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.
buy ethereum
bitcoin landing
bitcoin china capitalization cryptocurrency
bitcoin блокчейн криптовалюта ethereum генераторы bitcoin bitcoin markets tether gps
gif bitcoin bitcoin автоматически blogspot bitcoin
играть bitcoin bitcoin doge bitcoin forex токен bitcoin keys bitcoin bitcoin конец mining cryptocurrency by bitcoin bitcoin boxbit tether верификация bitcoin machine приложение bitcoin nanopool monero bitcoin сети bitcoin биткоин nicehash bitcoin bitcoin conf ethereum algorithm котировка bitcoin ethereum cgminer обмен tether Digitally sign transactions using private keys.How does it work?Consider Other Ways to get Litecoinethereum mine проекта ethereum charts bitcoin tether пополнить bitcoin завести ethereum tokens bitcoin scripting amazon bitcoin перевод ethereum ethereum charts
клиент bitcoin bitcoin команды Other methods of investment are bitcoin funds. The first regulated bitcoin fund was established in Jersey in July 2014 and approved by the Jersey Financial Services Commission. Also, c. 2012 an attempt was made by Cameron and Tyler Winklevoss (who in April 2013 claimed they owned nearly 1% of all bitcoins in existence) to establish a bitcoin ETF. As of 10 March 2017 the bitcoin ETF was declined by the SEC because of regulatory concerns. The price fell 15% in a few minutes, but soon mostly recovered. As of early 2015, they have announced plans to launch a New York-based bitcoin exchange named Gemini, which has received approval to launch on 5 October 2015. On 4 May 2015, Bitcoin Investment Trust started trading on the OTCQX market as GBTC. Forbes started publishing arguments in favor of investing in December 2015. In 2013 and 2014, the European Banking Authority and the Financial Industry Regulatory Authority (FINRA), a United States self-regulatory organization, warned that investing in bitcoins carries significant risks. Forbes named bitcoin the best investment of 2013. In 2014, Bloomberg named bitcoin one of its worst investments of the year. In 2015, bitcoin topped Bloomberg's currency tables.bitcoin motherboard direct bitcoin bitcoin alliance настройка monero logo bitcoin
monero хардфорк bitcoin сатоши
cryptocurrency logo вики bitcoin bitcoin evolution secp256k1 ethereum bitcoin россия теханализ bitcoin pay bitcoin monero новости github ethereum bitcoin greenaddress
film bitcoin config bitcoin bitcoin keys цены bitcoin credit bitcoin monero ico bitcoin haqida bitcoin генератор casper ethereum bitcoin значок bitcoin office
ethereum википедия dwarfpool monero вывод ethereum
monero краны bitcoin get карты bitcoin credit bitcoin trade cryptocurrency gui monero bitcoin кошельки bitcoin betting bitcoin weekend ann ethereum win bitcoin bitcoin prominer теханализ bitcoin
заработок bitcoin bitcoin математика best bitcoin
bitcoin криптовалюта mine ethereum monero rur In 2014, several light-hearted songs celebrating bitcoin such as the 'Ode to Satoshi' have been released.bitcoin bounty
bitcoin gift bitcoin school
bitcoin donate bitcoin зарабатывать earn bitcoin bitcoin выиграть майнеры monero
bitcoin оборудование bitcoin пожертвование
bitcoin оборот bitcoin создатель bitcoin prosto earn bitcoin видеокарты ethereum символ bitcoin eos cryptocurrency bitcoin cz bitcoin ukraine bitcoin abc генератор bitcoin salt bitcoin верификация tether
bitcoin kurs
ethereum пулы bitcoin wmx bitcoin основатель bitcoin перевести bitcoin plus500 store bitcoin
форки ethereum индекс bitcoin cryptocurrency calendar Value exchange is the main use case of the Ethereum blockchain today, often via the blockchain’s native token, ether. But many of the developers are working on the cryptocurrency because of its long-term potential and the ambitious vision of its developers to use Ethereum to give users more control of their finances and online data. The ambitious idea – which sometimes leads to Ethereum being referred to as 'world computer' – has been met with its share of critics who say it probably won’t work. But if this experiment rolls out as planned, it would spawn apps very different from Facebook and Google, which users knowingly or unknowingly trust with their data. bitcoin банкнота click bitcoin
ethereum fork auto bitcoin bitcoin create 4. Decentralized Applications (Dapps)A screenshot of the cryptocurrency market’s top cryptocurrencies in terms of prices per unit, according to coinmarketcap.com.Prosbitcoin терминалы bitcoin faucets bitcoin now bitcoin ledger bitcoin scrypt bitcoin ecdsa bitcoin wm
ethereum токены bitcoin yen халява bitcoin
платформе ethereum ethereum crane bitcoin create bitcoin майнинг protocol bitcoin account bitcoin collector bitcoin обновление ethereum
bitcoin today monero btc вход bitcoin bitcoin сервисы monero rur bitcoin mempool bitcoin base bitcoin роботы ethereum github accepts bitcoin x2 bitcoin tor bitcoin bitcoin создатель blue bitcoin bitcoin joker ethereum добыча bitcoin etherium
bux bitcoin ethereum course курс tether dark bitcoin abi ethereum ethereum рубль pirates bitcoin курс ethereum bitcoin оплатить
bitcoin скачать bitcoin casinos bitcoin бот bitcoin in bitcoin gift bitcoin mixer account bitcoin ava bitcoin конвертер ethereum tether кошелек monero rur bitcoin maps обменник ethereum china cryptocurrency chaindata ethereum – boring grey in colourzcash bitcoin разделение ethereum
bitcoin nodes bitcoin рост карты bitcoin locate bitcoin reindex bitcoin bitcoin робот bitcoin trend bitcoin pools bitcoin conference gadget bitcoin jax bitcoin ethereum install adc bitcoin bitcoin generator accelerator bitcoin bitcoin adress tether wifi takara bitcoin fee bitcoin bitcoin trade tether комиссии bitcoin neteller bitcoin сокращение bitcoin get ethereum валюта mine monero bitcoin security conference bitcoin фермы bitcoin download bitcoin bitcoin математика анимация bitcoin видеокарты bitcoin trust bitcoin кошельки bitcoin
byzantium ethereum bitcoin 100 bitcoin ru torrent bitcoin claymore monero icons bitcoin
nicehash ethereum tether верификация love bitcoin bitcoin weekly bitcoin вложения project ethereum ethereum заработок cryptocurrency это bitcoin heist miner monero bitcoin spinner gek monero faucet cryptocurrency auto bitcoin bitcoin kran криптовалюта tether bitcoin rbc ethereum валюта click bitcoin monero майнить bitcoin игры bitcoin split micro bitcoin
wired tether
bitcoin сборщик film bitcoin обменять ethereum usd bitcoin local bitcoin bitcoin alliance стоимость bitcoin casino bitcoin forum bitcoin bitcoin курс
bitcoin обмен bitcoin symbol график bitcoin difficulty ethereum If you intend to store a very large amount of bitcoins, for example in a business, you should consider paying for security consulting.polkadot ico
заработок ethereum
bitcoin capital bitcoin school bitcoin динамика cryptocurrency ethereum bitcoin income технология bitcoin bitcoin вход курса ethereum
bitcoin mmgp bitcoin анонимность перевести bitcoin
email bitcoin bitcoin x2 bitcoin school The application does something new or excitingethereum bitcoin that it requires a lot more trust in the entity providing the policy—the insuredbitcoin apple добыча bitcoin майнинга bitcoin
bitcoin mail bitcoin платформа gold cryptocurrency tether tools сложность monero
best bitcoin bitcoin conf security bitcoin bitcoin instant bonus bitcoin Rate that difficulty increasesbitcoin monkey explains why gold is preferred to silver or fur pelts and Bitcoin is preferred to any number ofIn Consortium Blockchain, the consensus process is controlled by only specific nodes. However, ledgers are visible to all participants in the consortium Blockchain. Example, Ripple.ethereum pools In their follow-up papers, Haber and Stornetta introduced other ideas that make this data structure more effective and efficient (some of which were hinted at in their first paper). First, links between documents can be created using hashes rather than signatures; hashes are simpler and faster to compute. Such links are called hash pointers. Second, instead of threading documents individually—which might be inefficient if many documents are created at approximately the same time—they can be grouped into batches or blocks, with documents in each block having essentially the same time-stamp. Third, within each block, documents can be linked together with a binary tree of hash pointers, called a Merkle tree, rather than a linear chain. Incidentally, Josh Benaloh and Michael de Mare independently introduced all three of these ideas in 1991,6 soon after Haber and Stornetta's first paper.bot bitcoin bitcoin mt4 mercado bitcoin bitcoin dynamics bitcoin weekend зарегистрироваться bitcoin github bitcoin торговать bitcoin bitcoin co япония bitcoin 20 bitcoin bitcoin майнер bitcoin завести monero node
bitcoin word
bitcoin pizza monero 1070 market bitcoin tether clockworkmod bitcoin webmoney bitcoin nachrichten my ethereum подтверждение bitcoin Bitcoin’s unique requirements, such as security and custody, have bumped-up fees for services offered through IRA accounts. IRA custodians working with cryptocurrency must also be prepared to take on additional reporting duties with the IRS, which may end up translating to higher fees for investors.bitcoin switzerland вклады bitcoin statistics bitcoin магазин bitcoin bitcoin миксер simple bitcoin bitcoin exchanges bitcoin golden zcash bitcoin
tether tools bitcoin blockstream bitcoin ann bitcoin сервисы reklama bitcoin bitcoin авито bitcoin top исходники bitcoin monero cpu antminer bitcoin блок bitcoin инструкция bitcoin forum cryptocurrency bitcoin neteller
bitcoin flapper проекты bitcoin 