Ethereum is a
decentralized
Decentralization or decentralisation is the process by which the activities of an organization, particularly those related to planning and decision-making, are distributed or delegated away from a central, authoritative location or group and gi ...
blockchain
The blockchain is a distributed ledger with growing lists of Record (computer science), records (''blocks'') that are securely linked together via Cryptographic hash function, cryptographic hashes. Each block contains a cryptographic hash of th ...
with
smart contract
A smart contract is a computer program or a Transaction Protocol Data Unit, transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. The objective ...
functionality. Ether (
abbreviation
An abbreviation () is a shortened form of a word or phrase, by any method including shortening (linguistics), shortening, contraction (grammar), contraction, initialism (which includes acronym), or crasis. An abbreviation may be a shortened for ...
: ETH) is the native
cryptocurrency
A cryptocurrency (colloquially crypto) is a digital currency designed to work through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it.
Individual coin ownership record ...
of the platform. Among cryptocurrencies, ether is second only to
bitcoin
Bitcoin (abbreviation: BTC; Currency symbol, sign: ₿) is the first Decentralized application, decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown entity published a white paper under ...
in
market capitalization
Market capitalization, sometimes referred to as market cap, is the total value of a publicly traded company's outstanding common shares owned by stockholders.
Market capitalization is equal to the market price per common share multiplied by ...
.
It is
open-source software
Open-source software (OSS) is Software, computer software that is released under a Open-source license, license in which the copyright holder grants users the rights to use, study, change, and Software distribution, distribute the software an ...
.
Ethereum was conceived in 2013 by
programmer
A programmer, computer programmer or coder is an author of computer source code someone with skill in computer programming.
The professional titles Software development, ''software developer'' and Software engineering, ''software engineer' ...
Vitalik Buterin
Vitaly Dmitrievich Buterin (; born 31 January 1994), better known as Vitalik Buterin (), is a Canadian computer programmer and co-founder of Ethereum. Buterin became involved with cryptocurrency early in its inception, co-founding ''Bitcoin Ma ...
. Other founders include
Gavin Wood
Gavin James Wood is an English computer scientist, a co-founder of Ethereum, and creator of Polkadot and Kusama.
Early life
Wood was born in Lancaster, England, United Kingdom. He attended the Lancaster Royal Grammar School. He graduated from ...
,
Charles Hoskinson
Charles Hoskinson (born 1987) is an Americans, American Businessperson, entrepreneur who is a co-founder of the blockchain engineering company IOHK, and the Cardano (blockchain platform), Cardano blockchain platform, and was a co-founder of the ...
,
Anthony Di Iorio
Anthony Di Iorio is a Canadian entrepreneur primarily known as a co-founder of Ethereum and an early investor in Bitcoin. Di Iorio is the founder and CEO of the blockchain company Decentral, and the associated Jaxx wallet. He also served as the fi ...
, and
Joseph Lubin.
In 2014,
development
Development or developing may refer to:
Arts
*Development (music), the process by which thematic material is reshaped
* Photographic development
*Filmmaking, development phase, including finance and budgeting
* Development hell, when a proje ...
work began and was
crowdfunded
Crowdfunding is the practice of funding a project or venture by raising money from a large number of people, typically via the internet. Crowdfunding is a form of crowdsourcing and alternative finance, to fund projects "without standard financial ...
, and the network went live on 30 July 2015. Ethereum allows anyone to deploy
decentralized application
A decentralised application (DApp, dApp, Dapp, or dapp) is an Application software, application that can operate autonomously, typically through the use of smart contracts, that run on a decentralized computing, blockchain or other distributed le ...
s onto it, with which users can interact.
Decentralized finance
Decentralized finance (often stylized as DeFi) provides financial instruments and services through smart contracts on a programmable, permissionless blockchain. This approach reduces the need for intermediaries such as brokerages, exchanges, or ...
(DeFi) applications provide
financial instrument
Financial instruments are monetary contracts between parties. They can be created, traded, modified and settled. They can be cash (currency), evidence of an ownership, interest in an entity or a contractual right to receive or deliver in the form ...
s that do not directly rely on
financial intermediaries
A financial intermediary is an institution or individual that serves as a "Intermediary, middleman" among diverse parties in order to facilitate financial transactions. Common types include commercial banks, investment banks, stockbrokers, insura ...
like
brokerage
A broker is a person or entity that arranges transactions between a buyer and a seller. This may be done for a commission when the deal is executed. A broker who also acts as a seller or as a buyer becomes a principal party to the deal. Neith ...
s,
exchanges, or
bank
A bank is a financial institution that accepts Deposit account, deposits from the public and creates a demand deposit while simultaneously making loans. Lending activities can be directly performed by the bank or indirectly through capital m ...
s. This facilitates borrowing against cryptocurrency holdings or lending them out for
interest
In finance and economics, interest is payment from a debtor or deposit-taking financial institution to a lender or depositor of an amount above repayment of the principal sum (that is, the amount borrowed), at a particular rate. It is distinct f ...
.
Ethereum also allows users to create and exchange
non-fungible token
A non-fungible token (NFT) is a unique digital identifier that is recorded on a blockchain and is used to certify ownership and authenticity. It cannot be copied, substituted, or subdivided. The ownership of an NFT is recorded in the blockchai ...
s (NFTs), which are tokens that can be tied to unique digital assets, such as images. Additionally, many other cryptocurrencies utilize the ERC-20 token standard on top of the Ethereum blockchain and have utilized the platform for
initial coin offering
An initial coin offering (ICO) or initial currency offering is a type of funding using cryptocurrencies. It is often a form of crowdfunding, although a private ICO which does not seek public investment is also possible. In an ICO, a quantity of c ...
s.
On 15 September 2022, Ethereum transitioned its
consensus mechanism from
proof-of-work
Proof of work (also written as proof-of-work, an abbreviated PoW) is a form of Cryptography, cryptographic proof (truth), proof in which one party (the ''prover'') proves to others (the ''verifiers'') that a certain amount of a specific computatio ...
(PoW) to
proof-of-stake
Proof-of-stake (PoS) protocols are a class of consensus mechanisms for blockchains that work by selecting validators in proportion to their quantity of holdings in the associated cryptocurrency. This is done to avoid the computational cost of ...
(PoS) in an update known as "The Merge", which cut the blockchain's energy usage by 99%.
History
Founding (2013–2014)
Ethereum was initially described in late 2013 in a
white paper
A white paper is a report or guide that informs readers concisely about a complex issue and presents the issuing body's philosophy on the matter. It is meant to help readers understand an issue, solve a problem, or make a decision. Since the 199 ...
by
Vitalik Buterin
Vitaly Dmitrievich Buterin (; born 31 January 1994), better known as Vitalik Buterin (), is a Canadian computer programmer and co-founder of Ethereum. Buterin became involved with cryptocurrency early in its inception, co-founding ''Bitcoin Ma ...
, a programmer and co-founder of ''
Bitcoin Magazine'', that described a way to build
decentralized
Decentralization or decentralisation is the process by which the activities of an organization, particularly those related to planning and decision-making, are distributed or delegated away from a central, authoritative location or group and gi ...
applications.
Buterin argued to the
Bitcoin Core
Bitcoin Core is free and open-source software that serves as a bitcoin node (the set of which form the Bitcoin network) and provides a bitcoin wallet which fully verifies payments. It is considered to be bitcoin's reference implementation. Ini ...
developers that blockchain technology could benefit from other applications besides money and that it needed a more robust language for application development
that could lead to real-world assets, such as stocks and property, to the blockchain.
In 2013, Buterin briefly worked with
eToro
eToro Group Ltd. is an Israel, Israeli multi-asset Investment management, investment and social trading company focused on providing Financial trading, financial services. eToro was founded in 2007 in Tel Aviv by Yoni Assia, Ronen Assia, and Da ...
CEO Yoni Assia on the
Colored Coins project and drafted its white paper outlining additional use cases for blockchain technology. However, after failing to gain agreement on how the project should proceed, he proposed the development of a new platform with a more robust scripting language—a
Turing-complete
In computability theory, a system of data-manipulation rules (such as a model of computation, a computer's instruction set, a programming language, or a cellular automaton) is said to be Turing-complete or computationally universal if it can be ...
programming language—that would eventually become Ethereum.
Ethereum was announced at the North American Bitcoin Conference in Miami, in January 2014.
During the conference,
Gavin Wood
Gavin James Wood is an English computer scientist, a co-founder of Ethereum, and creator of Polkadot and Kusama.
Early life
Wood was born in Lancaster, England, United Kingdom. He attended the Lancaster Royal Grammar School. He graduated from ...
,
Charles Hoskinson
Charles Hoskinson (born 1987) is an Americans, American Businessperson, entrepreneur who is a co-founder of the blockchain engineering company IOHK, and the Cardano (blockchain platform), Cardano blockchain platform, and was a co-founder of the ...
, and
Anthony Di Iorio
Anthony Di Iorio is a Canadian entrepreneur primarily known as a co-founder of Ethereum and an early investor in Bitcoin. Di Iorio is the founder and CEO of the blockchain company Decentral, and the associated Jaxx wallet. He also served as the fi ...
(who financed the project) rented a house in Miami with Buterin at which they could develop a fuller sense of what Ethereum might become.
Di Iorio invited friend
Joseph Lubin, who invited reporter Morgen Peck, to bear witness.
Peck subsequently wrote about the experience in ''
Wired
Wired may refer to:
Arts, entertainment, and media Music
* ''Wired'' (Jeff Beck album), 1976
* ''Wired'' (Hugh Cornwell album), 1993
* ''Wired'' (Mallory Knox album), 2017
* "Wired", a song by Prism from their album '' Beat Street''
* "Wired ...
''. Six months later the founders met again in
Zug
Zug (Standard German: , Alemannic German: ; ; ; ; )Named in the 16th century. is the largest List of cities in Switzerland, town and capital of the Swiss canton of Zug. Zug is renowned as a hub for some of the wealthiest individuals in the wor ...
, Switzerland, where Buterin told the founders that the project would proceed as a non-profit. Hoskinson left the project at that time and soon after founded IOHK, a blockchain company responsible for
Cardano.
Ethereum has an unusually long list of founders.
Anthony Di Iorio wrote: "Ethereum was founded by Vitalik Buterin, Myself, Charles Hoskinson, Mihai Alisie & Amir Chetrit (the initial 5) in December 2013. Joseph Lubin, Gavin Wood, & Jeffrey Wilcke were added in early 2014 as founders." Buterin chose the name Ethereum after browsing
a list of elements from science fiction on
Wikipedia
Wikipedia is a free content, free Online content, online encyclopedia that is written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and the wiki software MediaWiki. Founded by Jimmy Wales and La ...
. He stated, "I immediately realized that I liked it better than all of the other alternatives that I had seen; I suppose it was that
tsounded nice and it had the word '
ether
In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R� ...
', referring to the hypothetical invisible medium that permeates the universe and allows light to travel."
Buterin wanted his platform to be the underlying and imperceptible medium for the applications running on top of it.
Development (2014)
Formal development of the software underlying Ethereum began in early 2014 through a Swiss company, Ethereum Switzerland GmbH (''EthSuisse'').
The idea of putting executable
smart contract
A smart contract is a computer program or a Transaction Protocol Data Unit, transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. The objective ...
s in the blockchain needed to be specified before it could be implemented in software. This work was done by Gavin Wood, then the
chief technology officer, in the Ethereum Yellow Paper that specified the Ethereum Virtual Machine.
[ Subsequently, a Swiss non-profit foundation, the Ethereum Foundation (''Stiftung Ethereum''), was founded. Development was funded by an online public crowd sale from July to August 2014, in which participants bought the Ethereum value token (ether) with another digital currency, ]bitcoin
Bitcoin (abbreviation: BTC; Currency symbol, sign: ₿) is the first Decentralized application, decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown entity published a white paper under ...
. While there was early praise for the technical innovations of Ethereum, questions were also raised about its security and scalability.
The Foundation funded multiple teams in different cities building three separate implementations of the protocol: Geth ( Go), Pyethereum (Python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (prog ...
), a C++ implementation, and also Swarm ( decentralized file storage), Mist Browser
Mist is a phenomenon caused by small droplets of water suspended in the cold air, usually by condensation. Physically, it is an example of a dispersion. It is most commonly seen where water vapor in warm, moist air meets sudden cooling, such as ...
(A wallet, browser and a user interface for smart contracts, now defunct) among other projects. The intended purpose of the three distinct implementations would be so that if one of them had a bug, the other two could be used as a comparison.
Launch and the DAO event (2014–2016)
Several codenamed prototypes of Ethereum were developed over 18 months in 2014 and 2015 by the Ethereum Foundation as part of their proof-of-concept
A proof of concept (POC or PoC), also known as proof of principle, is an inchoate realization of a certain idea or method in order to demonstrate its feasibility or viability. A proof of concept is usually small and may or may not be complete ...
series. "Olympic" was the last prototype and public beta pre-release. The Olympic network gave users a bug bounty of 25,000 ether for stress-testing the Ethereum blockchain. On 30 July 2015, "Frontier" marked the official launch of the Ethereum platform, and Ethereum created its "genesis block". The genesis block contained 8,893 transactions allocating various amounts of ether to different addresses, and a block reward of 5 ETH.
Since the initial launch, Ethereum has undergone a number of planned protocol upgrades, which are important changes affecting the underlying functionality and/or incentive structures of the platform. Protocol upgrades are accomplished by means of a hard fork.
In 2016, a decentralized autonomous organization
A decentralized autonomous organization (DAO), sometimes called a decentralized autonomous corporation (DAC), is an organization managed in whole or in part by decentralized computer programs, with voting and finances handled through a decent ...
called The DAO—a set of smart contracts developed on the platform—raised a record in a crowd sale to fund the project. Emin Gün Sirer
Emin Gün Sirer is a Turkish-American computer scientist. Sirer developed the Avalanche Consensus protocol underlying the Avalanche blockchain platform, and is currently the CEO and co-founder of Ava Labs. He was an associate professor of com ...
, Vlad Zamfir and Dino Mark had written a paper called ''A Call for a Temporary Moratorium on The DAO'' in which they described in which way the DAO might be vunerable to attacks. The DAO was exploited in June 2016 when of DAO tokens were stolen by an unknown hacker. The event sparked a debate in the crypto-community about whether Ethereum should perform a contentious "hard fork" to reappropriate the affected funds. The fork resulted in the network splitting into two blockchains: Ethereum with the theft reversed, and Ethereum Classic
Ethereum Classic is a blockchain-based distributed computing platform that offers smart contract (scripting) functionality. It is open source and supports a modified version of Nakamoto consensus via transaction-based state transitions executed ...
which continued on the original chain.
Continued development and milestones (2017–present)
In March 2017, various blockchain
The blockchain is a distributed ledger with growing lists of Record (computer science), records (''blocks'') that are securely linked together via Cryptographic hash function, cryptographic hashes. Each block contains a cryptographic hash of th ...
startups, research groups, and ''Fortune'' 500 companies announced the creation of the Enterprise Ethereum Alliance (EEA) with 30 founding members. By May 2017, the nonprofit organization had 116 enterprise members, including ConsenSys, CME Group
CME Group Inc. is an American financial services company based in Chicago that operates financial derivatives exchanges including the Chicago Mercantile Exchange, Chicago Board of Trade, New York Mercantile Exchange, and the Commodity Exchange. ...
, Cornell University's research group, Toyota Research Institute, Samsung SDS
Samsung SDS Co., Ltd. (formerly Samsung Data Systems; ), Established in 1985 as a subsidiary of Samsung Group, is a provider of Information Technology (IT) services, including consulting, technical, and outsourcing services. SDS is also active ...
, Microsoft
Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...
, Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...
, J. P. Morgan
John Pierpont Morgan Sr. (April 17, 1837 – March 31, 1913) was an American financier and investment banker who dominated corporate finance on Wall Street throughout the Gilded Age and Progressive Era. As the head of the banking firm that ...
, Cooley LLP
Cooley LLP is an American international law firm, headquartered in Palo Alto, California, with offices worldwide. The firm's practice areas include corporate, litigation, intellectual property, fund formation, public markets, employment, life ...
, Merck KGaA
The Merck Group, branded and commonly known as Merck, is a German Multinational corporation, multinational science and technology company headquartered in Darmstadt, with about 60,000 employees and a presence in 66 countries. The group include ...
, DTCC, Deloitte
Deloitte is a multinational professional services network based in London, United Kingdom. It is the largest professional services network in the world by revenue and number of employees, and is one of the Big Four accounting firms, along wi ...
, Accenture
Accenture plc is a global multinational professional services company originating in the United States and headquartered in Dublin, Ireland, that specializes in information technology (IT) services and management consulting. It was founded in 1 ...
, Banco Santander
Banco Santander S.A. trading as Santander Group ( , , ), is a Spanish multinational financial services company based in Santander, with operative offices in Madrid. Additionally, Santander maintains a presence in most global financial centres ...
, BNY Mellon
The Bank of New York Mellon Corporation, commonly known as BNY, is an American international financial services company headquartered in New York City. It was established in its current form in July 2007 by the merger of the Bank of New York an ...
, ING
Ing, ING or ing may refer to:
Art and media
* '' ...ing'', a 2003 Korean film
* i.n.g, a Taiwanese girl group
* The Ing, a race of dark creatures in the 2004 video game '' Metroid Prime 2: Echoes''
* "Ing", the first song on The Roches' 199 ...
, and National Bank of Canada
The National Bank of Canada () is the sixth largest commercial bank in Canada. It is headquartered in Montreal, and has branches in most Canadian provinces and 2.4 million personal clients. National Bank is the largest bank in Quebec, and the se ...
. By July 2017, there were over 150 members in the alliance, including MasterCard, Cisco Systems
Cisco Systems, Inc. (using the trademark Cisco) is an American multinational corporation, multinational digital communications technology conglomerate (company), conglomerate corporation headquartered in San Jose, California. Cisco develops, m ...
, Sberbank
The Public JSC Sberbank (, initially a contraction of ) is a Russian majority state-owned banking and financial services company headquartered in Moscow. As the Russian successor entity of the State Labor Savings Banks System of the USSR, it was ...
, and Scotiabank
The Bank of Nova Scotia (), operating as Scotiabank (), is a Canadian multinational corporation, multinational banking and financial services company headquartered in Toronto, Ontario. One of Canada's Big Five (banks), Big Five banks, it is the ...
.
In 2024, Paul Brody, EEA board member for EY, was announced as the new chairperson, and Karen Scarbrough, board member for Microsoft, as the new executive director. Vanessa Grellet from Arche Capital also joined as a new board member.
''CryptoKitties'' and the ERC-721 NFT standard
In 2017, '' CryptoKitties'', the blockchain game and decentralized application
A decentralised application (DApp, dApp, Dapp, or dapp) is an Application software, application that can operate autonomously, typically through the use of smart contracts, that run on a decentralized computing, blockchain or other distributed le ...
(dApp) featuring digital cat artwork as NFTs, was launched on the Ethereum network. In cultivating popularity with users and collectors, it gained notable mainstream media attention providing significant exposure to Ethereum in the process. It was considered the most popular smart contract in use on the network but it also highlighted concerns over Ethereum's scalability due to the game's substantial consumption of network capacity at the time.
In January 2018, a community-driven paper (an EIP, "Ethereum Improvement Proposal") under the leadership of civic hacker and lead author William Entriken was published, called ''ERC-721: Non-Fungible Token Standard.'' It introduced ERC-721, the first official NFT standard on Ethereum. This standardization allowed Ethereum to become central to a multi-billion dollar digital collectibles market.
Continued developments
By January 2018, ether was the second-largest cryptocurrency in terms of market capitalization, behind bitcoin. , it maintained that relative position.
In 2019, Ethereum Foundation employee Virgil Griffith was arrested by the US government for presenting at a blockchain conference in North Korea. He would later plead guilty to one count of conspiring to violate the International Emergency Economic Powers Act in 2021.
In March 2021, Visa Inc.
Visa Inc. () is an American multinational payment card services corporation headquartered in San Francisco, California. It facilitates electronic funds transfers throughout the world, most commonly through Visa-branded credit cards, debit c ...
announced that it began settling stablecoin
A stablecoin is a type of cryptocurrency where the value of the digital asset is supposed to be pegged to a reference asset, which is either fiat money, exchange-traded commodities (such as precious metals or industrial metals), or another cry ...
transactions using Ethereum. In April 2021, JP Morgan Chase
JPMorgan Chase & Co. (stylized as JPMorganChase) is an American multinational finance corporation headquartered in New York City and incorporated in Delaware. It is the largest bank in the United States, and the world's largest bank by mark ...
, UBS
UBS Group AG (stylized simply as UBS) is a multinational investment bank and financial services firm founded and based in Switzerland, with headquarters in both Zurich and Basel. It holds a strong foothold in all major financial centres as the ...
, and MasterCard announced that they were investing into ConsenSys, a software development firm that builds Ethereum-related infrastructure.
There were two network upgrades in 2021. The first was "Berlin", implemented on 14 April 2021. The second was "London", which took effect on 5 August. The London upgrade included Ethereum Improvement Proposal ("EIP") 1559, a mechanism for reducing transaction fee volatility. The mechanism causes a portion of the ether paid in transaction fees for each block to be destroyed rather than given to the block proposer, reducing the inflation rate of ether and potentially resulting in periods of deflation.
On 27 August 2021, the blockchain experienced a brief fork
In cutlery or kitchenware, a fork (from 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tines with which one can spear foods either to h ...
that was the result of clients running different incompatible software versions.
The Merge: Transition from Proof-of-Work to Proof-of-Stake
"The Merge" (formerly called Ethereum 2.0) was a set of three updates (Bellatrix, Paris, and Shapella) that transitioned Ethereum's consensus protocol from Proof-of-Work to Proof-of-Stake. Bellatrix updated the Proof-of-Stake Beacon chain and introduced economic slashing. Paris was the event at block 15537393 on 15th September 2022 that merged Ethereum to the Beacon chain. Shapella (Shanghai-Capella) was the update that allowed for staking withdrawals.
The switch from proof-of-work to proof-of-stake on 15 September 2022 has cut Ethereum's energy usage by over 99%. However, the impact this has on global energy consumption
World energy supply and consumption refers to the global supply of World energy resources, energy resources and its Energy consumption, consumption. The system of global energy supply consists of the energy development, Refineries, refinement, a ...
and climate change may be limited since the computers previously used for mining ether may be used to mine other cryptocurrencies that are energy-intensive.
Post-Merge updates
Dencun
On March 13, 2024, "Dencun" or also "Deneb-Cancun" set of upgrade went live. These included EIP-4844 (Proto-Danksharding) which introduced "blobs" that could be used for general-purpose data-availability. Because "Blob" data is only stored temporarily, it is much cheaper than using normal call data for storage. This allows for L2 networks to greatly reduce the cost of posting compressed transaction data to L1.
Pectra
According to Ethereum.org, Prague-Electra ("Pectra") is expected to be launched in mid-2025. It brings various updates, including EIP-7251, which increases the staking amount per validator from exactly 32 ETH to anywhere between 32 ETH to 2048 ETH, and EIP-7702, which allows for the EOA addresses to use functionality from a smart contract.
Design
Overview
Ethereum is a peer-to-peer network
Peer-to-peer (P2P) computing or networking is a distributed application
Distributed computing is a field of computer science that studies distributed systems, defined as computer systems whose inter-communicating components are located on d ...
that maintains a database
In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...
containing the storage values of all Ethereum accounts and processes state-altering transactions. Approximately every 12 seconds, a batch of new transactions, known as a "block", is processed by the network. Each block contains a cryptographic hash
A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with a fixed size of n bits) that has special properties desirable for a cryptographic application:
* the probability of a particu ...
identifying the series of blocks that must precede it if the block is to be considered valid. This series of blocks is known as the blockchain
The blockchain is a distributed ledger with growing lists of Record (computer science), records (''blocks'') that are securely linked together via Cryptographic hash function, cryptographic hashes. Each block contains a cryptographic hash of th ...
.
Each "node" (network participant) connects with a relatively small subset of the network to offer blocks and unvalidated transactions (i.e. transactions not yet in the blockchain) to its peers for download, and it downloads any of these from its peers that it doesn't already have. Each node usually has a unique set of peers, so that offering an item to its peers results in the propagation of that item throughout the entire network within seconds. A node's collection of unvalidated transactions is known as its "mempool".
A node may choose to create a copy of the state for itself. It does this by starting with the genesis state and executing every transaction in the blockchain, in the proper order of blocks and in the order they are listed within each block.
Any Ethereum account may "stake" (deposit) 32 ETH to become a validator. At the end of each "epoch" (32 block slots, each slot lasting 12 seconds), each validator is pseudorandomly assigned to one of the slots of the epoch after the next, either as the block proposer or as an attester. During a slot, the block proposer uses their mempool to create a block that is intended to become the new "head" (latest block) of the blockchain, and the attesters attest to which block is at the head of the chain. If a validator makes self-contradicting proposals or attestations, or if it is inactive, it loses a portion of its stake. It may add to its stake at any time. A validator's attestation is given a weight equal to its stake or 32, whichever is less. According to the Ethereum protocol, the blockchain with the highest accumulated weight of attestations at any given time is to be regarded as the canonical chain. Validators are rewarded for making valid proposals and attestations. A validator's rewards are paid via transactions within the same chain that contains their proposal or attestation, and therefore would have little or no market value unless that chain becomes the canonical chain. This incentivizes validators to support the chain that they think other validators view as the canonical chain, which results in a high degree of consensus.
Ether
Ether (ETH) is the cryptocurrency generated in accordance with the Ethereum protocol as a reward to validators in a proof-of-stake
Proof-of-stake (PoS) protocols are a class of consensus mechanisms for blockchains that work by selecting validators in proportion to their quantity of holdings in the associated cryptocurrency. This is done to avoid the computational cost of ...
system for adding blocks to the blockchain. Ether is represented in the state as an unsigned integer
An integer is the number zero (0), a positive natural number (1, 2, 3, ...), or the negation of a positive natural number (−1, −2, −3, ...). The negations or additive inverses of the positive natural numbers are referred to as negative in ...
associated with each account, this being the account's ETH balance denominated in wei (1018 wei = 1 ether). At the end of each epoch, new ETH is generated by the addition of protocol-specified amounts to the balances of all validators that made valid block proposals or attestations in the epoch before the last (i.e. the epoch being finalized). Additionally, ether is the only currency accepted by the protocol as payment for the transaction fee. The transaction fee is composed of two parts: the base fee and the tip. The base fee is "burned" (deleted from existence) and the tip goes to the block proposer. The validator reward together with the tips provide the incentive to validators to keep the blockchain growing (i.e. to keep processing new transactions). Therefore, ETH is fundamental to the operation of the network. Ether may be "sent" from one account to another via a transaction, the execution of which simply entails subtracting the ''amount to be sent'' from the sender's balance and adding the same amount to the recipient's balance.
Ether is often erroneously referred to as "Ethereum".
The uppercase Greek letter Xi, Ξ, is sometimes used as a currency symbol
A currency symbol or currency sign is a graphic symbol used to denote a currency unit. Usually it is defined by a monetary authority, such as the national central bank for the currency concerned.
A symbol may be positioned in various ways, acc ...
for ether.
Accounts
There are two types of accounts on Ethereum: user accounts (also known as externally-owned accounts), and contract accounts. Both types have an ETH balance, may transfer ETH to any account, may execute the code of another contract, or create a new contract, and are identified on the blockchain and in the state by an account address.
Contracts are the only type of account that has associated bytecode
Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normal ...
and storage (to store contract-specific state). The code of a contract is evaluated when a transaction is sent to it. The code of the contract may read user-specified data from the transaction, and may have a return value
In computer programming, a return statement causes execution to leave the current subroutine and resume at the point in the code immediately after the instruction which called the subroutine, known as its return address. The return address is sav ...
. In addition to control flow
In computer science, control flow (or flow of control) is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated. The emphasis on explicit control flow distinguishes an '' ...
statements, the bytecode may include instructions to send ETH, read from and write to the contract's storage, create temporary storage (memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...
) that vanishes at the end of code evaluation, perform arithmetic
Arithmetic is an elementary branch of mathematics that deals with numerical operations like addition, subtraction, multiplication, and division. In a wider sense, it also includes exponentiation, extraction of roots, and taking logarithms.
...
and hashing operations, send transaction-like calls to other contracts (thus executing their code), create new contracts, and query information about the current transaction or the blockchain.
Addresses
Ethereum addresses are composed of the prefix "0x
" (a common identifier for hexadecimal
Hexadecimal (also known as base-16 or simply hex) is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of sixteen. Unlike the decimal system representing numbers using ten symbo ...
) concatenated with the rightmost 20 bytes of the Keccak-256 hash of the ECDSA
In cryptography, the Elliptic Curve Digital Signature Algorithm (ECDSA) offers a variant of the Digital Signature Algorithm (DSA) which uses elliptic-curve cryptography.
Key and signature sizes
As with elliptic-curve cryptography in general, the ...
public key
Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...
(the curve used is the so-called ''secp256k1''). In hexadecimal, two digits represent a byte, and so addresses contain 40 hexadecimal digits after the "0x
", e.g. 0xb794f5ea0ba39494ce839613fffba74279579268
. Contract addresses are in the same format, however, they are determined by sender and creation transaction nonce.
Virtual machine
The Ethereum Virtual Machine (EVM) is the runtime environment for transaction execution in Ethereum. The EVM is a stack
Stack may refer to:
Places
* Stack Island, an island game reserve in Bass Strait, south-eastern Australia, in Tasmania’s Hunter Island Group
* Blue Stack Mountains, in Co. Donegal, Ireland
People
* Stack (surname) (including a list of people ...
based virtual machine with an instruction set
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, s ...
specifically designed for Ethereum. The instruction set includes, among other things, stack operations, memory operations, and operations to inspect the current execution context, such as remaining gas, information about the current block, and the current transaction. The EVM is designed to be deterministic
Determinism is the metaphysical view that all events within the universe (or multiverse) can occur only in one possible way. Deterministic theories throughout the history of philosophy have developed from diverse and sometimes overlapping mo ...
on a wide variety of hardware and operating system
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
s, so that given a pre-transaction state and a transaction, each node produces the same post-transaction state, thereby enabling network consensus. The formal definition of the EVM is specified in the Ethereum Yellow Paper. EVMs have been implemented in C++, C#, Go, Haskell
Haskell () is a general-purpose, statically typed, purely functional programming language with type inference and lazy evaluation. Designed for teaching, research, and industrial applications, Haskell pioneered several programming language ...
, Java
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...
, JavaScript
JavaScript (), often abbreviated as JS, is a programming language and core technology of the World Wide Web, alongside HTML and CSS. Ninety-nine percent of websites use JavaScript on the client side for webpage behavior.
Web browsers have ...
, Python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (prog ...
, Ruby
Ruby is a pinkish-red-to-blood-red-colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapph ...
, Rust
Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH) ...
, Elixir
An elixir is a sweet liquid used for medical purposes, to be taken orally and intended to cure one's illness. When used as a dosage form, pharmaceutical preparation, an elixir contains at least one active ingredient designed to be taken orall ...
, Erlang, and soon WebAssembly
WebAssembly (Wasm) defines a portable binary-code format and a corresponding text format for executable programs as well as software interfaces for facilitating communication between such programs and their host environment.
The main goal of ...
.
Gas
Gas is a unit of account
In economics, unit of account is one of the functions of money. A unit of account is a standard numerical monetary unit of measurement of the market value of goods, services, and other transactions. Also known as a "measure" or "standard" of ...
within the EVM used in the calculation of the transaction fee, which is the amount of ETH a transaction's sender must pay to the network to have the transaction included in the blockchain. Each type of operation which may be performed by the EVM is hardcoded with a certain gas cost, which is intended to be roughly proportional to the monetary value of the resources (e.g. computation
A computation is any type of arithmetic or non-arithmetic calculation that is well-defined. Common examples of computation are mathematical equation solving and the execution of computer algorithms.
Mechanical or electronic devices (or, hist ...
and storage) a node must expend or dedicate to perform that operation.
When a sender is creating a transaction, the sender must specify a ''gas limit'' and ''gas price''. The ''gas limit'' is the maximum amount of gas the sender is willing to use in the transaction, and the ''gas price'' is the amount of ETH the sender wishes to pay to the network per unit of gas used. A transaction may only be included in the blockchain at a block slot that has a ''base gas price'' less than or equal to the transaction's ''gas price''. The portion of the ''gas price'' that is in excess of the ''base gas price'' is known as the tip and goes to the block proposer; the higher the tip, the more incentive a block proposer has to include the transaction in their block, and thus the quicker the transaction will be included in the blockchain. The sender buys the full amount of gas (i.e. their ETH balance is debited ''gas limit'' × ''gas price'' and their gas balance is set to ''gas limit'') up-front, at the start of the execution of the transaction, and is refunded at the end for any unused gas. If at any point the transaction does not have enough gas to perform the next operation, the transaction is reverted but the sender is still only refunded for the unused gas. In user interface
In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine fro ...
s, gas prices are typically denominated in gigawei (Gwei), a subunit of ETH equal to 10−9 ETH.
Applications
The EVM's instruction set
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, s ...
is Turing-complete
In computability theory, a system of data-manipulation rules (such as a model of computation, a computer's instruction set, a programming language, or a cellular automaton) is said to be Turing-complete or computationally universal if it can be ...
.[ Popular uses of Ethereum have included the creation of fungible (ERC-20) and non-fungible (ERC-721) tokens with a variety of properties, ]crowdfunding
Crowdfunding is the practice of funding a project or venture by raising money from a large number of people, typically via the internet. Crowdfunding is a form of crowdsourcing and Alternative Finance, alternative finance, to fund projects "withou ...
(e.g. initial coin offerings
In a written or published work, an initial is a letter at the beginning of a word, a chapter, or a paragraph that is larger than the rest of the text. The word is ultimately derived from the Latin ''initiālis'', which means ''of the beginning ...
), decentralized finance
Decentralized finance (often stylized as DeFi) provides financial instruments and services through smart contracts on a programmable, permissionless blockchain. This approach reduces the need for intermediaries such as brokerages, exchanges, or ...
, decentralized exchanges, decentralized autonomous organization
A decentralized autonomous organization (DAO), sometimes called a decentralized autonomous corporation (DAC), is an organization managed in whole or in part by decentralized computer programs, with voting and finances handled through a decent ...
s (DAOs), games, prediction market
Prediction markets, also known as betting markets, information markets, decision markets, idea futures or event derivatives, are open markets that enable the prediction of specific outcomes using financial incentives. They are exchange-traded mar ...
s, and gambling.
Contract source code
Ethereum's smart contracts are written in high-level
High-level and low-level, as technical terms, are used to classify, describe and point to specific goals of a systematic operation; and are applied in a wide range of contexts, such as, for instance, in domains as widely varied as computer scienc ...
programming languages and then compiled down to EVM bytecode
Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normal ...
, which is then deployed to the Ethereum blockchain. They can be written in Solidity
Solidity is a programming language for implementing smart contracts on various blockchain platforms, most notably, Ethereum. Solidity is licensed under GNU General Public License v3.0. Solidity was designed by Gavin Wood and developed by Chri ...
(a language library with similarities to C and JavaScript
JavaScript (), often abbreviated as JS, is a programming language and core technology of the World Wide Web, alongside HTML and CSS. Ninety-nine percent of websites use JavaScript on the client side for webpage behavior.
Web browsers have ...
), as well as others. Source code and compiler information are usually published on blockchain explorer websites soon after the launch of the contract so that users can see the code and verify that it compiles to the bytecode that is on-chain.
One issue related to using smart contracts on a public blockchain is that bugs, including security holes, are visible to all but cannot be fixed quickly. One example of this is the 2016 attack on The DAO, which could not be quickly stopped or reversed.
ERC-20 tokens
The ERC-20 (Ethereum Request-for-Comments #20) Token Standard allows for fungible
In economics and law, fungibility is the property of something whose individual units are considered fundamentally interchangeable with each other.
For example, the fungibility of money means that a $100 bill (note) is considered entirely equ ...
tokens on the Ethereum blockchain
The blockchain is a distributed ledger with growing lists of Record (computer science), records (''blocks'') that are securely linked together via Cryptographic hash function, cryptographic hashes. Each block contains a cryptographic hash of th ...
. The standard, proposed by Fabian Vogelsteller in November 2015, implements an API
An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...
for tokens within smart contract
A smart contract is a computer program or a Transaction Protocol Data Unit, transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. The objective ...
s. The standard provides functions that include the transfer of tokens from one account to another, getting the current token balance of an account, and getting the total supply of the token available on the network. Smart contracts that correctly implement ERC-20 processes are called ERC-20 Token Contracts, and they keep track of created tokens on Ethereum. Numerous cryptocurrencies have launched as ERC-20 tokens and have been distributed through initial coin offerings
In a written or published work, an initial is a letter at the beginning of a word, a chapter, or a paragraph that is larger than the rest of the text. The word is ultimately derived from the Latin ''initiālis'', which means ''of the beginning ...
.
Non-fungible tokens (NFTs)
Ethereum also allows for the creation of unique and indivisible tokens, called non-fungible token
A non-fungible token (NFT) is a unique digital identifier that is recorded on a blockchain and is used to certify ownership and authenticity. It cannot be copied, substituted, or subdivided. The ownership of an NFT is recorded in the blockchai ...
s (NFTs). Since tokens of this type are unique, they have been used to represent such things as collectibles, digital art, sports memorabilia, virtual real estate, and items within games. ERC-721 is the first official NFT standard for Ethereum and was followed up by ERC-1155 which introduced semi-fungibility, both are widely used, though some fully fungible tokens using ERC-20 have been used for NFTs such as ''CryptoPunks
''CryptoPunks'' is a non-fungible token (NFT) collection on the Ethereum blockchain. The project was launched in June 2017 by the Larva Labs studio, a two-person team consisting of Canadian software developers Matt Hall and John Watkinson. The ex ...
''.
The first NFT project, Etheria, a 3D map of tradable and customizable hexagonal tiles, was deployed to the network in October 2015 and demonstrated live at DEVCON1 in November of that year. In 2021, Christie's
Christie's is a British auction house founded in 1766 by James Christie (auctioneer), James Christie. Its main premises are on King Street, St James's in London, and it has additional salerooms in New York, Paris, Hong Kong, Milan, Geneva, Shan ...
sold a digital image with an NFT by Beeple for , making him the third-most-valuable living artist in terms of auction
An auction is usually a process of Trade, buying and selling Good (economics), goods or Service (economics), services by offering them up for Bidding, bids, taking bids, and then selling the item to the highest bidder or buying the item from th ...
prices at the time, although observers have noted that both the buyer and seller had a vested interest in driving demand for the artist's work.
Decentralized finance
Decentralized finance (DeFi) offers financial instrument
Financial instruments are monetary contracts between parties. They can be created, traded, modified and settled. They can be cash (currency), evidence of an ownership, interest in an entity or a contractual right to receive or deliver in the form ...
s in a decentralized architecture, outside of companies' and governments' control, such as money market funds which let users earn interest. DeFi applications are typically accessed through a Web3
Web3 (also known as Web 3.0) is an idea for a new iteration of the World Wide Web which incorporates concepts such as decentralization, blockchain technologies, and token-based economics. This is distinct from Tim Berners-Lee's concept of th ...
-enabled browser extension or application, such as MetaMask, which allows users to directly interact with the Ethereum blockchain through a website. Many of these DApps can connect and work together to create complex financial services.
Examples of DeFi platforms include MakerDAO. Uniswap
Uniswap is a Decentralization, decentralized cryptocurrency exchange that uses a set of automated smart contracts to create liquidity pools for the execution of trades. It is an open source project and falls into the category of a DeFi product ( ...
, a decentralized exchange for tokens on Ethereum grew from in liquidity to in 2020. As of October 2020, over was invested in various DeFi protocols. Additionally, through a process called "wrapping", certain DeFi protocols allow synthetic versions of various assets (such as bitcoin, gold, and oil) to be tradeable on Ethereum and also compatible with all of Ethereum's major wallets and applications.
Enterprise software
Ethereum-based software and networks, independent from the public Ethereum chain, have been tested by enterprise software
Enterprise software, also known as enterprise application software (EAS), is computer software used to satisfy the needs of an organization rather than its individual users. Enterprise software is an integral part of a computer-based information ...
companies. Interested parties have included Microsoft
Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...
, IBM
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
, JPMorgan Chase
JPMorgan Chase & Co. (stylized as JPMorganChase) is an American multinational financial services, finance corporation headquartered in New York City and incorporated in Delaware. It is List of largest banks in the United States, the largest ba ...
, Deloitte
Deloitte is a multinational professional services network based in London, United Kingdom. It is the largest professional services network in the world by revenue and number of employees, and is one of the Big Four accounting firms, along wi ...
, R3, and Innovate UK
Innovate UK is the United Kingdom's innovation agency, which provides money and support to organisations to make new products and services. It is a non-departmental public body operating at arm's length from the Government as part of the UK Res ...
(cross-border payments prototype). Barclays
Barclays PLC (, occasionally ) is a British multinational universal bank, headquartered in London, England. Barclays operates as two divisions, Barclays UK and Barclays International, supported by a service company, Barclays Execution Services ...
, UBS
UBS Group AG (stylized simply as UBS) is a multinational investment bank and financial services firm founded and based in Switzerland, with headquarters in both Zurich and Basel. It holds a strong foothold in all major financial centres as the ...
, Credit Suisse
Credit Suisse Group AG (, ) was a global Investment banking, investment bank and financial services firm founded and based in Switzerland. According to UBS, eventually Credit Suisse was to be fully integrated into UBS. While the integration ...
, Amazon
Amazon most often refers to:
* Amazon River, in South America
* Amazon rainforest, a rainforest covering most of the Amazon basin
* Amazon (company), an American multinational technology company
* Amazons, a tribe of female warriors in Greek myth ...
, Visa, and other companies have also experimented with Ethereum.
Permissioned ledgers
Ethereum-based permissioned blockchain variants are used and being investigated for various projects:
* In 2017, JPMorgan Chase
JPMorgan Chase & Co. (stylized as JPMorganChase) is an American multinational financial services, finance corporation headquartered in New York City and incorporated in Delaware. It is List of largest banks in the United States, the largest ba ...
proposed developing JPM Coin on a permissioned-variant of Ethereum blockchain dubbed "Quorum". It is "designed to toe the line between private and public in the realm of shuffling derivatives and payments. The idea is to satisfy regulators who need seamless access to financial goings-on while protecting the privacy of parties that don't wish to reveal their identities nor the details of their transactions to the general public."
Performance
, the maximum theoretical throughput for Ethereum is 142 TPS (given its current 36M gas limit, 12s blocks, and 21k gas cost for ETH transfers). Due to large smart contract and batch transaction using more gas in each block, the average transaction throughput is much less. , the Ethereum averaged about 25 transactions per second; this did not change after the move to proof-of-stake. In comparison, the Visa payment platform processes 45,000 payments per second. This has led some to question the scalability of Ethereum.
Ethereum's blockchain uses a Merkle–Patricia Tree to store account state in each block. The trie allows for storage savings, set membership proofs (called "Merkle proofs"), and light client synchronization. The network has faced congestion problems, such as in 2017 in relation to '' CryptoKitties''.
Legal Status and Regulation
The legal status of Ether (ETH), Ethereum's native token, remains subject to uncertainty and varies substantially from one jurisdiction to another.
In the United States, regulatory authorities have increasingly signaled that Ether should be treated as a commodity under the jurisdiction of the Commodity Futures Trading Commission
The Commodity Futures Trading Commission (CFTC) is an Independent agencies of the United States government, independent agency of the US government created in 1974 that regulates the U.S. derivatives markets, which includes futures contract, fut ...
(CFTC). The CFTC has repeatedly asserted its regulatory authority over Ethereum, with former CFTC Chairman Heath Tarbert stating in 2019 that "ETH is a commodity" and subsequent leadership maintaining this position. This classification is largely based on the decentralized nature of the Ethereum network, distinguishing it from securities that represent investments in a common enterprise.
From a private law perspective, many jurisdictions have recognized Ether as a form of intangible personal property that can be owned, transferred, and used as collateral, similar to other forms of personal property. In the United States specifically, the 2022 Amendments to the Uniform Commercial Code (UCC) introduced "controllable electronic records" (CERs) as a new category of personal property that includes digital assets like Ether. Under UCC Article 12, ETH is classified as a CER, which provides a comprehensive framework for its commercial circulation.
Notes
References
External links
*
{{authority control
2015 software
Blockchains
Cross-platform software
Cryptocurrency projects
Currencies introduced in 2015
*
Bytecodes