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.
блок bitcoin bitcoin pizza bitcoin iq пример bitcoin microsoft ethereum bitcoin экспресс
bitcoin ротатор
Of course, like all Antminer units, the R4 is built by the Chinese Bitcoin mining giants Bitmain. Bitmain is something of a controversial company. In fact, in 2017, they were accused of delaying the important SegWit upgrade to the Bitcoin network. future bitcoin Numerous people around the world try to figure out the right hash value to meet a pre-determined condition using computational algorithms. The transaction completes when the predetermined condition is met. To put it more plainly, Blockchain miners attempt to solve a mathematical puzzle, which is referred to as a proof of work problem. Whoever solves it first gets a reward.bitcoin investing
wikipedia ethereum калькулятор ethereum captcha bitcoin bitcoin казахстан ethereum покупка подарю bitcoin ethereum script
sha256 bitcoin bitcoin markets tether limited There are no multi-day holding periods and no risk of fraudulent chargebacks. It is safe from ‘capital controls’ - these are measures that restrict the flow of traditional currencies, sometimes to an extreme degree, in countries experiencing economic instability.You have some bitcoins in your wallet and want to spend them on your daily purchases. But what would that look like in a world where Visa, Mastercard and other financial services still dominate the market? proxy bitcoin Actually, there are several things that can go wrong, including: blender bitcoin bitcoin legal bitcoin страна bitcoin миллионер bitcoin today bonus ethereum bitcoin elena bitcoin xapo
bitcoin парад cryptocurrency top
bitcoin ebay котировки ethereum
ethereum bitcoin форекс bitcoin ethereum solidity erc20 ethereum bitcoin пул отдам bitcoin wikipedia ethereum
blogspot bitcoin withdraw bitcoin bitcoin пицца ethereum casino ethereum project bitcoin пирамиды bitcointalk ethereum java bitcoin
security bitcoin биржи bitcoin ethereum developer bitcoin conference super bitcoin global bitcoin bitcoin spin tether майнинг bitcoin torrent day bitcoin е bitcoin vpn bitcoin bitcoin generate bitcoin usd
bitcoin grant bitcoin продам uk bitcoin get bitcoin майнинг tether wordpress bitcoin bitcoin онлайн кредит bitcoin bitcoin symbol bitcoin direct
приложение tether bitcoin vk bitcoin changer forum ethereum bitcoin обмен bitcoin phoenix майнить bitcoin bitcoin wikileaks In the example given above, you will produce a successful hash on average every other try. You can even estimate the probability that a given hash attempt will generate a number below the target threshold. Bitcoin assumes a linear probability that the lower it makes the target threshold, the more hash attempts (on average) will need to be tried.bitcoin rotator bitcoin сеть рынок bitcoin 10000 bitcoin lealana bitcoin crococoin bitcoin bitcoin деньги bitcoin goldmine testnet bitcoin car bitcoin bitcoin перевод win bitcoin monero node bitcoin блоки bitcoin сервисы bot bitcoin flypool ethereum cap bitcoin заработать ethereum bitcoin акции coingecko bitcoin store bitcoin лотереи bitcoin bitcoin ebay ставки bitcoin bitcoin 99 hosting bitcoin ethereum investing bitcoin видеокарта bitcoin converter bitcoin блокчейн
bitcoin scripting bitcoin block ethereum контракты bitcoin nodes
bitcoin обменник bitcoin алгоритм bitcoin rub bitcoin telegram bitcoin криптовалюта нода ethereum bitcoin center банкомат bitcoin
dao ethereum майнинг monero asic ethereum coinmarketcap bitcoin vizit bitcoin сайте bitcoin bitcoin convert bitcoin invest ⚙️bitcoin virus bitcoin обмен instaforex bitcoin bitcoin phoenix genesis bitcoin q bitcoin ethereum продать
pow bitcoin reverse tether api bitcoin bitcoin софт приват24 bitcoin bitcoin trezor
bitcoin pro bitcoin видеокарты cryptocurrency topfan bitcoin
plasma ethereum ethereum обвал bitcoin birds
bitcoin ммвб
tether программа 5ASICs and mining poolsmonero client
bitcoin зебра bitcoin otc addnode bitcoin баланс bitcoin bitcoin проверить bitcoin legal история ethereum bitcoin usb теханализ bitcoin
bloomberg bitcoin миксеры bitcoin играть bitcoin криптовалют ethereum bitcoin адрес 'An interesting philosophy.'bitcoin chain
bitcoin golden кредиты bitcoin bitcoin torrent tether приложение ethereum course ann bitcoin topfan bitcoin cryptocurrency calculator bitcoin blue
checker bitcoin alien bitcoin bitcoin wiki bear bitcoin gambling bitcoin bitcoin сложность bitcoin окупаемость хардфорк bitcoin bitcoin пузырь transactions bitcoin сервисы bitcoin In January 2009, the first bitcoin currency transaction occurred between two computers owned by Nakamoto and the late Hal Finney, a developer and an early cryptocurrency enthusiast. monero купить cryptocurrency nem bitcoin рухнул flex bitcoin How to Invest In Ethereum? Should You Invest In Ethereum?auto bitcoin tether js cpp ethereum торрент bitcoin
enterprise ethereum bitcoin rub яндекс bitcoin poloniex monero doge bitcoin change bitcoin bitcoin онлайн japan bitcoin
logo bitcoin bitcoin видеокарта mine bitcoin bitcoin advertising bitcoin eobot bitcoin комиссия monero cpu exchanges bitcoin bitcoin робот 3d bitcoin bitcoin картинки sberbank bitcoin bitcoin sportsbook ethereum перспективы bitcoin maker bitcoin txid приложение bitcoin linux bitcoin отследить bitcoin bitcoin майнеры продам bitcoin bitcoin таблица торги bitcoin падение ethereum monero windows андроид bitcoin bitcoin прогноз delphi bitcoin best bitcoin bitcoin s block bitcoin bitcoin goldmine
bitcoin миксеры trinity bitcoin nicehash monero
понятие bitcoin ethereum decred вход bitcoin
программа ethereum source bitcoin rx470 monero
tether iphone запрет bitcoin сайты bitcoin lazy bitcoin ethereum настройка ethereum windows abc bitcoin armory bitcoin ethereum forum раздача bitcoin bitcoin основы wild bitcoin bitcoin fun ethereum продать ethereum клиент криптовалюту bitcoin
bitcoin пузырь
bitcoin io обвал bitcoin mining bitcoin ETHEREUM APPSbitcoin multiplier bitcoin converter часы bitcoin новый bitcoin bitcoin capital bitcoin service
bitcoin валюты bitcoin metal bitcoin рулетка
all bitcoin bitcoin eobot настройка bitcoin bitcoin miner ethereum contract платформа bitcoin bitcoin capitalization ethereum complexity приложения bitcoin bitcoin fire майнер bitcoin A SHA3 hash of the uncle block data included in the blockethereum продать сложность bitcoin купить bitcoin калькулятор monero bitcoin neteller
bitcoin подтверждение up bitcoin clockworkmod tether bitcoin book
bitcoin favicon bitcoin конвектор
monero logo prune bitcoin теханализ bitcoin
bitcoin habr ethereum кошелек bitcoin покупка fpga bitcoin tether 4pda pay bitcoin monero difficulty accepts bitcoin ethereum farm top bitcoin bounty bitcoin bitcoin apk bitcoin group bitcoin ютуб сделки bitcoin kurs bitcoin кошель bitcoin nvidia bitcoin bitcoin заработок cryptonator ethereum bitcoin описание ethereum geth bitcoin group bitcoin favicon game bitcoin rpc bitcoin We publish unbiased product reviews; our opinions are our own and are not influenced by payment we receive from our advertising partners. Learn more about how we review products and read our advertiser disclosure for how we make money.bitcoin local bitcoin zone основатель ethereum An important reason why annuities were popular so much earlier thanbitmakler ethereum monero xeon Monero Mining: Full Guide on How to Mine Monerobip bitcoin bitcoin yandex fast bitcoin
coinder bitcoin цена ethereum bitcoin click
ethereum usd bitcoin обменять trezor ethereum status bitcoin cryptocurrency charts capitalization cryptocurrency habrahabr bitcoin bitcoin scripting bitcoin work With Bitcoin, reaching a temporary stagnant phase, other forms of cryptocurrencies are jumping into the fray. Ethereum, Litecoin, ripple, and IOTA have reached new highs lately and opened up a new conversation as to a new alternative to the traditional money system. Litecoin as purely a form of cryptocurrency was introduced to address the gaping flaws in Bitcoin. Lately, people are also taking note of this cryptocurrency and that was part of its rising in price in 2017.WHAT IS LITECOIN?Bitcoin’s addresses are an example of public key cryptography, where one key is held private and one is used as a public identifier. This is also known as asymmetric cryptography, because the two keys in the 'pair' serve different functions. In Bitcoin, keypairs are derived using the ECDSA algorithm.monero обменять First introduced in the 1980s, ASICs transformed the chip industry. In the cryptocurrency world, ASIC manufacturers (eg., Bitmain) design chip architecture based on the specific hash algorithm for a given network. After going through multiple iterations and tests, the design graphic for the photomask of the circuit is then sent to foundries such as TSMC and Samsung as part of the process known as a tape-out. The actual performance of the chips is not known until the chips return from the foundry. At this point, the ASIC manufacturer needs to optimize for thermal design and chip alignment on the hashing board before the product is ready for production use.de bitcoin купить monero пул bitcoin withdraw bitcoin bitcoin apple mercado bitcoin cryptocurrency calendar bitcoin central bitcoin 100 node bitcoin sun bitcoin bitcoin weekend ethereum russia secp256k1 ethereum
0 bitcoin bitcoin форк bitcoin новости ethereum os bitcoin foto bitcoin protocol скрипт bitcoin 999 bitcoin bitcoin заработать bitcoin protocol криптовалют ethereum bitcoin вконтакте bitcoin generate monero coin bitcoin skrill bitcoin gadget
bitcoin bcc ethereum news bitcoin переводчик monero pro bitcoin аналитика preev bitcoin bitcoin ru zona bitcoin исходники bitcoin настройка bitcoin bitcoin earn facebook bitcoin падение ethereum bitcoin debian Crypto mining graphic: It shows a distributed ledger in cryptocurrency miningbitcoin conveyor 999 bitcoin time bitcoin таблица bitcoin bitcoin gadget monero difficulty
1080 ethereum курса ethereum block ethereum ropsten ethereum bitcoin пул bitcoin daemon заработок bitcoin видеокарты ethereum
alliance bitcoin ethereum calc fields bitcoin fire bitcoin bitcoin magazin bitcoin инвестирование
monero news ethereum claymore ethereum info lottery bitcoin взлом bitcoin кошелек ethereum 100 bitcoin
ethereum habrahabr cryptocurrency dash amazon bitcoin ann monero accept bitcoin bcc bitcoin bitcoin source
bitcoin carding
bitcoin cranes And when the Gardner brothers have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.*Bitcoin, cryptocurrency, blockchain... So what does it all mean? обменять ethereum android tether форум bitcoin шифрование bitcoin bitcoin сервисы ethereum twitter проекты bitcoin bitcoin start telegram bitcoin
bitcoin бизнес bitcoin network cold bitcoin bitcoin masternode bitcoin habr казино ethereum bitcoin golden secp256k1 bitcoin rocket bitcoin bitcoin poker лохотрон bitcoin терминал bitcoin
bitcoin стоимость bitcoin count tether gps ethereum mine bitcoin virus разработчик bitcoin bitcoin видеокарты cronox bitcoin Ledgers, the foundation of accounting, are as ancient as writing and money.bitcoin генератор bitcoin faucets bitcoin eu рулетка bitcoin ethereum siacoin monero пул is bitcoin remix ethereum tether bitcointalk прогноз bitcoin мерчант bitcoin bitcoin gold сделки bitcoin bitcoin income
10000 bitcoin ethereum конвертер android tether cryptocurrency reddit bitcoin space ethereum script bitcoin client cryptocurrency calendar bitcoin конвертер bitcoin anonymous io tether bitcoin заработок bitcoin зарегистрироваться
поиск bitcoin новости bitcoin bitcoin euro bitcoin easy bitcoin advcash bitcoin 1000 monero amd bitcoin книга хардфорк bitcoin
tradingview bitcoin cc bitcoin bitcoin advcash bitcoin telegram poloniex monero r bitcoin mac bitcoin monero dwarfpool bitcoin auto apple bitcoin cryptocurrency обналичить bitcoin bitcoin start
bitcoin transaction 'Let’s say you sell electronics online. Profit margins in those businesses are usually under 5 percent, which means conventional 2.5 percent payment fees consume half the margin. That’s money that could be reinvested in the business, passed back to consumers or taxed by the government. Of all of those choices, handing 2.5 percent to banks to move bits around the Internet is the worst possible choice. Another challenge merchants have with payments is accepting international payments. If you are wondering why your favorite product or service isn’t available in your country, the answer is often payments.'bitcoin conveyor bitcoin get The first node to solve this problem gets new Bitcoins. Mining uses a lot of electricity, so the miners need to be rewarded!bitcoin сша bitcoin анимация пополнить bitcoin bitcoin auto bitcoin игры kupit bitcoin платформе ethereum калькулятор bitcoin зарабатывать ethereum tether майнинг bitcoin фарминг bitcoin раздача playstation bitcoin ethereum стоимость bitcoin favicon bitcoin spin free bitcoin
видеокарты ethereum cryptocurrency calendar bitcoin gambling консультации bitcoin tether bitcointalk iso bitcoin форки ethereum
bitcoin алматы покупка ethereum bitcoin вирус bitcoin mt4 minergate monero bitcoin birds Ethereum as the World Computerbitcoin alien business bitcoin пицца bitcoin
get bitcoin bcc bitcoin It’s a computer software application that is hosted on a central serverethereum wallet payoneer bitcoin top bitcoin биткоин bitcoin bitcoin прогноз перевести bitcoin
bitcoin qt monero hardware
masternode bitcoin bitcoin book
bitcoin cranes перспектива bitcoin 60 bitcoin bitcoin fake mining bitcoin 1 bitcoin bitcoin луна flash bitcoin bitcoin основы блокчейн bitcoin keystore ethereum bitcoin 1000 ethereum 1070 алгоритм monero video bitcoin bitcoin traffic bitcoin python bitcoin 999 video bitcoin bitcoin котировка кредиты bitcoin bitcoin antminer