamoto owns between 750,000 and 1,100,000 bitcoin. In November 2021, when Bitcoin hit its still-highest value of over US$68,000, that would have made his net worth up to US$73 billion, making him the 15th-richest person in the world at the time.
== Characteristics and identity ==
Nakamoto has never revealed personal information when discussing technical matters, though has at times provided commentary on banking and fractional-reserve banking. On his P2P Foundation profile as of 2012, Nakamoto claimed to be a 37-year-old male who lived in Japan; however, some speculated he was unlikely to be Japanese due to his native-level use of English.Some have considered that Nakamoto might be a team of people. Dan Kaminsky, a security researcher who read the bitcoin code, said that Nakamoto could either be a "team of people" or a "genius"; Laszlo Hanyecz, a developer who had emailed Nakamoto, had the feeling the code was too well designed for one person; Gavin Andresen has said of Nakamoto's code: "He was a brilliant coder, but it was quirky."The use of British English in both source code comments and forum postings, such as the expression "bloody hard", terms such as "flat" and "maths", and the spellings "grey" and "colour", led to speculation that Nakamoto, or at least one individual in a consortium claiming to be him, was of Commonwealth origin. The reference to London's Times newspaper in the first bitcoin block mined by Nakamoto suggested to some a particular interest in the British government.Stefan Thomas, a Swiss software engineer and active community member, graphed the timestamps for each of Nakamoto's bitcoin forum posts (more than 500); the chart showed a steep decline to almost no posts between the hours of 5 a.m. and 11 a.m. Greenwich Mean Time (or midnight to 6 a.m. Eastern Standard Time). This was between 2 p.m. and 8 p.m. Japan Standard Time, suggesting an unusual sleep pattern for someone supposedly living in Japan. As this pattern held even on Saturdays and Sundays, it suggested that Nakamoto was consistently asleep at this time.
=== Possible identities ===
The identity of Nakamoto is unknown, but speculations have focussed on various cryptography and computer science experts, most of non-Japanese descent.
==== Hal Finney ====
Hal Finney (4 May 1956 – 28 August 2014) was a pre-bitcoin cryptographic pioneer and the first person (other than Nakamoto himself) to use the software, file bug reports, and make improvements. He also lived a few blocks from a man named 'Dorian Satoshi Nakamoto', according to Forbes journalist Andy Greenberg. Greenberg asked the writing analysis consultancy Juola & Associates to compare a sample of Finney's writing to Nakamoto's, and found it to be the closest resemblance they had yet come across, including when compared to candidates suggested by Newsweek, Fast Company, The New Yorker, Ted Nelson, and Skye Grey. Greenberg theorized that Finney may have been a ghostwriter on behalf of Nakamoto, or that he simply used his neighbor Dorian's identity as a "drop" or "patsy whose personal information is used to hide online exploits"; however, after meeting Finney, seeing the emails between him and Nakamoto and his bitcoin wallet's history (including the very first bitcoin transaction from Nakamoto to him, which he forgot to pay back) and hearing his denial, Greenberg concluded that Finney was telling the truth. Juola & Associates also found that Nakamoto's emails to Finney more closely resemble Nakamoto's other writings than Finney's do. Finney's fellow extropian and sometimes co-blogger Robin Hanson assigned a subjective probability of "at least" 15% that "Hal was more involved than he's said", before further evidence suggested that was not the case.
==== Dorian Nakamoto ====
In a high-profile 6 March 2014 article in the magazine Newsweek, journalist Leah McGrath Goodman identified Dorian Prentice Satoshi Nakamoto, a Japanese American man living in California, whose birth name is Satoshi Nakamoto, as the Nakamoto in question. Besides his name, Goodman pointed to a number of facts that circumstantially suggested he was the Bitcoin inventor. Trained as a physicist at California State Polytechnic University, Pomona, Nakamoto worked as a systems engineer on classified defense projects and computer engineer for technology and financial information services companies. Nakamoto was laid off twice in the early 1990s and turned libertarian according to his daughter and encouraged her to start her own business "not under the government's thumb." In the article's seemingly biggest piece of evidence, Goodman wrote that when she asked him about Bitcoin during a brief in-person interview, Nakamoto seemed to confirm his identity as the Bitcoin founder by stating: "I am no longer involved in that and I cannot discuss it. It's been turned over to other people. They are in charge of it now. I no longer have any connection."The article's publication led to a flurry of media interest, including reporters camping out near Dorian Nakamoto's house and subsequently chasing him by car when he drove to do an interview. Later that day, the pseudonymous Nakamoto's P2P Foundation account posted its first message in five years, stating: "I am not Dorian Nakamoto." During the subsequent full-length interview, Dorian Nakamoto denied all connection to Bitcoin, saying he had never heard of the currency before, and that he had misinterpreted Goodman's question as being about his previous work for military contractors, much of which was classified. In a Reddit "ask-me-anything" interview, he claimed he had misinterpreted Goodman's question as being related to his work for Citibank. In September, the P2P Foundation account posted another message saying it had been hacked, raising questions over the authenticity of the message six months earlier.
==== Nick Szabo ====
In December 2013, blogger Skye Grey linked Nick Szabo to the Bitcoin white paper using an approach he described as stylometric analysis. Szabo is a decentralized currency enthusiast and had published a paper on "bit gold", one of the precursors of Bitcoin. He is known to have been interested in using pseudonyms in the 1990s. In a May 2011 article, Szabo stated about the Bitcoin creator: "Myself, Wei Dai, and Hal Finney were the only people I know of who liked the idea (or in Dai's case his related idea) enough to pursue it to any significant extent until Nakamoto (assuming Nakamoto is not really Finney or Dai)."Financial author Dominic Frisby provides much circumstantial evidence but, as he admits, no proof that Nakamoto is Szabo. Szabo has denied being Nakamoto. In a July 2014 email to Frisby, he said: "Thanks for letting me know. I'm afraid you got it wrong doxing me as Satoshi, but I'm used to it." Nathaniel Popper wrote in The New York Times that "the most convincing evidence pointed to a reclusive American man of Hungarian descent named Nick Szabo."
==== Craig Wright ====
On 8 December 2015, Wired wrote that Craig Steven Wright, an Australian academic, "either invented bitcoin or is a brilliant hoaxer who very badly wants us to believe he did". Craig Wright took down his Twitter account and neither he nor his ex-wife responded to press inquiries. The same day, Gizmodo published a story with evidence supposedly obtained by a hacker who broke into Wright's email accounts, claiming that Satoshi Nakamoto was a joint pseudonym for Craig Steven Wright and computer forensics analyst David Kleiman, who died in 2013. Wright's claim was supported by Jon Matonis (former director of the Bitcoin Foundation) and bitcoin developer Gavin Andresen.Wright has stated that he chose the family name "Nakamoto" in honor of Japanese philosopher Tominaga Nakamoto (1715–1746), whom Wright learned about from his Japanese martial arts instructor, and the accompanying given name "Satoshi" after the Pokémon character Satoshi, because his name was anglicized as "Ash", and thus "Satoshi" represents the current financial system that must be burned into ash in order to make way for cryptocurrency.A number of prominent Bitcoin promoters remained unconvinced by the reports. Subsequent reports also raised the possibility that the evidence provided was an elaborate hoax, which Wired acknowledged "cast doubt" on their suggestion that Wright was Nakamoto. Bitcoin developer Peter Todd said that Wright's blog post, which appeared to contain cryptographic proof, actually contained nothing of the sort. Bitcoin developer Jeff Garzik agreed that evidence publicly provided by Wright does not prove anything, and security researcher Dan Kaminsky concluded Wright's claim was "intentional scammery".In May 2019, Wright started using English libel law to sue people who denied he was the inventor of bitcoin, and who called him a fraud. In 2019, Wright registered US copyright for the bitcoin white paper and the code for Bitcoin 0.1. Wright's team claimed this was "government agency recognition of Craig Wright as Satoshi Nakamoto"; the United States Copyright Office issued a press release clarifying that this was not the case (as they primarily determine whether a work is eligible for copyright, and do not investigate legal ownership, which, if disputed, is determined by the courts).
==== Other candidates ====
In a 2011 article in The New Yorker, Joshua Davis claimed to have narrowed down the identity of Nakamoto to a number of possible individuals, including the Finnish economic sociologist Dr. Vili Lehdonvirta and Irish student Michael Clear, who was in 2008 an undergraduate student in cryptography at Trinity College Dublin. Clear strongly denied he was Nakamoto, and so did Lehdonvirta.In October 2011, writing for Fast Company, investigative journalist Adam Penenberg cited circumstantial evidence suggesting Neal King, Vladimir Oksman and Charles Bry could be Nakamoto. They jointly filed a patent application that contained the phrase "computationally impractical to reverse" in 2008, which was also used in the Bitcoin white paper by Nakamoto. The domain name bitcoin.org was registered three days after the patent was filed. All three men denied being Nakamoto when contacted by Penenberg.In May 2013, Ted Nelson speculated that Nakamoto was Japanese mathematician Shinichi Mochizuki. Later, an article was published in The Age newspaper that claimed that Mochizuki denied these speculations, but without attributing a source for the denial.A 2013 article in Vice listed Gavin Andresen, Jed McCaleb, or a government agency as possible candidates to be Nakamoto.In 2013, two Israeli mathematicians, Dorit Ron and Adi Shamir, published a paper claiming a link between Nakamoto and Ross Ulbricht. The two based their suspicion on an analysis of the network of Bitcoin transactions, but later retracted their claim.In 2016, the Financial Times said that Nakamoto might have been a group of people, mentioning Hal Finney, Nick Szabo and Adam Back as potential members. In 2020, the YouTube channel Barely Sociable claimed that Adam Back, inventor of Bitcoin predecessor Hashcash, is Nakamoto. Back subsequently denied this. Charles Hoskinson, founder of Cardano and co-founder of Ethereum, has also opined that Adam Back is the most likely candidate for Nakamoto.Elon Musk denied he was Nakamoto in a tweet on 28 November 2017, responding to speculation the previous week in a Medium post by a former SpaceX intern.In 2019, journalist Evan Ratliff claimed drug dealer Paul Le Roux could be Nakamoto.In 2021, developer Evan Hatch proposed cypherpunk Len Sassaman of COSIC as a possible candidate. Sassaman had been mentioned on bitcointalk on 15 March 2013 when a user suggested Sassaman was Satoshi.
== In popular culture ==
A bust of Satoshi Nakamoto was installed in Hungary in 2021.
== References == |
Blockchain | A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked together via cryptographic hashes. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). Since each block contains information about the previous block, they effectively form a chain (compare linked list data structure), with each additional block linking to the ones before it. Consequently, blockchain transactions are irreversible in that, once they are recorded, the data in any given block cannot be altered retroactively without altering all subsequent blocks.
Blockchains are typically managed by a peer-to-peer (P2P) computer network for use as a public distributed ledger, where nodes collectively adhere to a consensus algorithm protocol to add and validate new transaction blocks. Although blockchain records are not unalterable, since blockchain forks are possible, blockchains may be considered secure by design and exemplify a distributed computing system with high Byzantine fault tolerance.A blockchain was created by a person (or group of people) using the name (or pseudonym) Satoshi Nakamoto in 2008 to serve as the public distributed ledger for bitcoin cryptocurrency transactions, based on previous work by Stuart Haber, W. Scott Stornetta, and Dave Bayer. The implementation of the blockchain within bitcoin made it the first digital currency to solve the double-spending problem without the need for a trusted authority or central server. The bitcoin design has inspired other applications and blockchains that are readable by the public and are widely used by cryptocurrencies. The blockchain may be considered a type of payment rail.Private blockchains have been proposed for business use. Computerworld called the marketing of such privatized blockchains without a proper security model "snake oil"; however, others have argued that permissioned blockchains, if carefully designed, may be more decentralized and therefore more secure in practice than permissionless ones.
== History ==
Cryptographer David Chaum first proposed a blockchain-like protocol in his 1982 dissertation "Computer Systems Established, Maintained, and Trusted by Mutually Suspicious Groups." Further work on a cryptographically secured chain of blocks was described in 1991 by Stuart Haber and W. Scott Stornetta. They wanted to implement a system wherein document timestamps could not be tampered with. In 1992, Haber, Stornetta, and Dave Bayer incorporated Merkle trees into the design, which improved its efficiency by allowing several document certificates to be collected into one block. Under their company Surety, their document certificate hashes have been published in The New York Times every week since 1995.The first decentralized blockchain was conceptualized by a person (or group of people) known as Satoshi Nakamoto in 2008. Nakamoto improved the design in an important way using a Hashcash-like method to timestamp blocks without requiring them to be signed by a trusted party and introducing a difficulty parameter to stabilize the rate at which blocks are added to the chain. The design was implemented the following year by Nakamoto as a core component of the cryptocurrency bitcoin, where it serves as the public ledger for all transactions on the network.In August 2014, the bitcoin blockchain file size, containing records of all transactions that have occurred on the network, reached 20 GB (gigabytes). In January 2015, the size had grown to almost 30 GB, and from January 2016 to January 2017, the bitcoin blockchain grew from 50 GB to 100 GB in size. The ledger size had exceeded 200 GB by early 2020.The words block and chain were used separately in Satoshi Nakamoto's original paper, but were eventually popularized as a single word, blockchain, by 2016.According to Accenture, an application of the diffusion of innovations theory suggests that blockchains attained a 13.5% adoption rate within financial services in 2016, therefore reaching the early adopters' phase. Industry trade groups joined to create the Global Blockchain Forum in 2016, an initiative of the Chamber of Digital Commerce.
In May 2018, Gartner found that only 1% of CIOs indicated any kind of blockchain adoption within their organisations, and only 8% of CIOs were in the short-term "planning or [looking at] active experimentation with blockchain". For the year 2019 Gartner reported 5% of CIOs believed blockchain technology was a 'game-changer' for their business.
== Structure and design ==
A blockchain is a decentralized, distributed, and often public, digital ledger consisting of records called blocks that are used to record transactions across many computers so that any involved block cannot be altered retroactively, without the alteration of all subsequent blocks. This allows the participants to verify and audit transactions independently and relatively inexpensively. A blockchain database is managed autonomously using a peer-to-peer network and a distributed timestamping server. They are authenticated by mass collaboration powered by collective self-interests. Such a design facilitates robust workflow where participants' uncertainty regarding data security is marginal. The use of a blockchain removes the characteristic of infinite reproducibility from a digital asset. It confirms that each unit of value was transferred only once, solving the long-standing problem of double-spending. A blockchain has been described as a value-exchange protocol. A blockchain can maintain title rights because, when properly set up to detail the exchange agreement, it provides a record that compels offer and acceptance.Logically, a blockchain can be seen as consisting of several layers:
infrastructure (hardware)
networking (node discovery, information propagation and verification)
consensus (proof of work, proof of stake)
data (blocks, transactions)
application (smart contracts/decentralized applications, if applicable)
=== Blocks ===
Blocks hold batches of valid transactions that are hashed and encoded into a Merkle tree. Each block includes the cryptographic hash of the prior block in the blockchain, linking the two. The linked blocks form a chain. This iterative process confirms the integrity of the previous block, all the way back to the initial block, which is known as the genesis block (Block 0). To assure the integrity of a block and the data contained in it, the block is usually digitally signed.Sometimes separate blocks can be produced concurrently, creating a temporary fork. In addition to a secure hash-based history, any blockchain has a specified algorithm for scoring different versions of the history so that one with a higher score can be selected over others. Blocks not selected for inclusion in the chain are called orphan blocks. Peers supporting the database have different versions of the history from time to time. They keep only the highest-scoring version of the database known to them. Whenever a peer receives a higher-scoring version (usually the old version with a single new block added) they extend or overwrite their own database and retransmit the improvement to their peers. There is never an absolute guarantee that any particular entry will remain in the best version of history forever. Blockchains are typically built to add the score of new blocks onto old blocks and are given incentives to extend with new blocks rather than overwrite old blocks. Therefore, the probability of an entry becoming superseded decreases exponentially as more blocks are built on top of it, eventually becoming very low.: ch. 08 For example, bitcoin uses a proof-of-work system, where the chain with the most cumulative proof-of-work is considered the valid one by the network. There are a number of methods that can be used to demonstrate a sufficient level of computation. Within a blockchain the computation is carried out redundantly rather than in the traditional segregated and parallel manner.
==== Block time ====
The block time is the average time it takes for the network to generate one extra block in the blockchain. By the time of block completion, the included data becomes verifiable. In cryptocurrency, this is practically when the transaction takes place, so a shorter block time means faster transactions. The block time for Ethereum is set to between 14 and 15 seconds, while for bitcoin it is on average 10 minutes.
==== Hard forks ====
=== Decentralization ===
By storing data across its peer-to-peer network, the blockchain eliminates some risks that come with data being held centrally. The decentralized blockchain may use ad hoc message passing and distributed networking.In a so-called "51% attack" a central entity gains control of more than half of a network and can then manipulate that specific blockchain record at will, allowing double-spending.Blockchain security methods include the use of public-key cryptography.: 5 A public key (a long, random-looking string of numbers) is an address on the blockchain. Value tokens sent across the network are recorded as belonging to that address. A private key is like a password that gives its owner access to their digital assets or the means to otherwise interact with the various capabilities that blockchains now support. Data stored on the blockchain is generally considered incorruptible.Every node in a decentralized system has a copy of the blockchain. Data quality is maintained by massive database replication and computational trust. No centralized "official" copy exists and no user is "trusted" more than any other. Transactions are broadcast to the network using the software. Messages are delivered on a best-effort basis. Early blockchains rely on energy-intensive mining nodes to validate transactions, add them to the block they are building, and then broadcast the completed block to other nodes.: ch. 08 Blockchains use various time-stamping schemes, such as proof-of-work, to serialize changes. Later consensus methods include proof of stake. The growth of a decentralized blockchain is accompanied by the risk of centralization because the computer resources required to process larger amounts of data become more expensive.
==== Finality ====
Finality is the level of confidence that the well-formed block recently appended to the blockchain will not be revoked in the future (is "finalized") and thus can be trusted. Most distributed blockchain protocols, whether proof of work or proof of stake, cannot guarantee the finality of a freshly committed block, and instead rely on "probabilistic finality": as the block goes deeper into a blockchain, it is less likely to be altered or reverted by a newly found consensus.Byzantine fault tolerance-based proof-of-stake protocols purport to provide so called "absolute finality": a randomly chosen validator proposes a block, the rest of validators vote on it, and, if a supermajority decision approves it, the block is irreversibly committed into the blockchain. A modification of this method, an "economic finality", is used in practical protocols, like the Casper protocol used in Ethereum: validators which sign two different blocks at the same position in the blockchain are subject to "slashing", where their leveraged stake is forfeited.
=== Openness ===
Open blockchains are more user-friendly than some traditional ownership records, which, while open to the public, still require physical access to view. Because all early blockchains were permissionless, controversy has arisen over the blockchain definition. An issue in this ongoing debate is whether a private system with verifiers tasked and authorized (permissioned) by a central authority should be considered a blockchain. Proponents of permissioned or private chains argue that the term "blockchain" may be applied to any data structure that batches data into time-stamped blocks. These blockchains serve as a distributed version of multiversion concurrency control (MVCC) in databases. Just as MVCC prevents two transactions from concurrently modifying a single object in a database, blockchains prevent two transactions from spending the same single output in a blockchain.: 30–31 Opponents say that permissioned systems resemble traditional corporate databases, not supporting decentralized data verification, and that such systems are not hardened against operator tampering and revision. Nikolai Hampton of Computerworld said that "many in-house blockchain solutions will be nothing more than cumbersome databases," and "without a clear security model, proprietary blockchains should be eyed with suspicion."
==== Permissionless (public) blockchain ====
An advantage to an open, permissionless, or public, blockchain network is that guarding against bad actors is not required and no access control is needed. This means that applications can be added to the network without the approval or trust of others, using the blockchain as a transport layer.Bitcoin and other cryptocurrencies currently secure their blockchain by requiring new entries to include proof of work. To prolong the blockchain, bitcoin uses Hashcash puzzles. While Hashcash was designed in 1997 by Adam Back, the original idea was first proposed by Cynthia Dwork and Moni Naor and Eli Ponyatovski in their 1992 paper "Pricing via Processing or Combatting Junk Mail".
In 2016, venture capital investment for blockchain-related projects was weakening in the USA but increasing in China. Bitcoin and many other cryptocurrencies use open (public) blockchains. As of April 2018, bitcoin has the highest market capitalization.
==== Permissioned (private) blockchain ====
Permissioned blockchains use an access control layer to govern who has access to the network. It has been argued that permissioned blockchains can guarantee a certain level of decentralization, if carefully designed, as opposed to permissionless blockchains, which are often centralized in practice.
===== Disadvantages of permissioned blockchain =====
Nikolai Hampton argued in Computerworld that "There is also no need for a '51 percent' attack on a private blockchain, as the private blockchain (most likely) already controls 100 percent of all block creation resources. If you could attack or damage the blockchain creation tools on a private corporate server, you could effectively control 100 percent of their network and alter transactions however you wished." This has a set of particularly profound adverse implications during a financial crisis or debt crisis like the financial crisis of 2007–08, where politically powerful actors may make decisions that favor some groups at the expense of others, and "the bitcoin blockchain is protected by the massive group mining effort. It's unlikely that any private blockchain will try to protect records using gigawatts of computing power — it's time-consuming and expensive." He also said, "Within a private blockchain there is also no 'race'; there's no incentive to use more power or discover blocks faster than competitors. This means that many in-house blockchain solutions will be nothing more than cumbersome databases."
==== Blockchain analysis ====
The analysis of public blockchains has become increasingly important with the popularity of bitcoin, Ethereum, litecoin and other cryptocurrencies. A blockchain, if it is public, provides anyone who wants access to observe and analyse the chain data, given one has the know-how. The process of understanding and accessing the flow of crypto has been an issue for many cryptocurrencies, crypto exchanges and banks. The reason for this is accusations of blockchain-enabled cryptocurrencies enabling illicit dark market trade of drugs, weapons, money laundering, etc. A common belief has been that cryptocurrency is private and untraceable, thus leading many actors to use it for illegal purposes. This is changing and now specialised tech companies provide blockchain tracking services, making crypto exchanges, law-enforcement and banks more aware of what is happening with crypto funds and fiat-crypto exchanges. The development, some argue, has led criminals to prioritise the use of new cryptos such as Monero.
=== Standardisation ===
In April 2016, Standards Australia submitted a proposal to the International Organization for Standardization to consider developing standards to support blockchain technology. This proposal resulted in the creation of ISO Technical Committee 307, Blockchain and Distributed Ledger Technologies. The technical committee has working groups relating to blockchain terminology, reference architecture, security and privacy, identity, smart contracts, governance and interoperability for blockchain and DLT, as well as standards specific to industry sectors and generic government requirements. More than 50 countries are participating in the standardization process together with external liaisons such as the Society for Worldwide Interbank Financial Telecommunication (SWIFT), the European Commission, the International Federation of Surveyors, the International Telecommunication Union (ITU) and the United Nations Economic Commission for Europe (UNECE).Many other national standards bodies and open standards bodies are also working on blockchain standards. These include the National Institute of Standards and Technology (NIST), the European Committee for Electrotechnical Standardization (CENELEC), the Institute of Electrical and Electronics Engineers (IEEE), the Organization for the Advancement of Structured Information Standards (OASIS), and some individual participants in the Internet Engineering Task Force (IETF).
=== Centralized blockchain ===
Although most of blockchain implementation are decentralized and distributed, Oracle launched a centralized blockchain table feature in Oracle 21c database. The Blockchain Table in Oracle 21c database is a centralized blockchain which provide immutable feature. Compared to decentralized blockchains, centralized blockchains normally can provide a higher throughput and lower latency of transactions than consensus-based distributed blockchains.
== Types ==
Currently, there are at least four types of blockchain networks — public blockchains, private blockchains, consortium blockchains and hybrid blockchains.
=== Public blockchains ===
A public blockchain has absolutely no access restrictions. Anyone with an Internet connection can send transactions to it as well as become a validator (i.e., participate in the execution of a consensus protocol). Usually, such networks offer economic incentives for those who secure them and utilize some type of a proof-of-stake or proof-of-work algorithm.
Some of the largest, most known public blockchains are the bitcoin blockchain and the Ethereum blockchain.
=== Private blockchains ===
A private blockchain is permissioned. One cannot join it unless invited by the network administrators. Participant and validator access is restricted. To distinguish between open blockchains and other peer-to-peer decentralized database applications that are not open ad-hoc compute clusters, the terminology Distributed Ledger (DLT) is normally used for private blockchains.
=== Hybrid blockchains ===
A hybrid blockchain has a combination of centralized and decentralized features. The exact workings of the chain can vary based on which portions of centralization and decentralization are used.
=== Sidechains ===
A sidechain is a designation for a blockchain ledger that runs in parallel to a primary blockchain. Entries from the primary blockchain (where said entries typically represent digital assets) can be linked to and from the sidechain; this allows the sidechain to otherwise operate independently of the primary blockchain (e.g., by using an alternate means of record keeping, alternate consensus algorithm, etc.).
=== Consortium blockchain ===
A consortium blockchain is a type of blockchain that combines elements of both public and private blockchains. In a consortium blockchain, a group of organizations come together to create and operate the blockchain, rather than a single entity. The consortium members jointly manage the blockchain network and are responsible for validating transactions. Consortium blockchains are permissioned, meaning that only certain individuals or organizations are allowed to participate in the network. This allows for greater control over who can access the blockchain and helps to ensure that sensitive information is kept confidential.
Consortium blockchains are commonly used in industries where multiple organizations need to collaborate on a common goal, such as supply chain management or financial services. One advantage of consortium blockchains is that they can be more efficient and scalable than public blockchains, as the number of nodes required to validate transactions is typically smaller. Additionally, consortium blockchains can provide greater security and reliability than private blockchains, as the consortium members work together to maintain the network. Some examples of consortium blockchains include Quorum and Hyperledger.
== Uses ==
Blockchain technology can be integrated into multiple areas. The primary use of blockchains is as a distributed ledger for cryptocurrencies such as bitcoin; there were also a few other operational products that had matured from proof of concept by late 2016. As of 2016, some businesses have been testing the technology and conducting low-level implementation to gauge blockchain's effects on organizational efficiency in their back office.In 2019, it was estimated that around $2.9 billion were invested in blockchain technology, which represents an 89% increase from the year prior. Additionally, the International Data Corp has estimated that corporate investment into blockchain technology will reach $12.4 billion by 2022. Furthermore, According to PricewaterhouseCoopers (PwC), the second-largest professional services network in the world, blockchain technology has the potential to generate an annual business value of more than $3 trillion by 2030. PwC's estimate is further augmented by a 2018 study that they have conducted, in which PwC surveyed 600 business executives and determined that 84% have at least some exposure to utilizing blockchain technology, which indicates a significant demand and interest in blockchain technology.In 2019, the BBC World Service radio and podcast series Fifty Things That Made the Modern Economy identified blockchain as a technology that would have far-reaching consequences for economics and society. The economist and Financial Times journalist and broadcaster Tim Harford discussed why the underlying technology might have much wider applications and the challenges that needed to be overcome. His first broadcast was on June 29, 2019.
The number of blockchain wallets quadrupled to 40 million between 2016 and 2020.A paper published in 2022 discussed the potential use of blockchain technology in sustainable management.
=== Cryptocurrencies ===
Most cryptocurrencies use blockchain technology to record transactions. For example, the bitcoin network and Ethereum network are both based on blockchain.
The criminal enterprise Silk Road, which operated on Tor, utilized cryptocurrency for payments, some of which the US federal government has seized through research on the blockchain and forfeiture.Governments have mixed policies on the legality of their citizens or banks owning cryptocurrencies. China implements blockchain technology in several industries including a national digital currency which launched in 2020. To strengthen their respective currencies, Western governments including the European Union and the United States have initiated similar projects.
=== Smart contracts ===
Blockchain-based smart contracts are proposed contracts that can be partially or fully executed or enforced without human interaction. One of the main objectives of a smart contract is automated escrow. A key feature of smart contracts is that they do not need a trusted third party (such as a trustee) to act as an intermediary between contracting entities — the blockchain network executes the contract on its own. This may reduce friction between entities when transferring value and could subsequently open the door to a higher level of transaction automation. An IMF staff discussion from 2018 reported that smart contracts based on blockchain technology might reduce moral hazards and optimize the use of contracts in general. But "no viable smart contract systems have yet emerged." Due to the lack of widespread use, their legal status was unclear.
=== Financial services ===
According to Reason, many banks have expressed interest in implementing distributed ledgers for use in banking and are cooperating with companies creating private blockchains, and according to a September 2016 IBM study, this is occurring faster than expected.Banks are interested in this technology not least because it has the potential to speed up back office settlement systems. Moreover, as the blockchain industry has reached early maturity institutional appreciation has grown that it is, practically speaking, the infrastructure of a whole new financial industry, with all the implications which that entails.Banks such as UBS are opening new research labs dedicated to blockchain technology in order to explore how blockchain can be used in financial services to increase efficiency and reduce costs.Berenberg, a German bank, believes that blockchain is an "overhyped technology" that has had a large number of "proofs of concept", but still has major challenges, and very few success stories.The blockchain has also given rise to initial coin offerings (ICOs) as well as a new category of digital asset called security token offerings (STOs), also sometimes referred to as digital security offerings (DSOs). STO/DSOs may be conducted privately or on public, regulated stock exchange and are used to tokenize traditional assets such as company shares as well as more innovative ones like intellectual property, real estate, art, or individual products. A number of companies are active in this space providing services for compliant tokenization, private STOs, and public STOs.
=== Games ===
Blockchain technology, such as cryptocurrencies and non-fungible tokens (NFTs), has been used in video games for monetization. Many live-service games offer in-game customization options, such as character skins or other in-game items, which the players can earn and trade with other players using in-game currency. Some games also allow for trading of virtual items using real-world currency, but this may be illegal in some countries where video games are seen as akin to gambling, and has led to gray market issues such as skin gambling, and thus publishers typically have shied away from allowing players to earn real-world funds from games. Blockchain games typically allow players to trade these in-game items for cryptocurrency, which can then be exchanged for money.The first known game to use blockchain technologies was CryptoKitties, launched in November 2017, where the player would purchase NFTs with Ethereum cryptocurrency, each NFT consisting of a virtual pet that the player could breed with others to create offspring with combined traits as new NFTs. The game made headlines in December 2017 when one virtual pet sold for more than US$100,000. CryptoKitties also illustrated scalability problems for games on Ethereum when it created significant congestion on the Ethereum network in early 2018 with approximately 30% of all Ethereum transactions being for the game.By the early 2020s, there had not been a breakout success in video games using blockchain, as these games tend to focus on using blockchain for speculation instead of more traditional forms of gameplay, which offers limited appeal to most players. Such games also represent a high risk to investors as their revenues can be difficult to predict. However, limited successes of some games, such as Axie Infinity during the COVID-19 pandemic, and corporate plans towards metaverse content, refueled interest in the area of GameFi, a term describing the intersection of video games and financing typically backed by blockchain currency, in the second half of 2021. Several major publishers, including Ubisoft, Electronic Arts, and Take Two Interactive, have stated that blockchain and NFT-based games are under serious consideration for their companies in the future.In October 2021, Valve Corporation banned blockchain games, including those using cryptocurrency and NFTs, from being hosted on its Steam digital storefront service, which is widely used for personal computer gaming, claiming that this was an extension of their policy banning games that offered in-game items with real-world value. Valve's prior history with gambling, specifically skin gambling, was speculated to be a factor in the decision to ban blockchain games. Journalists and players responded positively to Valve's decision as blockchain and NFT games have a reputation for scams and fraud among most PC gamers, and Epic Games, which runs the Epic Games Store in competition to Steam, said that they would be open to accepted blockchain games in the wake of Valve's refusal.
=== Supply chain ===
There have been several different efforts to employ blockchains in supply chain management.
Precious commodities mining — Blockchain technology has been used for tracking the origins of gemstones and other precious commodities. In 2016, The Wall Street Journal reported that the blockchain technology company Everledger was partnering with IBM's blockchain-based tracking service to trace the origin of diamonds to ensure that they were ethically mined. As of 2019, the Diamond Trading Company (DTC) has been involved in building a diamond trading supply chain product called Tracer.
Food supply — As of 2018, Walmart and IBM were running a trial to use a blockchain-backed system for supply chain monitoring for lettuce and spinach — all nodes of the blockchain were administered by Walmart and were located on the IBM cloud.
Fashion industry — There is an opaque relationship between brands, distributors, and customers in the fashion industry, which will prevent the sustainable and stable development of the fashion industry. Blockchain makes up for this shortcoming and makes information transparent, solving the difficulty of sustainable development of the industry.
Motor vehicles — Mercedes-Benz and partner Icertis developed a blockchain prototype used to facilitate consistent documentation of contracts along the supply chain so that the ethical standards and contractual obligations required of its direct suppliers can be passed on to second tier suppliers and beyond. In another project, the company uses blockchain technology to track the emissions of climate-relevant gases and the amount of secondary material along the supply chain for its battery cell manufacturers.
=== Domain names ===
There are several different efforts to offer domain name services via the blockchain. These domain names can be controlled by the use of a private key, which purports to allow for uncensorable websites. This would also bypass a registrar's ability to suppress domains used for fraud, abuse, or illegal content.Namecoin is a cryptocurrency that supports the ".bit" top-level domain (TLD). Namecoin was forked from bitcoin in 2011. The .bit TLD is not sanctioned by ICANN, instead requiring an alternative DNS root. As of 2015, .bit was used by 28 websites, out of 120,000 registered names. Namecoin was dropped by OpenNIC in 2019, due to malware and potential other legal issues. Other blockchain alternatives to ICANN include The Handshake Network, EmerDNS, and Unstoppable Domains.Specific TLDs include ".eth", ".luxe", and ".kred", which are associated with the Ethereum blockchain through the Ethereum Name Service (ENS). The .kred TLD also acts as an alternative to conventional cryptocurrency wallet addresses as a convenience for transferring cryptocurrency.
=== Other uses ===
Blockchain technology can be used to create a permanent, public, transparent ledger system for compiling data on sales, tracking digital use and payments to content creators, such as wireless users or musicians. The Gartner 2019 CIO Survey reported 2% of higher education respondents had launched blockchain projects and another 18% were planning academic projects in the next 24 months. In 2017, IBM partnered with ASCAP and PRS for Music to adopt blockchain technology in music distribution. Imogen Heap's Mycelia service has also been proposed as a blockchain-based alternative "that gives artists more control over how their songs and associated data circulate among fans and other musicians."New distribution methods are available for the insurance industry such as peer-to-peer insurance, parametric insurance and microinsurance following the adoption of blockchain. The sharing economy and IoT are also set to benefit from blockchains because they involve many collaborating peers. The use of blockchain in libraries is being studied with a grant from the U.S. Institute of Museum and Library Services.Other blockchain designs include Hyperledger, a collaborative effort from the Linux Foundation to support blockchain-based distributed ledgers, with projects under this initiative including Hyperledger Burrow (by Monax) and Hyperledger Fabric (spearheaded by IBM). Another is Quorum, a permissioned private blockchain by JPMorgan Chase with private storage, used for contract applications.Oracle introduced a blockchain table feature in its Oracle 21c database.Blockchain is also being used in peer-to-peer energy trading.Lightweight blockchains, or simplified blockchains, are more suitable for internet of things (IoT) applications than conventional blockchains. One experiment suggested that a lightweight blockchain-based network could accommodate up to 1.34 million authentication processes every second, which could be sufficient for resource-constrained IoT networks.Blockchain could be used in detecting counterfeits by associating unique identifiers to products, documents and shipments, and storing records associated with transactions that cannot be forged or altered. It is however argued that blockchain technology needs to be supplemented with technologies that provide a strong binding between physical objects and blockchain systems, as well as provisions for content creator verification ala KYC standards. The EUIPO established an Anti-Counterfeiting Blockathon Forum, with the objective of "defining, piloting and implementing" an anti-counterfeiting infrastructure at the European level. The Dutch Standardisation organisation NEN uses blockchain together with QR Codes to authenticate certificates.Beijing and Shanghai are among the cities designated by China to trial blockchain applications as January 30, 2022. In Chinese legal proceedings, blockchain technology was first accepted as a method for authenticating internet evidence by the Hangzhou Internet Court in 2019 and has since been accepted by other Chinese courts.: 123–125
== Blockchain interoperability ==
With the increasing number of blockchain systems appearing, even only those that support cryptocurrencies, blockchain interoperability is becoming a topic of major importance. The objective is to support transferring assets from one blockchain system to another blockchain system. Wegner stated that "interoperability is the ability of two or more software components to cooperate despite differences in language, interface, and execution platform". The objective of blockchain interoperability is therefore to support such cooperation among blockchain systems, despite those kinds of differences.
There are already several blockchain interoperability solutions available. They can be classified into three categories: cryptocurrency interoperability approaches, blockchain engines, and blockchain connectors.
Several individual IETF participants produced the draft of a blockchain interoperability architecture.
== Energy consumption concerns ==
Some cryptocurrencies use blockchain mining — the peer-to-peer computer computations by which transactions are validated and verified. This requires a large amount of energy. In June 2018, the Bank for International Settlements criticized the use of public proof-of-work blockchains for their high energy consumption.Early concern over the high energy consumption was a factor in later blockchains such as Cardano (2017), Solana (2020) and Polkadot (2020) adopting the less energy-intensive proof-of-stake model. Researchers have estimated that Bitcoin consumes 100,000 times as much energy as proof-of-stake networks.In 2021, a study by Cambridge University determined that Bitcoin (at 121 terawatt-hours per year) used more electricity than Argentina (at 121TWh) and the Netherlands (109TWh). According to Digiconomist, one bitcoin transaction required 708 kilowatt-hours of electrical energy, the amount an average U.S. household consumed in 24 days.In February 2021, U.S. Treasury secretary Janet Yellen called Bitcoin "an extremely inefficient way to conduct transactions", saying "the amount of energy consumed in processing those transactions is staggering". In March 2021, Bill Gates stated that "Bitcoin uses more electricity per transaction than any other method known to mankind", adding "It's not a great climate thing."Nicholas Weaver, of the International Computer Science Institute at the University of California, Berkeley, examined blockchain's online security, and the energy efficiency of proof-of-work public blockchains, and in both cases found it grossly inadequate. The 31TWh-45TWh of electricity used for bitcoin in 2018 produced 17-23 million tonnes of CO2. By 2022, the University of Cambridge and Digiconomist estimated that the two largest proof-of-work blockchains, Bitcoin and Ethereum, together used twice as much electricity in one year as the whole of Sweden, leading to the release of up to 120 million tonnes of CO2 each year.Some cryptocurrency developers are considering moving from the proof-of-work model to the proof-of-stake model.
== Academic research ==
In October 2014, the MIT Bitcoin Club, with funding from MIT alumni, provided undergraduate students at the Massachusetts Institute of Technology access to $100 of bitcoin. The adoption rates, as studied by Catalini and Tucker (2016), revealed that when people who typically adopt technologies early are given delayed access, they tend to reject the technology. Many universities have founded departments focusing on crypto and blockchain, including MIT, in 2017. In the same year, Edinburgh became "one of the first big European universities to launch a blockchain course", according to the Financial Times.
=== Adoption decision ===
Motivations for adopting blockchain technology (an aspect of innovation adoptation) have been investigated by researchers. For example, Janssen, et al. provided a framework for analysis, and Koens & Poll pointed out that adoption could be heavily driven by non-technical factors. Based on behavioral models, Li has discussed the differences between adoption at the individual level and organizational levels.
=== Collaboration ===
Scholars in business and management have started studying the role of blockchains to support collaboration. It has been argued that blockchains can foster both cooperation (i.e., prevention of opportunistic behavior) and coordination (i.e., communication and information sharing). Thanks to reliability, transparency, traceability of records, and information immutability, blockchains facilitate collaboration in a way that differs both from the traditional use of contracts and from relational norms. Contrary to contracts, blockchains do not directly rely on the legal system to enforce agreements. In addition, contrary to the use of relational norms, blockchains do not require a trust or direct connections between collaborators.
=== Blockchain and internal audit ===
The need for internal audits to provide effective oversight of organizational efficiency will require a change in the way that information is accessed in new formats. Blockchain adoption requires a framework to identify the risk of exposure associated with transactions using blockchain. The Institute of Internal Auditors has identified the need for internal auditors to address this transformational technology. New methods are required to develop audit plans that identify threats and risks. The Internal Audit Foundation study, Blockchain and Internal Audit, assesses these factors. The American Institute of Certified Public Accountants has outlined new roles for auditors as a result of blockchain.
=== Journals ===
In September 2015, the first peer-reviewed academic journal dedicated to cryptocurrency and blockchain technology research, Ledger, was announced. The inaugural issue was published in December 2016. The journal covers aspects of mathematics, computer science, engineering, law, economics and philosophy that relate to cryptocurrencies. The journal encourages authors to digitally sign a file hash of submitted papers, which are then timestamped into the bitcoin blockchain. Authors are also asked to include a personal bitcoin address on the first page of their papers for non-repudiation purposes.
== See also ==
Changelog – a record of all notable changes made to a project
Checklist – an informational aid used to reduce failure
Economics of digitization
List of blockchains
Privacy and blockchain
Version control – a record of all changes (mostly of software project) in a form of a graph
== References ==
== Further reading ==
== External links ==
Media related to Blockchain at Wikimedia Commons |
Ethereum | "Ethereum is a decentralized blockchain with smart contract functionality. Ether (Abbreviation: ETH;(...TRUNCATED) |
Charlie Lee (computer scientist) | "Charlie Lee is a computer scientist, best known as the creator of Litecoin. He serves as the managi(...TRUNCATED) |
Namecoin | "Namecoin (Abbreviation: NMC; sign: \n \n \n \n \n N\n \n \n (...TRUNCATED) |
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Wikipedia Crypto Articles 🪙₿
This dataset is a collection of articles obtained from Wikipedia on January 5ᵗʰ, 2024. It contains two columns, title and article, containing the article's title as it is on the Wikipedia website and the article's content.
The articles vary from specific cryptocurrencies—such as Bitcoin or Ethereum—to historical facts, companies, exchanges, entities, and relevant people in the history of cryptocurrencies.
This dataset can be used to train machine learning models for question-answering tasks, summarization, conversation, named entity recognition, etc.
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