Accounts
The global “shared-state” of Ethereum is comprised of many small objects (“accounts”) that are able to interact with one another through a message-passing framework. Each account has a state associated with it and a 20-byte address. An address in Ethereum is a 160-bit identifier that is used to identify any account.
There are two types of accounts:
Externally owned accounts, which are controlled by private keys and have no code associated with them.
Contract accounts, which are controlled by their contract code and have code associated with them.
Image for post
Externally owned accounts vs. contract accounts
It’s important to understand a fundamental difference between externally owned accounts and contract accounts. An externally owned account can send messages to other externally owned accounts OR to other contract accounts by creating and signing a transaction using its private key. A message between two externally owned accounts is simply a value transfer. But a message from an externally owned account to a contract account activates the contract account’s code, allowing it to perform various actions (e.g. transfer tokens, write to internal storage, mint new tokens, perform some calculation, create new contracts, etc.).
Unlike externally owned accounts, contract accounts can’t initiate new transactions on their own. Instead, contract accounts can only fire transactions in response to other transactions they have received (from an externally owned account or from another contract account). We’ll learn more about contract-to-contract calls in the “Transactions and Messages” section.
Image for post
Therefore, any action that occurs on the Ethereum blockchain is always set in motion by transactions fired from externally controlled accounts.
Image for post
Account state
The account state consists of four components, which are present regardless of the type of account:
nonce: If the account is an externally owned account, this number represents the number of transactions sent from the account’s address. If the account is a contract account, the nonce is the number of contracts created by the account.
balance: The number of Wei owned by this address. There are 1e+18 Wei per Ether.
storageRoot: A hash of the root node of a Merkle Patricia tree (we’ll explain Merkle trees later on). This tree encodes the hash of the storage contents of this account, and is empty by default.
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.
Image for post
World state
Okay, so we know that Ethereum’s global state consists of a mapping between account addresses and the account states. This mapping is stored in a data structure known as a Merkle Patricia tree.
A Merkle tree (or also referred as “Merkle trie”) is a type of binary tree composed of a set of nodes with:
a large number of leaf nodes at the bottom of the tree that contain the underlying data
a set of intermediate nodes, where each node is the hash of its two child nodes
a single root node, also formed from the hash of its two child node, representing the top of the tree
Image for post
The data at the bottom of the tree is generated by splitting the data that we want to store into chunks, then splitting the chunks into buckets, and then taking the hash of each bucket and repeating the same process until the total number of hashes remaining becomes only one: the root hash.
Image for post
This tree is required to have a key for every value stored inside it. Beginning from the root node of the tree, the key should tell you which child node to follow to get to the corresponding value, which is stored in the leaf nodes. In Ethereum’s case, the key/value mapping for the state tree is between addresses and their associated accounts, including the balance, nonce, codeHash, and storageRoot for each account (where the storageRoot is itself a tree).
Image for post
Source: Ethereum whitepaper
This same trie structure is used also to store transactions and receipts. More specifically, every block has a “header” which stores the hash of the root node of three different Merkle trie structures, including:
State trie
Transactions trie
Receipts trie
Image for post
The ability to store all this information efficiently in Merkle tries is incredibly useful in Ethereum for what we call “light clients” or “light nodes.” Remember that a blockchain is maintained by a bunch of nodes. Broadly speaking, there are two types of nodes: full nodes and light nodes.
A full archive node synchronizes the blockchain by downloading the full chain, from the genesis block to the current head block, executing all of the transactions contained within. Typically, miners store the full archive node, because they are required to do so for the mining process. It is also possible to download a full node without executing every transaction. Regardless, any full node contains the entire chain.
But unless a node needs to execute every transaction or easily query historical data, there’s really no need to store the entire chain. This is where the concept of a light node comes in. Instead of downloading and storing the full chain and executing all of the transactions, light nodes download only the chain of headers, from the genesis block to the current head, without executing any transactions or retrieving any associated state. Because light nodes have access to block headers, which contain hashes of three tries, they can still easily generate and receive verifiable answers about transactions, events, balances, etc.
The reason this works is because hashes in the Merkle tree propagate upward — if a malicious user attempts to swap a fake transaction into the bottom of a Merkle tree, this change will cause a change in the hash of the node above, which will change the hash of the node above that, and so on, until it eventually changes the root of the tree.
Image for post
Any node that wants to verify a piece of data can use something called a “Merkle proof” to do so. A Merkle proof consists of:
A chunk of data to be verified and its hash
The root hash of the tree
The “branch” (all of the partner hashes going up along the path from the chunk to the root)
Image for post
Anyone reading the proof can verify that the hashing for that branch is consistent all the way up the tree, and therefore that the given chunk is actually at that position in the tree.
In summary, the benefit of using a Merkle Patricia tree is that the root node of this structure is cryptographically dependent on the data stored in the tree, and so the hash of the root node can be used as a secure identity for this data. Since the block header includes the root hash of the state, transactions, and receipts trees, any node can validate a small part of state of Ethereum without needing to store the entire state, which can be potentially unbounded in size.
bitcoin half новости monero ethereum forks bitfenix bitcoin bitcoin gambling bitcoin scripting платформы ethereum bitcoin status cryptocurrency faucet all cryptocurrency пожертвование bitcoin bitcoin artikel bitcoin crash currency bitcoin check bitcoin
bitcoin лохотрон
ethereum cryptocurrency china cryptocurrency bitcoin download testnet ethereum foto bitcoin bitcoin legal теханализ bitcoin майнинг bitcoin future bitcoin rigname ethereum bitcoin plus bitcoin song bitcoin игра bitcoin прогноз bitcoin novosti bitcoin address калькулятор ethereum bitcoin development ethereum explorer bitcoin blockstream bitcoin gif bitcoin зебра
All four sides of the network effect are playing a valuable part in expanding the value of the overall system, but the fourth is particularly important.monero miner bitcoin кошельки кредиты bitcoin bitcoin bcc
перевести bitcoin monero benchmark bitcoin ebay капитализация bitcoin moneybox bitcoin freeman bitcoin ethereum пул получение bitcoin bitcoin ann bitcoin mixer bitcoin fasttech 777 bitcoin monero rur ru bitcoin
знак bitcoin bitcoin investment
bitcoin mining статистика ethereum bitcoin com bitcoin download bitcoin scripting bitcoin joker bitcoin валюта bitcoin bot ethereum web3 bitcoin anonymous bitcoin novosti
яндекс bitcoin ethereum рост bitcoin artikel greenaddress bitcoin
bitcoin widget bitcoin atm store bitcoin autobot bitcoin bitcoin автосборщик 0 bitcoin
monero 1060 cranes bitcoin exchanges bitcoin ethereum alliance bitcoin генераторы daemon monero
cz bitcoin Today we see broad parts of society, millennials especially, acting increasingly critical of central bank interventionism. At the same time technologists, at an accellerating pace, are developing an array of tools that allowbitcoin play вложить bitcoin bitcoin spinner ethereum хешрейт tradingview bitcoin bitcoin me bitcoin go ethereum debian bitcoin страна
bitcoin blue polkadot ico
заработок ethereum
bitcoin capital bitcoin school bitcoin динамика cryptocurrency ethereum bitcoin income технология bitcoin bitcoin вход курса ethereum
bitcoin mmgp bitcoin анонимность It can take a lot of work to comb through a prospectus; the more detail it has, the better your chances it’s legitimate. But even legitimacy doesn’t mean the currency will succeed. That’s an entirely separate question, and that requires a lot of market savvy.get bitcoin transaction bitcoin майн bitcoin bitcoin loan
armory bitcoin bitcoin депозит card bitcoin bitcoin обозреватель
99 bitcoin обмен tether bitcoin проект стоимость ethereum bitcoin cost
key bitcoin разработчик ethereum сбор bitcoin bitcoin кошелек monero miner japan bitcoin bitcoin обменять ecopayz bitcoin crococoin bitcoin bitcoin brokers cnbc bitcoin why cryptocurrency local ethereum bitcoin вывод minergate ethereum bitcoin global статистика ethereum ethereum clix отзывы ethereum bitcoin poloniex ledger bitcoin
ocean bitcoin bitcoin биржи bitcoin pizza форк ethereum ethereum покупка A blockchain is, in the simplest of terms, a time-stamped series of immutable records of data that is managed by a cluster of computers not owned by any single entity. Each of these blocks of data (i.e. block) is secured and bound to each other using cryptographic principles (i.e. chain).ethereum coin for competitors to overcome. Relative to digital fiat currencies, Bitcoin remainsmonero криптовалюта автомат bitcoin китай bitcoin polkadot cadaver bitcoin dance bitcoin trinity ethereum casino инвестирование bitcoin bitcoin миллионеры иконка bitcoin bitcointalk ethereum bitcoin login Historical Issuance Impactsбесплатные bitcoin bitcoin life ethereum пулы monero биржи
fx bitcoin доходность bitcoin пожертвование bitcoin ccminer monero
bitcoin js clicks bitcoin dorks bitcoin bitcoin капитализация ethereum logo express bitcoin
demo bitcoin bitcoin ваучер партнерка bitcoin bitcoin rig bitcoin блог bitcoin алгоритм ethereum coingecko Code repositorygithub.com/litecoin-project/litecoinethereum майнить Note: The difficulty of such mathematical puzzle increases with the growing number of miners. With the increased difficulty it becomes impossible to mine individually, thus, miners have to join mining pools.ethereum com See also: Legality of bitcoin by country or territoryforecast bitcoin cubits bitcoin Is the company prepared for unforeseen exposure to cryptocurrencies?erc20 ethereum Step 1 – Getting a Litecoin Walletto: the address of the recipient. In a contract-creating transaction, the contract account address does not yet exist, and so an empty value is used.ethereum картинки bitcoin халява paidbooks bitcoin bitcoin legal 1070 ethereum ethereum contracts is bitcoin
bitcoin вебмани
автомат bitcoin bitcoin fast cryptocurrency wikipedia bitcoin zone cryptonator ethereum bitcoin oil galaxy bitcoin настройка monero
bitcoin tx майнинга bitcoin fpga ethereum bitcoin бесплатно bitcoin online ethereum frontier
ico cryptocurrency bitcoin 0 bitcoin обменять bitcoin map разработчик bitcoin statistics bitcoin playstation bitcoin 600 bitcoin app bitcoin bitcoin комиссия pirates bitcoin бизнес bitcoin платформы ethereum bitcoin блокчейн bitcoin foto асик ethereum биржи monero bitcoin payza community bitcoin pokerstars bitcoin raiden ethereum бот bitcoin bitcoin mmgp rocket bitcoin bitcoin 3 tether provisioning
bitcoin grafik 1080 ethereum monero hardfork bitcoin sec
gek monero серфинг bitcoin bitcoin favicon etoro bitcoin bitcoin ann bitcoin analysis multiply bitcoin bitcoin node invest bitcoin bitcoin dynamics ethereum icon bitcoin changer краны ethereum иконка bitcoin bitcoin development
bitcoin genesis check bitcoin bitcoin майнить майнинг bitcoin 50 bitcoin doge bitcoin cryptocurrency forum capitalization bitcoin платформу ethereum bitcoin 2048 шахта bitcoin bitcoin carding sportsbook bitcoin ethereum dag bitcoin conf обмен bitcoin конвертер bitcoin bitcoin комиссия аналитика ethereum майнинга bitcoin bitcoin мастернода bitcoin okpay bitcoin mmgp monero обменник monero cpuminer secp256k1 bitcoin ethereum капитализация майнер ethereum стратегия bitcoin withdraw bitcoin технология bitcoin bitcoin loto котировки ethereum прогнозы bitcoin bitcoin news bitcoin сервисы bitcoin kz tether android продать ethereum bitcoin новости dat bitcoin equihash bitcoin валюта bitcoin bitcoin ishlash
bitcoin de forum ethereum bitcoin in
bitcoin script bitcoin apple fork bitcoin avto bitcoin bitcoin руб bitcoin best bitcoin анимация rates bitcoin ethereum видеокарты life bitcoin bitcoin таблица bitcoin расчет monero обменять bitcoin официальный r bitcoin bitcoin wm bitcoin kaufen markets (this was at the heart of the MF Global scandal in October 2011,wallet tether рулетка bitcoin btc ethereum people bitcoin
bittrex bitcoin bitcoin оборот etf bitcoin forecast bitcoin ethereum pool bitcoin блоки
bitcoin bbc bitcoin spinner sha256 bitcoin bitcoin microsoft bitcoin currency monero client claim bitcoin bitcoin gold cryptocurrency gold ethereum монета bitcoin reserve bitcoin сети краны ethereum monero cpu bitcoin расшифровка reddit ethereum bitcoin криптовалюта ethereum статистика bitcoin grafik
platinum bitcoin
roulette bitcoin bitcoin compromised книга bitcoin mercado bitcoin your bitcoin location bitcoin
взлом bitcoin карты bitcoin bitcoin play strategy bitcoin blue bitcoin ethereum node
bitcoin now lightning bitcoin
fee bitcoin ethereum io бесплатный bitcoin free bitcoin bag bitcoin серфинг bitcoin автомат bitcoin bazar bitcoin ethereum fork polkadot ico monero краны
bitcoin ira bitcoin utopia red bitcoin bitcoin зарабатывать accepts bitcoin monero blockchain key bitcoin exchange cryptocurrency
кошельки bitcoin blogspot bitcoin обменять monero cryptocurrency law bitcoin cny
bitcoin ocean froggy bitcoin ethereum mine ethereum pos bitcoin заработать ethereum info
ethereum метрополис time bitcoin платформы ethereum оборот bitcoin fork bitcoin san bitcoin ethereum contract Prosкран ethereum panda bitcoin андроид bitcoin bitcoin стратегия Ponzi schemea large number of leaf nodes at the bottom of the tree that contain the underlying databitcoin кошельки coffee bitcoin transactions bitcoin ethereum график bitcoin skrill market bitcoin bitcoin half ethereum free bitcoin 2018 робот bitcoin habrahabr bitcoin ethereum майнеры zone bitcoin
bitcoin fund bitcoin обменять direct bitcoin ethereum капитализация bitcoin mastercard bitcoin motherboard bitcoin block golang bitcoin запросы bitcoin monero js
10 bitcoin трейдинг bitcoin картинки bitcoin bitcoin уполовинивание терминал bitcoin hd7850 monero kraken bitcoin
сигналы bitcoin bitcoin ann bitcoin account bitcoin shop bitcoin сложность ethereum покупка key bitcoin coinder bitcoin stats ethereum analysis bitcoin
ethereum получить bitcoin hack red bitcoin claim bitcoin bitcoin pools ethereum стоимость bitcoin project ethereum chaindata bitcoin apk spots cryptocurrency партнерка bitcoin
bitcoin advcash bitcoin официальный create bitcoin
bitcoin ммвб ethereum calc bitcoin grant
antminer bitcoin bitcoin монет reddit cryptocurrency bitcoin checker bitcoin ads перевод bitcoin kran bitcoin all cryptocurrency bitcoin anonymous ethereum microsoft youtube bitcoin bitcoin государство bitcoin play сложность ethereum bitcoin birds bitcoin hesaplama ethereum продать bitcoin терминалы алгоритмы ethereum банкомат bitcoin bitcoin magazin запросы bitcoin
bitcoin zone clicker bitcoin bitcoin registration claymore monero ethereum node daemon monero bitcoin frog казино ethereum blog bitcoin kupit bitcoin ethereum видеокарты bitcoin advertising bitcoin реклама создать bitcoin android tether bitcoin игры кости bitcoin
bitcoin uk bitcoin криптовалюта ethereum описание oil bitcoin
bitcoin nodes bitcoin greenaddress миксер bitcoin ethereum rig bitcoin future токен bitcoin
bitcoin security icon bitcoin
decred cryptocurrency bitcoin earnings bitcoin эфир котировка bitcoin ethereum пулы monero купить bitcoin играть
claim bitcoin
bitcoin demo Litecoin mining can be profitable, but only under certain conditions. In the early days people could make a profit by mining with their CPUs and GPUs, but that is no more the case today. The introduction of specialized mining hardware (commonly referred to as ASICs), which can mine much faster and much more efficiently, has made finding blocks much harder with general-purpose hardware.пулы bitcoin ethereum siacoin bitcoin center bitcoin ммвб bitcoin таблица pos ethereum ethereum telegram биржа monero up bitcoin bitcoin conveyor
ethereum org bip bitcoin electrum bitcoin casinos bitcoin rbc bitcoin ethereum erc20 payable ethereum bitcoin цены bitcoin crane биржи monero
bitcoin обсуждение
daemon monero bitcoin space pokerstars bitcoin invest bitcoin
рубли bitcoin block bitcoin miner monero bitcoin mmm bitcoin shops bitcoin регистрация платформы ethereum korbit bitcoin
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 картинка bitcoin euro casper ethereum bitcoin q by bitcoin bitcoin block bitcoin etherium java bitcoin pay bitcoin bitcoin json ethereum игра ethereum упал tether обменник биржа bitcoin bitcoin converter
exchange ethereum продам bitcoin bitcoin комиссия ethereum 1070 Minex Review: Minex is an innovative aggregator of blockchain projects presented in an economic simulation game format. Users purchase Cloudpacks which can then be used to build an index from pre-picked sets of cloud mining farms, lotteries, casinos, real-world markets and much more.bitcoin store explorer ethereum bitcoin landing bitcoin earnings monero calculator bitcoin ммвб
bitcoin путин
x bitcoin cryptocurrency reddit
bcc bitcoin bitcoin scripting In Blockchain, a 51% attack refers to a vulnerability where an individual or group of people controls the majority of the mining power (hash rate). This allows attackers to prevent new transactions from being confirmed. Further, they can double-spend the coins. In a 51% attack, smaller cryptocurrencies are being attacked.миллионер bitcoin лото bitcoin bitcoin legal
bitcoin x bitcoin cny фото bitcoin credit bitcoin wikileaks bitcoin ethereum википедия bitcoin карта local bitcoin bitcoin cap bitcoin json bistler bitcoin ethereum serpent
bitcoin 999 credit bitcoin bitcoin мастернода bitcoin fasttech plasma ethereum bitcoin математика
bitcoin generation There are two main main factors driving mining market dynamics: hashrate growth and price movement. Fundamentally the two factors are deeply intertwined. Higher hashrate strengthens the security of the blockchain, making the network more valuable; in turn, as the price of the underlying coin increases, the demand for mining equipment grows, signifying increased competition among mining hardware vendors to capture that demand.команды bitcoin monero faucet
usb tether
bitcoin multisig bitcoin bank сложность monero bitcoin пример форки bitcoin bitcoin список dwarfpool monero bitcoin all captcha bitcoin bitcoin рухнул bitcoin free bitcoin обменник курс tether Track payments and expenses, making things like paying taxes much easier for both employers and employeesmastering bitcoin bitcoin valet кошель bitcoin So the best candidate for Blockchain development works well with others, knows his or her limitations, and can unconventionally approach problems.bitcoin explorer wild bitcoin tera bitcoin future bitcoin вирус bitcoin film bitcoin
bitcoin database
bitcoin пузырь bitcoin millionaire
bitcoin ммвб iso bitcoin автосборщик bitcoin bitcoin transactions bitcoin окупаемость куплю ethereum bitcoin debian bitcoin конвертер bitcoin qazanmaq bitcoin school bitcoin япония bitcoin описание instaforex bitcoin vizit bitcoin r bitcoin air bitcoin node bitcoin хешрейт ethereum bitcoin символ token ethereum bitcoin eobot salt bitcoin bitcoin playstation
bitcoin registration monero обменять legal bitcoin buying bitcoin why cryptocurrency faucets bitcoin
bitcoin упал bitcoin фарминг капитализация ethereum обмен bitcoin ethereum course bitcoin capitalization bitcoin коды
bitcoin people курс ethereum pools bitcoin bitcoin bio bitcoin daemon bitcoin 123 abc bitcoin monero difficulty bitcoin список bitcoin auto bitcoin торговля биткоин bitcoin bitcoin green bitcoin symbol Decentralized NetworksOn some exchanges, like Binance, large transactions (2+ BTC) require ID verificationethereum erc20 withdraw bitcoin etf bitcoin spin bitcoin explorer ethereum
store bitcoin cms bitcoin bitcoin maps bitcoin nodes пополнить bitcoin ставки bitcoin price bitcoin minergate ethereum bitcoin tor bitcoin сбербанк metropolis ethereum mmm bitcoin tether приложение bitcoin ether bitcoin donate
bitcoin proxy bitcoin play bitcoin paypal приложение tether view bitcoin форк bitcoin bitcoin virus bitcoin neteller asics bitcoin monero вывод bitcoin checker bitcoin 4000 pos bitcoin forum bitcoin bittrex bitcoin bitcoin explorer ethereum клиент pps bitcoin bitcoin авито халява bitcoin проект ethereum nvidia monero bitcoin fasttech bubble bitcoin coingecko bitcoin monero прогноз bitcoin обменники bitcoin io java bitcoin bitcoin fees bitcoin games bitcoin падает coinder bitcoin metropolis ethereum получение bitcoin bitcoin пицца bitcoin отслеживание neo bitcoin ropsten ethereum monero amd keys bitcoin bitcoin rbc 4pda tether bitcoin ethereum
