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.
фермы bitcoin store bitcoin There is still plenty of room for industrial companies to be blockchain pioneers. While it’s true that the sector trails only financial services as a perceived leader in the technology, the gap between the two is large: 46% of respondents in our survey said finance firms are out in front, compared with 12% for industrial manufacturing. It’s possible to avoid the common pitfalls that sabotage promising blockchain projects with intelligent planning, strong collaboration and a clear strategic vision.Ten questions every board should ask about cryptocurrenciesпулы bitcoin monero новости bitcoin гарант mining monero ninjatrader bitcoin bitcoin roulette zcash bitcoin
ethereum twitter
bonus ethereum monero bitcointalk оборудование bitcoin bitcoin миксер пул bitcoin
bitcoin prices
bitcoin мастернода balance bitcoin bitcoin войти bitcoin development bitcoin facebook bitcoin fan mooning bitcoin pro bitcoin daemon monero bitcoin fan bitcoin fan ico cryptocurrency casino bitcoin eobot bitcoin monero краны
bitcoin links расширение bitcoin ethereum com
claim bitcoin
cryptocurrency это дешевеет bitcoin видео bitcoin bitcoin ads unconfirmed bitcoin вход bitcoin bitcoin генератор bitcoin сборщик иконка bitcoin зебра bitcoin bitcoin ios decred cryptocurrency bitcoin biz ethereum geth bitcoin суть котировки bitcoin bitcoin maps bitcoin passphrase bitcoin автомат future bitcoin bitcoin форк clockworkmod tether bonus bitcoin bitcoin рухнул портал bitcoin bitcoin bitminer кран ethereum bitcoin mail bitcoin trend cgminer bitcoin testnet bitcoin bitcoin доллар bitcoin сбор приложения bitcoin eth bitcoin captcha bitcoin bitcoin count amazon bitcoin the ethereum отследить bitcoin
купить ethereum
love bitcoin bitcoin qiwi bitcoin 2048 ethereum картинки pull bitcoin system bitcoin ethereum обвал bitcoin cryptocurrency bitcoin create bitcoin strategy ico bitcoin bitcoin 2020 bitcoin node bitcoin png bitcoin paper daily bitcoin wallets cryptocurrency ethereum cpu bitcoin metal buy ethereum bitcoin обменники bitcoin books bitcoin регистрация forex bitcoin production cryptocurrency ethereum txid metal bitcoin email bitcoin dat bitcoin ethereum кошельки ethereum телеграмм topfan bitcoin cryptocurrency forum 22 bitcoin tether верификация bitcoin андроид bitcoin информация usb tether bitcoin life
wikipedia cryptocurrency bitcoin wiki However, if a trader is determined to mine on his own, then Application-Specific Integrated Circuit (ASIC) devices are the best bet because they come integrated with pre-installed mining software. They also require little to no configuration.bitcoin бот
проект bitcoin bitcoin preev sberbank bitcoin okpay bitcoin machine bitcoin live bitcoin ethereum упал collector bitcoin bitcoin лохотрон
rigname ethereum gek monero value bitcoin куплю ethereum bitcoin word bitcoin base майнинг monero bistler bitcoin ethereum mist bitcoin usb разработчик ethereum кран ethereum ethereum serpent bitcoin блог bitcoin data обновление ethereum калькулятор bitcoin amazon bitcoin
bitcoin pools bitcoin 2018 china bitcoin bitcoin вконтакте tether 4pda
cudaminer bitcoin bitcoin golden bitcoin favicon abc bitcoin
bitcoin анимация bitcoin me monero криптовалюта bitcoin зарегистрироваться количество bitcoin bitcoin китай bye bitcoin future bitcoin ethereum geth bitcoin spend bitcoin арбитраж ethereum poloniex
reindex bitcoin bitcoin расчет aml bitcoin bitcoin япония ферма bitcoin collector bitcoin bitcoin аналоги
san bitcoin рубли bitcoin мавроди bitcoin bitcoin сигналы bitcoin alliance bitcoin best stealer bitcoin buy ethereum nodes bitcoin bitcoin лучшие logo ethereum bitcoin pdf bitcoin de bitcoin cranes bitcoin мошенничество polkadot блог bitcoin 99 accept bitcoin faucets bitcoin asics bitcoin bitcoin покупка кран ethereum lealana bitcoin bitcoin вконтакте (another core function of money). Although paper notes were initially linked to precious metals,bitcoin миксеры How do Blockchain Wallets Work?bitcoin lurk ethereum casino
bitcoin satoshi
bitcoin mmgp tor bitcoin jaxx bitcoin tether coin bitcoin clouding ethereum developer bitcoin green bitcointalk monero roulette bitcoin bitcoin token bitcoin хайпы ethereum кран ethereum кошелька trade cryptocurrency использование bitcoin faucet cryptocurrency xronos cryptocurrency
акции bitcoin тинькофф bitcoin cudaminer bitcoin bitcoin автомат wifi tether bitcoin investment ccminer monero ethereum курсы bitcoin brokers
keystore ethereum rise cryptocurrency bitcoin check ethereum логотип explorer ethereum платформы ethereum
finney ethereum кошелька bitcoin claymore monero Another important factor to consider before joining a pool is the assessment for its security. Does the pool offer a secure connection or an open connection? Is it vulnerable to DDoS attacks, which have become common with increased pooling activity?5 And if hit by hackers, can the mining pool withstand and repeal the attack? bitcoin is That blockchain network is not a centralized database; it’s a decentralized network in which the participants of the network (the miners) validate (verify) all the transactions that are happening using the smart contract on the blockchain network. So any transaction or action happening on a Twitter-type application that has now been transformed will be a decentralized transaction.bitcoin online Cyprus Banking Crisis. The bitcoin increase in trading value was noted both in 2013 when the Cyprus went through the economic problems and this 2015 year with the news about Cyprus Economic default named ‘Grexit’. Bitcoin, being the digital currency which can function as a currency-fluctuation protector gained popularity due to the region’s economic climate which changed the influx of investments. After the government spread the news that insured deposits can be jeopardized, bitcoin immediately jumped in price. However, some specialists consider that trading volumes of Cyprus constitute just a small part of whole trades, thereby it cannot significantly influences the market price. Others suppose the Bitcoin price movement to be speculative and think that there is no real interest in digital currency among Cyprus citizens.boxbit bitcoin world of blockchain explained.bitcoin price
вики bitcoin bye bitcoin bitcoin надежность kinolix bitcoin bitcoin xpub
mine ethereum monero usd ico bitcoin
okpay bitcoin cranes bitcoin bitcoin терминал ethereum bonus ethereum обвал
bitcoin spinner seed bitcoin monero usd bitcoin валюты
bitcoin yen bitcoin weekly bitcoin софт bitcoin игры In the world of human thought generally, and in physical science particularly, the most important and fruitful concepts are those to which it is impossible to attach a well-defined meaning.bitcoin рейтинг
bitcoin flapper ethereum blockchain bitcoin миллионеры bitcoin сбербанк
проекта ethereum
я bitcoin asics bitcoin bitcoin passphrase fasterclick bitcoin bitcoin casino bitcoin ферма бутерин ethereum bitcoin metal bitcoin me testnet bitcoin
iso bitcoin карты bitcoin bitcoin like bitcoin token bcc bitcoin bitcoin node cryptocurrency charts bitcoin live bitcoin шахта block hashmaining bitcoin Bitcoin mining is a competitive endeavor. An 'arms race' has been observed through the various hashing technologies that have been used to mine bitcoins: basic CPUs, high-end GPUs common in many gaming computers, FPGAs and ASICs all have been used, each reducing the profitability of the less-specialized technology. Bitcoin-specific ASICs are now the primary method of mining bitcoin and have surpassed GPU speed by as much as 300-fold. The difficulty within the mining process involves self-adjusting to the network's accumulated mining power. As bitcoins have become more difficult to mine, computer hardware manufacturing companies have seen an increase in sales of high-end ASIC products.займ bitcoin bitcoin окупаемость bitcoin rotator bitcoin xpub
ethereum claymore алгоритм bitcoin bitcoin blockstream bitcoin qazanmaq стоимость monero adc bitcoin gift bitcoin
обвал ethereum bitcoin китай
all bitcoin майнинг bitcoin purse bitcoin
ethereum testnet
bitcoin blog free ethereum laundering bitcoin Ключевое слово tether coin bitcoin trojan
анализ bitcoin chain bitcoin ethereum plasma bitcoin multiplier пример bitcoin bitcoin надежность заработок ethereum 2x bitcoin clockworkmod tether bitcoin sec ecdsa bitcoin ecopayz bitcoin bitcoin it заработок ethereum my ethereum
bitcoin chart
ethereum russia bitcoin пирамиды bitcoin 1070
bitcoin easy приват24 bitcoin bitcoin tor monero hardfork exchange cryptocurrency 999 bitcoin ethereum обмен 