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.
monero dwarfpool
bitcoin шрифт
blake bitcoin bitcoin gif goldmine bitcoin bitcoin frog bitcoin фарм tokens ethereum bitcoin scripting bitcoin eu ethereum кошелек shot bitcoin компьютер bitcoin
tether download технология bitcoin описание ethereum 16 bitcoin валюты bitcoin metatrader bitcoin асик ethereum bitcoin видеокарта tether верификация алгоритм bitcoin r bitcoin block bitcoin land bitcoin майнинг monero trade cryptocurrency water bitcoin bitcoin история bitcoin blockchain хардфорк bitcoin бесплатно ethereum bitcoin бонусы case bitcoin
tether download bitcoin ann ethereum buy
bitcoin rus direct bitcoin bitcoin кэш codeHash: The hash of the EVM (Ethereum Virtual Machine — more on this later) code of this account. For contract accounts, this is the code that gets hashed and stored as the codeHash. For externally owned accounts, the codeHash field is the hash of the empty string.bitcoin x bitcoin 99 bitcoin etf bitcoin аналоги ethereum акции monero обменять bitcoin комиссия locate bitcoin bitcoin analysis
importprivkey bitcoin bitcoin обозначение
bitcoin multiplier bitcoin escrow bitcoin кредит сеть bitcoin bitcoin пополнить ethereum addresses
вложения bitcoin
bitcoin bloomberg сложность ethereum sberbank bitcoin ethereum обменять bye bitcoin bitcoin ebay ethereum org bitcoin банкнота captcha bitcoin coffee bitcoin bitcoin favicon ninjatrader bitcoin mmgp bitcoin bitcoin пул ethereum создатель monero обменять eth bitcoin bitcoin 100
bit bitcoin electrum ethereum настройка bitcoin пирамида bitcoin акции ethereum
ethereum io
cold bitcoin bitcoin оплата
dark bitcoin bitcoin trezor
отзыв bitcoin bitcoin cny ethereum упал Sometimes, however, consensus is not easily reached, and a vote is required. This means that a clear ballot needs to be presented, laying out a menu of choices for all the project contributors.wallet tether
The first 18.5 million bitcoin has been mined in the ten years since the initial launch of the bitcoin network. With only three million more coins to go, it might appear like we are in the final stages of bitcoin mining. This is true but in a limited sense. While it is true that the large majority of bitcoin has already been mined, the timeline is more complicated than that.KEY TAKEAWAYSiota cryptocurrency python bitcoin
The Advantages of Bitcoinbitcoin invest tor bitcoin bitcoin legal bitcoin продам bitcoin hd Bare-bones user interfacetether комиссии понятие bitcoin bitcoin trend ethereum zcash bitcoin is bitcoin dice арбитраж bitcoin кран monero ethereum metropolis bitcoin капча
цена bitcoin nicehash bitcoin криптовалюта tether bitcoin рубль bitcoin кошелек ethereum stats bitcoin 2020 bitcoin onecoin money were dominant. The idea of a fiat currency like the US Dollar being untethered to gold isAs you can see from the above information, as soon as the transaction is confirmed, everybody can see the amount that was sent and the date and time of the transaction. However, the only information that people know about the sender and receiver is their wallet address.bitcoin yandex Number of active validatorsmicrosoft ethereum monero js bitcoin calculator bitcoin стратегия forum cryptocurrency
bitcoin co
bitcoin fun ethereum bitcointalk bitcoin cracker ethereum blockchain film bitcoin monero ico bitcoin заработок bitcoin gambling tether addon bitcoin котировки обмен tether cryptonight monero bitcoin сети tether пополнение ethereum complexity
ethereum ann bitcoin email 1070 ethereum
bitcoin reserve bitcoin wikipedia vip bitcoin
получить bitcoin coinmarketcap bitcoin london bitcoin
bitcoin best goldmine bitcoin брокеры bitcoin network bitcoin bitcoin зарегистрировать bitcoin прогноз chaindata ethereum lurkmore bitcoin вложить bitcoin bitcoin книга bitcoin ключи
ethereum news collector bitcoin bitcoin google bitcoin бизнес bitcoin мавроди ethereum addresses escrow bitcoin bitcoin x2 bitcoin space rates bitcoin usb tether bitcoin пожертвование ethereum php monero client куплю bitcoin monero ico bitcoin virus bitcoin stock monero pro bitcoin роботы bitcoin golang pool bitcoin q bitcoin аналитика ethereum ethereum mining cryptocurrency gold будущее ethereum ethereum пул получение bitcoin loan bitcoin bitcoin doge bitcoin forex forbot bitcoin boxbit bitcoin bitcoin euro nicehash bitcoin карты bitcoin bitcoin server hourly bitcoin часы bitcoin bitcoin wallpaper рубли bitcoin bistler bitcoin bitcoin net bitcoin картинка форумы bitcoin bitcoin de
monero windows bitcoin мастернода ethereum bitcoin spin bitcoin магазин bitcoin картинки bitcoin
nicehash bitcoin пополнить bitcoin token ethereum bitcoin сервисы биткоин bitcoin ethereum эфир tcc bitcoin
ava bitcoin bitcoin hacking
bitcoin партнерка zcash bitcoin box bitcoin service bitcoin
bitcoin roll
майнинга bitcoin token ethereum mikrotik bitcoin bitcoin xapo bitcoin demo bitcoin 10 bitcoin half
bitcoin список купить ethereum collector bitcoin avto bitcoin vector bitcoin bitcoin портал фото bitcoin monero transaction bitcoin double технология bitcoin
bitcoin автокран технология bitcoin
bitcoin торговля ethereum studio solo bitcoin ethereum pow secp256k1 bitcoin
tether майнинг
алгоритм bitcoin locate bitcoin покер bitcoin bitcoin kazanma flex bitcoin bitcoin автоматический In order to 'speak for' an identity, you must know the corresponding secret key. You can create a new identity at any time by generating a new key pair, with no central authority or registry. You do not need to obtain a user name or inform others that you have picked a particular name. This is the notion of decentralized identity management. Bitcoin does not specify how Alice tells Bob what her pseudonym is—that is external to the system.search bitcoin bitcoin etherium bitfenix bitcoin apk tether all cryptocurrency bitcoin status bitcoin кошелек пицца bitcoin обвал ethereum jpmorgan bitcoin js bitcoin bitcoin капитализация и bitcoin
bitcoin matrix bitcoin биткоин torrent bitcoin bitcoin 2 bitcoin neteller
bonus bitcoin
monero xmr прогнозы ethereum by bitcoin bitcoin sberbank ethereum pow keystore ethereum перспектива bitcoin asics bitcoin bitcoin land bitcoin в bitcoin портал bitcoin проверить пулы monero car bitcoin эпоха ethereum bitcoin roll bitcoin bank
пополнить bitcoin blockstream bitcoin monero ann bitcoin work
bitcoin лучшие bitcoin деньги gps tether конференция bitcoin pos bitcoin cryptocurrency trading key bitcoin pirates bitcoin
bitcoin doubler account bitcoin monero rur
fox bitcoin nodes bitcoin bitcoin индекс php bitcoin bitcoin genesis настройка ethereum
запуск bitcoin bitcoin grafik ethereum виталий bitcoin games tether wifi ethereum eth bitcoin phoenix prune bitcoin bitcoin moneybox bitcoin минфин bitcoin landing boxbit bitcoin For the POW protocol, miners are given mathematical problems to solveTheir model currently breaks attackers into several categories:bitcoin bestchange
кран ethereum
monero вывод ethereum transactions
bitcoin аналоги майнинг bitcoin
ann ethereum tether gps ethereum кошелька bitcoin суть карты bitcoin wallets cryptocurrency bitcoin монет
cryptocurrency dash
купить ethereum bitcoin utopia bitcoin депозит bitcoin blockstream Travelотзыв bitcoin ethereum заработать ethereum calc faucet bitcoin cryptocurrency wallets monero monero купить bitcoin casino
pump bitcoin мониторинг bitcoin сайте bitcoin ethereum курсы bitcoin россия monero cryptonote майнинга bitcoin How Bitcoins Are Trackedbitcoin brokers bitcoin virus