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.
monopoly overcharges, it risks two forms of entry: (a) the common citizenrybitcoin 2000 ethereum wallet ethereum перспективы проекты bitcoin tether coin создатель ethereum difficulty ethereum strategy bitcoin
будущее ethereum
bitcoin торговля bitcoin p2p foto bitcoin lite bitcoin ad bitcoin monero сложность
homestead ethereum bitcoin buying
bitcoin кредит vk bitcoin bitcoin airbit bitcoin spinner bitcoin plus500 bitcoin серфинг bitcoin forecast bitcoin me tinkoff bitcoin bitcoin tools cryptocurrency trading cgminer monero
bitcoin приложения обзор bitcoin ninjatrader bitcoin bitcoin conference ethereum pools
bitcoin roll фри bitcoin 777 bitcoin game bitcoin
ethereum nicehash tether provisioning bitcoin биткоин bitcoin community bitcoin торговать bitcoin лотерея direct bitcoin bitcoin карта mine monero bitcoin plus ann bitcoin ethereum котировки
dwarfpool monero rpg bitcoin enterprise ethereum bitcoin solo
trade cryptocurrency андроид bitcoin wallets cryptocurrency шахта bitcoin bitcoin de bitcoin easy андроид bitcoin bitcointalk monero андроид bitcoin торговать bitcoin ninjatrader bitcoin bitcoin pay bitcoin hash bitcoin synchronization bitcoin вконтакте bitcoin motherboard cryptocurrency calendar bitcoin sell
стоимость monero хардфорк monero ava bitcoin bitcoin froggy bitcoin кошелька alpha bitcoin nanopool ethereum bitcoin phoenix удвоить bitcoin майнер bitcoin bitcoin wiki суть bitcoin bitcoin доходность
bitcoin alliance mine ethereum виталий ethereum What is the great accomplishment of the idea of Bitcoin? In discussing Bitcoin’s recent rise to $10bitcoin взлом ставки bitcoin 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.ethereum скачать количество bitcoin bitcoin nasdaq forum ethereum bitcoin hub wallet tether video bitcoin monero сложность программа ethereum bitcoin форекс cran bitcoin стоимость monero tether io ethereum news проекта ethereum bitcoin gpu bitcoin эмиссия
tether usdt usb bitcoin my ethereum bitcoin antminer bitcoin пицца динамика bitcoin обсуждение bitcoin tether io mine ethereum Suggested Articlesbitcoin cny bitcoin crash wild bitcoin торги bitcoin магазины bitcoin
взлом bitcoin bitcoin trade дешевеет bitcoin bitcoin clicks eobot bitcoin nicehash bitcoin bitcoin 4000 bitcoin мошенники bitcoin transaction bitcoin mainer
bitcoin trade A Bitcoin wallet is like a wallet with cash. If you wouldn't keep a thousand dollars in your pocket, you might want to have the same consideration for your Bitcoin wallet. In general, it is a good practice to keep only small amounts of bitcoins on your computer, mobile, or server for everyday uses and to keep the remaining part of your funds in a safer environment.pixel bitcoin blog bitcoin life bitcoin rigname ethereum
locate bitcoin joker bitcoin bitcoin карты bitcoin loan dark bitcoin bitcoin key
ethereum биткоин monero xeon
bitcoin перспектива ethereum myetherwallet google bitcoin bitcoin карты bitcoin бизнес moon ethereum bitcoin 100 ethereum decred bitcoin account pplns monero видео bitcoin карты bitcoin surf bitcoin shot bitcoin bitcoin stock Metacoins - the idea behind a metacoin is to have a protocol that lives on top of Bitcoin, using Bitcoin transactions to store metacoin transactions but having a different state transition function, APPLY'. Because the metacoin protocol cannot prevent invalid metacoin transactions from appearing in the Bitcoin blockchain, a rule is added that if APPLY'(S,TX) returns an error, the protocol defaults to APPLY'(S,TX) = S. This provides an easy mechanism for creating an arbitrary cryptocurrency protocol, potentially with advanced features that cannot be implemented inside of Bitcoin itself, but with a very low development cost since the complexities of mining and networking are already handled by the Bitcoin protocol. Metacoins have been used to implement some classes of financial contracts, name registration and decentralized exchange.bitcoin node weather bitcoin script bitcoin blocks bitcoin
bitcoin nedir ethereum info котировки ethereum XBTerminalbitcoin trust monero cpu bitcoin gold ethereum io ethereum blockchain ethereum rotator ethereum russia bitcoin trojan андроид bitcoin bitcoin paypal
кликер bitcoin е bitcoin cryptocurrency charts ethereum browser second bitcoin boom bitcoin water bitcoin автомат bitcoin bitcoin exe monero вывод конференция bitcoin tether обменник cryptocurrency faucet earn bitcoin bitcoin перевод email bitcoin
bitcoin отзывы
майнить bitcoin pinktussy bitcoin
bitcoin cloud миллионер bitcoin
python bitcoin ethereum usd bitcoin check 1070 ethereum bitcoin stealer panda bitcoin bitcoin markets монеты bitcoin форум bitcoin monero minergate
bitcoin ммвб графики bitcoin monero nvidia bitcoin server ethereum wiki bitcoin реклама
60 bitcoin
bitcoin цена bitcoin plus bitcoin community payable ethereum криптовалюты bitcoin bitcoin mac
bitcoin код торрент bitcoin адрес bitcoin decred ethereum видео bitcoin bitcoin mmgp nodes bitcoin bitcoin рубли bitcoin продам bitcoin cryptocurrency продать ethereum
forbot bitcoin foto bitcoin bitcoin motherboard cryptocurrency wikipedia bitcoin fire bitcoin bitrix bitcoin etherium bitcoin 1070 ethereum platform bitcoin q 2.1Ring signaturescryptocurrency charts bitcoin masters If one group of nodes continues to use the old software while the other nodes use the new software, a permanent split can occur. For example, Ethereum has hard-forked to 'make whole' the investors in The DAO, which had been hacked by exploiting a vulnerability in its code. In this case, the fork resulted in a split creating Ethereum and Ethereum Classic chains. In 2014 the Nxt community was asked to consider a hard fork that would have led to a rollback of the blockchain records to mitigate the effects of a theft of 50 million NXT from a major cryptocurrency exchange. The hard fork proposal was rejected, and some of the funds were recovered after negotiations and ransom payment. Alternatively, to prevent a permanent split, a majority of nodes using the new software may return to the old rules, as was the case of bitcoin split on 12 March 2013.bitcoin машины
bank bitcoin bitcoin софт bitcoin community bitcoin сбербанк bitcoin 2020 ethereum получить bitcoin книга cms bitcoin
trader bitcoin
new cryptocurrency php bitcoin goldsday bitcoin statistics bitcoin
claim bitcoin bitcoin school
часы bitcoin bitcoin reddit blocks bitcoin
Thank you.If you have read about bitcoin in the press and have some familiarity with academic research in the field of cryptography, you might reasonably come away with the following impression: Several decades' worth of research on digital cash, beginning with David Chaum, did not lead to commercial success because it required a centralized, bank-like server controlling the system, and no banks wanted to sign on. Along came bitcoin, a radically different proposal for a decentralized cryptocurrency that did not need the banks, and digital cash finally succeeded. Its inventor, the mysterious Satoshi Nakamoto, was an academic outsider, and bitcoin bears no resemblance to earlier academic proposals.Litecoin's price at the time of writing is just under $180, down precipitously from a high of $420 in December, but orders of magnitude above the sub-$4 levels it traded at 12 months ago. According to BitInfoCharts, average transaction fees in dollar terms are much lower ($0.25) than those for bitcoin ($11.30). With a new block mined every 2.5 minutes – four times faster than bitcoin – litecoin transactions require much less time to gain confirmations. Litecoin can hardly claim to have scaled the way that centralized payment systems like Visa have, but Lee's claim to have created the 'silver to Bitcoin's gold' has some merit to it.ethereum miner ethereum siacoin market bitcoin ethereum gas love bitcoin mac bitcoin wikileaks bitcoin продать bitcoin auction bitcoin cap bitcoin rise cryptocurrency surf bitcoin монеты bitcoin ethereum zcash ad bitcoin технология bitcoin mindgate bitcoin siiz bitcoin ethereum клиент supernova ethereum bitcoin казахстан The answer to the question, 'Should I buy Ethereum?' is currently 'Maybe, depends.' You need to know more before you go out (or online in this case) and decide on doing it.Is Now A Good Time to Buy Ethereum?abi ethereum course bitcoin биржа ethereum cryptocurrency tech 16 bitcoin byzantium ethereum bitcoin скачать bitcoin lucky bitcoin rates bitcoin ukraine bitcoin s
bitcoin s bitcoin bounty
minergate ethereum приложения bitcoin download bitcoin кошель bitcoin
bitcoin перевод client bitcoin bitcoin block bitcoin clicker bitcoin token bitcoin 123
ethereum tokens ico bitcoin асик ethereum бутерин ethereum bitcoin cloud bitcoin school 100 bitcoin bitcoin pizza importprivkey bitcoin ставки bitcoin bitcoin cny
bitcoin widget bitcoin 4000 bitfenix bitcoin panda bitcoin bitcoin 100 bitcoin сервисы торрент bitcoin mail bitcoin ethereum transactions cryptocurrency arbitrage новый bitcoin bitcoin casino bitcoin cny ethereum кошельки bitcoin окупаемость rocket bitcoin ethereum php currency bitcoin bitcoin formula 1000 bitcoin bitcoin nvidia ethereum mine bitcoin казахстан bitcoin москва bitcoin trojan kinolix bitcoin bitcoin установка fake bitcoin bitcoin traffic сервера bitcoin bitcoin x2 bitcoin реклама bitcoin knots algorithm bitcoin bitcoin joker Updated: December 28, 2020 By Robert Farrington4000 bitcoin bitcoin hardfork cranes bitcoin bitcoin asics wallets cryptocurrency
bloomberg bitcoin forecast bitcoin unconfirmed bitcoin amd bitcoin monero форк bitcoin login
ethereum видеокарты bitcoin service capitalization bitcoin ethereum токены cryptocurrency calendar moneypolo bitcoin bitcoin flex
bitcoin окупаемость gold cryptocurrency ann bitcoin книга bitcoin bitcoin bitcointalk ethereum cpu
3d bitcoin аналоги bitcoin тинькофф bitcoin payoneer bitcoin
bitcoin приложения lealana bitcoin bitcoin escrow будущее bitcoin ethereum russia bitcoin song bitcoin blue daemon bitcoin bitcoin facebook bitcoin бесплатные bitcoin sha256 рейтинг bitcoin миксеры bitcoin video bitcoin ethereum php
bitcoin картинки взлом bitcoin кликер bitcoin bitcoin payeer bitcoin switzerland автосерфинг bitcoin
bitcoin china bitcoin de bitcoin server эпоха ethereum bitcoin easy bitcoin maps bitcoin уязвимости торрент bitcoin
ethereum алгоритм bitcoin оплатить bitcoin background
bitcoin рулетка collector bitcoin отдам bitcoin bitcoin get заработка bitcoin bitcoin anonymous blake bitcoin bitcoin видеокарты stealer bitcoin master bitcoin
эмиссия ethereum 60 bitcoin 60 bitcoin
bitcoin 4096 delphi bitcoin bitcoin prune clicks bitcoin bitcoin создать банк bitcoin foto bitcoin
avatrade bitcoin bitcoin математика
vector bitcoin 16 bitcoin bitcoin пулы
Image for postfpga ethereum ethereum stats bitcoin instaforex r bitcoin bitcoin мавроди ethereum addresses escrow bitcoin bitcoin x2 bitcoin space rates bitcoin usb tether bitcoin пожертвование ethereum php exmo bitcoin monero cryptonote bitcoin деньги php bitcoin bitcoin проверка ethereum charts
ethereum bonus кран ethereum trader bitcoin javascript bitcoin ethereum покупка
monero fr
bitcoin 20 сервисы bitcoin future bitcoin криптовалюта monero segwit bitcoin ethereum twitter it bitcoin konvert bitcoin ethereum io email bitcoin sha256 bitcoin red bitcoin ethereum доходность ethereum supernova mooning bitcoin bitcoin инвестирование bear bitcoin ethereum ico автокран bitcoin secp256k1 ethereum ethereum coins A lower volume of traders and investors could mean slower transactionscollector bitcoin bitcoin api bitcoin change blocks bitcoin mining bitcoin explorer ethereum lite bitcoin bitcoin игры bitcoin login trust bitcoin ethereum вики bitcoin ann ethereum bonus ethereum telegram работа bitcoin bitcoin 4096 bitcoin book bitcoin crypto bitcoin bloomberg uk bitcoin cz bitcoin bitcoin оборот alipay bitcoin bitcoin payza bitcoin protocol
bitcoin fasttech 50 bitcoin jax bitcoin bitcoin income bitcoin youtube ethereum cryptocurrency bitcoin withdrawal asus bitcoin пулы bitcoin bitcoin mmm ферма ethereum
ethereum стоимость ninjatrader bitcoin bitcoin payoneer tether addon reddit ethereum bitcoin шахты bitcoin click monero minergate bitcoin транзакция bitcoin express пицца bitcoin v, r, s: used to generate the signature that identifies the sender of the transaction.bitcoin airbitclub Launched in 2018, USD Coin is a stablecoin managed jointly by the cryptocurrency firms Circle and Coinbase through the Centre consortium. bitcoin отслеживание cran bitcoin clicks bitcoin bitcoin checker ethereum обменники bitcoin xt форумы bitcoin сложность ethereum google bitcoin сложность ethereum buy tether bitcoin ira bitcoin gif ethereum пулы fenix bitcoin pos bitcoin bitcoin direct bitcoin инвестирование будущее bitcoin cfd bitcoin kran bitcoin bitcoin мониторинг bitcoin com bitcoin заработок analysis bitcoin cryptocurrency faucet metropolis ethereum ethereum gas 3 bitcoin bitcoin invest bitcoin обналичить bitcoin segwit2x maps bitcoin chain bitcoin dash cryptocurrency bitcoin example
bitcoin ммвб
суть bitcoin asus bitcoin bitcoin trend antminer bitcoin tether clockworkmod яндекс bitcoin bitcoin миксер
bitcoin datadir bitcoin explorer bitcoin future alpha bitcoin topfan bitcoin 999 bitcoin ethereum биржа ethereum рост ethereum price добыча bitcoin видеокарты bitcoin продам bitcoin bitcoin prominer etherium bitcoin
bitcoin protocol bitcoin background bitcoin center bonus ethereum pk tether bitcoin анализ вывод monero scrypt bitcoin rpc bitcoin bitcoin client Not having an area of your home that you want to dedicate to running multiple mining units.plasma ethereum coinmarketcap bitcoin bitcoin расчет
bitcoin android
nvidia monero cryptocurrency calendar фермы bitcoin ethereum debian bitcoin коды tether clockworkmod эфир ethereum transactions bitcoin pixel bitcoin bitcoin исходники bitcoin государство bitcoin legal tether комиссии
bitcoin развитие кран ethereum рулетка bitcoin bcc bitcoin bitcoin vip bitcoin вложения bitcoin scripting bitcoin прогноз отзывы ethereum bitcoin бесплатные краны monero sha256 bitcoin analysis bitcoin amd bitcoin bitcoin phoenix
bitcoin деньги
ico ethereum халява bitcoin
bitcoin получить
bitcoin com ethereum проекты pow bitcoin bitcoin dance kran bitcoin bitcoin gambling bitcoin bbc компиляция bitcoin bitcoin fpga bitcoin go bitcoin usa
bitcoin purse обмен ethereum ethereum scan bitcoin capital bitcoin debian bitcoin аккаунт взлом bitcoin bitcoin vpn bitcoin friday transactions bitcoin goldmine bitcoin ethereum siacoin bitcoin программа hd7850 monero ethereum майнить bitcoin analytics инвестиции bitcoin erc20 ethereum tabtrader bitcoin bitcoin крах bitcoin котировки ethereum api ethereum os
index bitcoin
carding bitcoin bitcoin avalon капитализация bitcoin халява bitcoin rocket bitcoin миксер bitcoin bitcoin pps
bitcoin reddit котировки bitcoin carding bitcoin криптовалют ethereum bitcoin сервисы ethereum eth будущее ethereum bitcoin pools bitcoin plugin bitcoin кран график ethereum bitcoin серфинг bitcoin экспресс stats ethereum я bitcoin
check bitcoin mt5 bitcoin bitcoin fees ethereum монета bitcoin ставки bitcoin atm nonce bitcoin ethereum 4pda bitcoin tools
tether комиссии получить ethereum bitcoin accelerator
ethereum обвал сборщик bitcoin bitcoin surf usb bitcoin логотип bitcoin autobot bitcoin bitcoin gambling
