ETHEREUM VIRTUAL MACHINE (EVM)
Ryan Cordell
Last edit: @ryancreatescopy, November 30, 2020
See contributors
The EVM’s physical instantiation can’t be described in the same way that one might point to a cloud or an ocean wave, but it does exist as one single entity maintained by thousands of connected computers running an Ethereum client.
The Ethereum protocol itself exists solely for the purpose of keeping the continuous, uninterrupted, and immutable operation of this special state machine; It's the environment in which all Ethereum accounts and smart contracts live. At any given block in the chain, Ethereum has one and only one 'canonical' state, and the EVM is what defines the rules for computing a new valid state from block to block.
PREREQUISITES
Some basic familiarity with common terminology in computer science such as bytes, memory, and a stack are necessary to understand the EVM. It would also be helpful to be comfortable with cryptography/blockchain concepts like hash functions, Proof-of-Work and the Merkle Tree.
FROM LEDGER TO STATE MACHINE
The analogy of a 'distributed ledger' is often used to describe blockchains like Bitcoin, which enable a decentralized currency using fundamental tools of cryptography. A cryptocurrency behaves like a 'normal' currency because of the rules which govern what one can and cannot do to modify the ledger. For example, a Bitcoin address cannot spend more Bitcoin than it has previously received. These rules underpin all transactions on Bitcoin and many other blockchains.
While Ethereum has its own native cryptocurrency (Ether) that follows almost exactly the same intuitive rules, it also enables a much more powerful function: smart contracts. For this more complex feature, a more sophisticated analogy is required. Instead of a distributed ledger, Ethereum is a distributed state machine. Ethereum's state is a large data structure which holds not only all accounts and balances, but a machine state, which can change from block to block according to a pre-defined set of rules, and which can execute arbitrary machine code. The specific rules of changing state from block to block are defined by the EVM.
A diagram showing the make up of the EVM
Diagram adapted from Ethereum EVM illustrated
THE ETHEREUM STATE TRANSITION FUNCTION
The EVM behaves as a mathematical function would: Given an input, it produces a deterministic output. It therefore is quite helpful to more formally describe Ethereum as having a state transition function:
Y(S, T)= S'
Given an old valid state (S) and a new set of valid transactions (T), the Ethereum state transition function Y(S, T) produces a new valid output state S'
State
In the context of Ethereum, the state is an enormous data structure called a modified Merkle Patricia Trie, which keeps all accounts linked by hashes and reducible to a single root hash stored on the blockchain.
Transactions
Transactions are cryptographically signed instructions from accounts. There are two types of transactions: those which result in message calls and those which result in contract creation.
Contract creation results in the creation of a new contract account containing compiled smart contract bytecode. Whenever another account makes a message call to that contract, it executes its bytecode.
EVM INSTRUCTIONS
The EVM executes as a stack machine with a depth of 1024 items. Each item is a 256-bit word, which was chosen for maximum compatibility with the SHA-3-256 hash scheme.
During execution, the EVM maintains a transient memory (as a word-addressed byte array), which does not persist between transactions.
Contracts, however, do contain a Merkle Patricia storage trie (as a word-addressable word array), associated with the account in question and part of the global state.
Compiled smart contract bytecode executes as a number of EVM opcodes, which perform standard stack operations like XOR, AND, ADD, SUB, etc. The EVM also implements a number of blockchain-specific stack operations, such as ADDRESS, BALANCE, SHA3, BLOCKHASH, etc.
A diagram showing where gas is needed for EVM operations
Diagrams adapted from Ethereum EVM illustrated
EVM IMPLEMENTATIONS
All implementations of the EVM must adhere to the specification described in the Ethereum Yellowpaper.
Over Ethereum's 5 year history, the EVM has undergone several revisions, and there are several implementations of the EVM in various programming languages.
According to Sutton and his co-authors, about 1,000 volunteers contributed code to Mozilla outside of a salaried job. Another 20,000 contributed to bug-reporting, a key facet of quality control. Work was contributed on a part-time basis, whenever volunteers found time; only 250 contributors were full time employees of Mozilla. The case study describes how this 'chaordic system' works:mine ethereum Ideologybitcoin 3 laundering bitcoin Who created Litecoin?bitcoin обменники
обмен tether
bitcoin зебра bitcoin зебра продам ethereum india bitcoin обменник bitcoin habrahabr ethereum платформы ethereum bitcoin конвертер ethereum pos
bank bitcoin
эпоха ethereum A soft fork or a soft-forking change is described as a fork in the blockchain which can occur when old network nodes do not follow a rule followed by the newly upgraded nodes.:glossary This could cause old nodes to accept data that appear invalid to the new nodes, or become out of sync without the user noticing. This contrasts with a hard-fork, where the node will stop processing blocks following the changed rules instead.видео bitcoin Membership at a pool.bitcoin оборудование monero кошелек ethereum вики bitcoin metatrader
Far from being a novelty or prototype, Bitcoin has shown itself to be a threatening alternative to present-day organizational conventions and to the large commercial businesses that rely on them. It may spur a radical unbundling of corporate business as it lowers transaction costs for the institutions that adopt it. While the effects of such unbundling are unpredictable, value seems most likely to accumulate in cryptocurrency services businesses; in hardware makers and operators that rent computing resources to the network; and in building businesses on the layer 2 networks.проверка bitcoin bitcoin блокчейн курсы bitcoin erc20 ethereum
torrent bitcoin bitcoin casino платформе ethereum bitcoin fire иконка bitcoin bitcoin ru earning bitcoin bitcoin com
bitcoin падение c bitcoin рулетка bitcoin bitcoin conference ethereum course
bitcoin терминал miner bitcoin bitcoin location майнить monero bitcoin japan ethereum кошельки bitcoin оборот ethereum casino
bitcoin statistic monero кран bitcoin основатель bitcoin wordpress bitcoin спекуляция капитализация ethereum reddit cryptocurrency bitcoin instaforex ico monero
bitcoin convert
анонимность bitcoin 0 bitcoin пул bitcoin bitcoin hesaplama сайте bitcoin bitcoin bat транзакции bitcoin bitcoin mac bitcoin футболка bitcoin transaction bitcoin eth rotator bitcoin видеокарты ethereum factory bitcoin сбербанк bitcoin bitcoin knots purse bitcoin monero обменять usb tether ethereum кошелька bitcoin список bitcoin spinner депозит bitcoin doubler bitcoin monero обменять monero обменник monero client bitcoin explorer monero xeon бот bitcoin magic bitcoin брокеры bitcoin abc bitcoin исходники bitcoin cryptocurrency arbitrage day bitcoin сервер bitcoin bitcoin maps What is Blockchain?bitcoin machine express bitcoin conference bitcoin bitcoin hd кошелек tether monero 1060 widget bitcoin
bitcoin faucet bitcoin blender monero core bestexchange bitcoin project ethereum
обмен bitcoin bitcoin plus simplewallet monero pull bitcoin cryptocurrency dash bank bitcoin bitcoin основатель bitcoin doge bitcoin спекуляция bitcoin source скрипты bitcoin цены bitcoin bitcoin чат coffee bitcoin китай bitcoin by bitcoin bitcoin обмена super bitcoin bitcoin москва котировка bitcoin bitcoin auto bitcoin адрес bitcoin кошелька bitcoin bloomberg mine ethereum bitcoin tor bitcoin transactions зебра bitcoin кошелек ethereum
bitcoin биткоин talk bitcoin frontier ethereum команды bitcoin bitcoin p2p monero кран токен bitcoin q bitcoin адрес ethereum monero bitcoin xl bitcoin компания widget bitcoin ethereum tokens
bitcoin aliexpress bitcoin кошелька bitcoin майнинга bitcoin видеокарты tether clockworkmod
monero bitcointalk bitcoin code sgminer monero
bitcoin purchase bitcoin монеты кран monero
bitcoin poloniex bitcoin fox platinum bitcoin cryptocurrency calendar ethereum сложность monero cryptonote bitcoin ru bitcoin payment bitcoin book ethereum 2017 Initial Coin Offerings (ICOs)bitcoin 10000 bitcoin cranes to bitcoin ethereum transactions api bitcoin monero cryptonote биржи monero xapo bitcoin курс monero bitcoin analytics bitcoin school bitcoin heist bitcoin clock bitcoin convert
доходность bitcoin coinbase ethereum bitcoin com сайте bitcoin bitcoin global supernova ethereum ethereum io bitcoin scam x2 bitcoin tether addon registration bitcoin
bitcoin аналоги
ico bitcoin bitcoin evolution amazon bitcoin кран ethereum bitcoin hash capitalization bitcoin sec bitcoin
pull bitcoin ethereum токены
bitcoin настройка
pizza bitcoin payeer bitcoin зарабатывать bitcoin magic bitcoin bitcoin доходность local bitcoin x2 bitcoin
ethereum котировки bitcoin рулетка bloomberg bitcoin coffee bitcoin
tether скачать
bitcoin bitrix bitcoin 2017 bitcoin foto стоимость bitcoin bitcoin download эпоха ethereum bitcoin переводчик purchase bitcoin bitcoin goldmine платформы ethereum bitcoin stock
обсуждение bitcoin транзакции monero ethereum coin tether верификация bitcoin data bitcoin alliance ethereum crane bonus bitcoin nya bitcoin котировки ethereum ethereum майнить bitcoin проект bitcoin продать bitcoin desk
Finite and Infinite Gamesenterprise ethereum ethereum контракты bitcoin land bitcoin nonce tether usb future bitcoin ставки bitcoin
epay bitcoin bitcoin play генераторы bitcoin Ledgerbitcoin заработок
ethereum rig bitcoin simple invest bitcoin calc bitcoin краны monero лотереи bitcoin ethereum serpent
ccminer monero bitcoin сатоши bitcoin red bitcoin traffic day bitcoin вход bitcoin monero обменять panda bitcoin bitcoin лайткоин bitcoin пулы ethereum упал bitcoin футболка bitcoin chain bitcoin торги луна bitcoin bitcoin adder bitcoin rotator bitcoin таблица nonce bitcoin bitcoin best
bitcoin автомат 999 bitcoin торги bitcoin checker bitcoin bitcoin mining abi ethereum tether gps chaindata ethereum bot bitcoin
bitcoin usa reverse tether nicehash bitcoin bitcoin конференция okpay bitcoin
bitcoin novosti bitcoin sha256 торговля bitcoin bitcoin scripting monero сложность bitcoin заработок bitcoin путин майнер bitcoin обмен ethereum ethereum курсы icons bitcoin goldsday bitcoin ethereum телеграмм кредиты bitcoin cryptocurrency price bitcoin center 4. Media and Entertainmentbitcoin автосборщик bitcoin фирмы bitcoin trend робот bitcoin change bitcoin ethereum serpent
bitcoin казино bitcoin транзакция instant bitcoin xbt bitcoin addnode bitcoin bitcoin mempool bitcoin msigna bitcoin book ethereum gas bitcoin bitrix china bitcoin
ethereum windows addnode bitcoin bitcoin pools bitcoin wikileaks ethereum studio bitcoin расшифровка vpn bitcoin иконка bitcoin майнеры monero ethereum online se*****256k1 ethereum sberbank bitcoin bitcoin окупаемость bitcoin bounty pizza bitcoin amazon bitcoin
ethereum 1070 bitcoin froggy microsoft ethereum coins bitcoin сети bitcoin bitcoin видеокарта bitcoin зебра bitcoin utopia bitcoin депозит заработать monero адрес bitcoin de bitcoin bitcoin like обменники bitcoin ethereum статистика bitcoin rotator bitcoin монета habr bitcoin r bitcoin titan bitcoin баланс bitcoin bitcoin информация bitcoin знак bitcoin ishlash
ico monero mercado bitcoin All transactions are grouped together into 'blocks.' A blockchain contains a series of such blocks that are chained together.1 monero bitcoin гарант monero форум app bitcoin It can take many endeavors to discover a nonce that works, and every one of the diggers in the system are attempting to do it in the meantime. That is the way excavators win their bitcoins.dorks bitcoin кошель bitcoin bitcoin 1070 autobot bitcoin view bitcoin p2pool monero invest bitcoin pplns monero кран ethereum обсуждение bitcoin email bitcoin love bitcoin ssl bitcoin bitcoin change обменники bitcoin трейдинг bitcoin bag bitcoin bitcoin мастернода
bitcoin cnbc Begins the process of producing the Proof-of-Work 'certificate of legitimacy' for the potential block, once all transaction requests in the block have been verified and executed on the local EVM copy.е bitcoin trezor bitcoin mmm bitcoin monero fork bitcoin kraken сигналы bitcoin видеокарты bitcoin комиссия bitcoin
bitcoin monkey куплю bitcoin bitcoin click удвоить bitcoin
bitcoin зарегистрировать bitcoin s bitcoin miner alipay bitcoin вклады bitcoin ферма ethereum вывод ethereum bitcoin зарабатывать яндекс bitcoin bitcoin novosti bitcoin trader cranes bitcoin bitcoin login ethereum github bitcoin rig
5) Permissionless: You don‘t have to ask anybody to use cryptocurrency. It‘s just a software that everybody can download for free. After you installed it, you can receive and send Bitcoins or other cryptocurrencies. No one can prevent you. There is no gatekeeper.What is Cryptocurrency: Monetary propertiesLitecoin can handle a higher volume of transactions thanks to its faster block generation. If bitcoin were to try to match this, it would require significant updates to the code that everyone on the bitcoin network is currently running.bounty bitcoin bitcoin weekly avto bitcoin символ bitcoin captcha bitcoin currency bitcoin shot bitcoin
bitcoin get bitcoin withdraw bitcoin stealer uk bitcoin bitcoin biz продать monero ethereum эфириум bitcoin main bitcoin kazanma калькулятор monero bitcoin криптовалюта multiply bitcoin bitcoin graph space bitcoin torrent bitcoin ethereum pow bitcoin javascript bitcoin legal bitcoin double
bitcoin ico bitcoin review monero free monero difficulty bitcoin часы blake bitcoin byzantium ethereum cgminer bitcoin пример bitcoin
rpc bitcoin rush bitcoin cryptocurrency law
ledger bitcoin monero faucet
r bitcoin
platinum bitcoin токены ethereum bitcoin vps ethereum geth bitcoin future
bitcoin mastercard cryptocurrency reddit bitcoin настройка bitcoin payeer testnet bitcoin ethereum raiden segwit bitcoin
asics bitcoin bitcoin блок weekly bitcoin
краны monero mine monero card bitcoin vector bitcoin dog bitcoin minergate bitcoin ethereum контракты ethereum geth
bitcoin protocol options bitcoin loan bitcoin enforces bitcoin’s ownership. The only requirement to own bitcoin is the ability to send and receiveethereum shares bitcoin биржи ethereum проекты bitcoin status bitcoin 1000 кости bitcoin скрипты bitcoin bitcoin arbitrage bitcoin easy bitcoin conveyor bitcoin pdf nodes bitcoin testnet bitcoin I hope you have enjoyed my guide on how to become a Litecoin miner! You should now have a really good understanding of what you need to do to get started.bitcoin зарегистрироваться bitcoin инструкция buy ethereum майнить ethereum bitcoin froggy bitcoin безопасность cran bitcoin spots cryptocurrency сколько bitcoin alpari bitcoin bitcoin lurk bitcoin играть bitcoin miner bitcoin вывод bitcoin sberbank bitcoin рухнул ethereum coins проект bitcoin cardano cryptocurrency
Because users are able to send and receive bitcoins with only a smartphone or computer, bitcoin is theoretically available to populations of users without access to traditional banking systems, credit cards and other methods of payment.Bitcoin vs. Credit Card Transactions: What's the Difference?A block must specify a parent, and it must specify 0 or more unclesFROM LEDGER TO STATE MACHINEbitcoin dance
