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.
ethereum проблемы txid ethereum monero client mixer bitcoin bitcoin mainer пицца bitcoin home bitcoin
платформе ethereum
bitcoin lucky direct bitcoin отзыв bitcoin bitcoin elena
bitcoin widget
konvertor bitcoin
кости bitcoin book bitcoin monero core security bitcoin клиент bitcoin bitcoin today monero курс ethereum fork калькулятор ethereum bitcoin биржи monero amd
monero майнить armory bitcoin apk tether bitcoin people
обзор bitcoin bitcoin information difficulty ethereum bitcoin atm кредиты bitcoin bitcoin novosti
bitcoin кэш For Bitcoin miners that are on a budget, one of the best Bitcoin mining rigs around is the Antminer T9+. It can be picked up much more cheaply that most of the other devices on this list. However, don’t let the price tag fool you — it’s still a decent machine. халява bitcoin cryptocurrency calendar If you are serious about Monero mining, then using a GPU is a better option. Even though it requires a larger investment, it offers a significantly higher hash rate.rx580 monero скачать ethereum bitcoin security bitcoin stealer bitcoin school bitcoin стоимость ethereum bitcoin monero daily bitcoin котировки bitcoin bitcoin nachrichten 4pda tether bitcoin koshelek 6000 bitcoin monero кран monero майнить bitcoin algorithm
ethereum foundation протокол bitcoin bitcoin миксер программа tether bitcoin обучение bitcoin биржа casino bitcoin
bitcoin пицца
exmo bitcoin instant bitcoin converter bitcoin bitcoin серфинг ethereum usd bitcoin приват24 monero dwarfpool scrypt bitcoin bitcoin окупаемость
ethereum метрополис
bitcoin com bitcoin мавроди reverse tether bitcoin зарегистрироваться bitcoin rotator
iobit bitcoin bitcoin ru ethereum forks pools bitcoin bitcoin доходность bitcoin motherboard капитализация ethereum вложения bitcoin bitcoin транзакция data bitcoin bitcoin monkey index bitcoin bitcoin машины ethereum stats bitcoin script bitcoin blue lavkalavka bitcoin bittrex bitcoin bitcoin grant bitcoin регистрации remix ethereum
bitcoin allstars bitcoin упал bitcoin drip wikileaks bitcoin bitcoin demo bitcoin динамика usb bitcoin bitcointalk ethereum
bitcoin faucets обмен ethereum spots cryptocurrency
air bitcoin
создатель bitcoin ethereum core bitcoin продать bitcoin перевод roulette bitcoin anomayzer bitcoin часы bitcoin
bitcoin forbes bitcoin book bitcoin продать иконка bitcoin solo bitcoin bitcoin register mine monero debian bitcoin проблемы bitcoin reverse tether
skrill bitcoin стоимость bitcoin bitcoin coingecko monero новости bitcoin earn форк bitcoin bitcoin widget bitcoin token bitcoin click bitcoin adress chart bitcoin logo bitcoin bitcoin hardfork bitcoin drip rigname ethereum трейдинг bitcoin bitcoin credit покупка bitcoin bitcoin png bitcoin пул 2018 bitcoin red bitcoin alien bitcoin особенности ethereum bitcoin android cryptocurrency index bitcoin scam bitcoin torrent bitcoin reward tether приложение bitcoin capital bux bitcoin If you believe in Ethereum’s future, investing long-term into this coin now maybe something you would like to do. If you do not believe, do not invest. Simple, right?bitcoin satoshi tether bitcointalk bitcoin мошенничество litecoin bitcoin key bitcoin 'Certainly, the Federal Reserve Note is superior to gold, and that’s why we use it today,'And to think, that number is just for the people who are mining Bitcoin specifically!bitcoin scam ethereum аналитика boxbit bitcoin форк bitcoin boxbit bitcoin пулы bitcoin bitcoin cranes
pool monero bitcoin base bitcoin clicker
bitcoinwisdom ethereum инвестирование bitcoin bitcoin income forecast bitcoin monero пул bitcoin forex история ethereum investment bitcoin polkadot su bitcoin cash bitcoin капитализация bitcoin миллионеры pool bitcoin
bitcoin магазины cryptocurrency gold bitcoin moneybox сервер bitcoin bitcoin qiwi mikrotik bitcoin обменник bitcoin
ethereum info
bitcoin nvidia bitcoin surf rpg bitcoin bitcoin super bitcoin зебра maps bitcoin bitcoin click lootool bitcoin time bitcoin fasterclick bitcoin bitcoin hunter Trading Economics has a list of the size of the M2 money supply of each country, converted to USD. The United States has over $18 trillion.удвоитель bitcoin Hardware wallets are becoming a preferred choice to secure a wallet in an offline mode. These are small devices which are water and virus proof and even support multi signature transactions. They are convenient for sending and receiving virtual currency, have a micro storage device backup and QR code scan camera. Pi-Wallet is an example of a hardware wallet.обмен tether bitcoin терминал форумы bitcoin monero краны ethereum api bitcoin mmgp bitcoin neteller bitcoin 99 wikileaks bitcoin bitcoin монет testnet bitcoin love bitcoin
change bitcoin луна bitcoin bitcoin nvidia bitcoin машина Bitcoin Benefits from Randomnessbitcoin matrix paypal bitcoin криптовалюту bitcoin alpari bitcoin настройка bitcoin индекс bitcoin сбор bitcoin bitcoin курс programming bitcoin bitcoin tools ethereum stratum е bitcoin ethereum stats hosting bitcoin получить bitcoin ethereum miners bitcoin darkcoin bitcoin loan bitcoin сайты
planet bitcoin flash bitcoin доходность ethereum ethereum краны ethereum web3 microsoft ethereum bitcoin crane autobot bitcoin суть bitcoin live bitcoin bitcoin withdrawal vector bitcoin bitcoin trend bitcoin кошелек bitcoin currency ico bitcoin bitcoin lucky видеокарта bitcoin проект ethereum monero ico x2 bitcoin site bitcoin bitcoin мониторинг pull bitcoin ethereum 1070 bitcoin tools ethereum code Bitcoin, on the other hand, maximizes security and decentralization, at the cost of speed. By keeping the block size small, it makes it possible for people all over the world to run their own full nodes, which can be used to verify the entire blockchain. Widespread node distribution (over 10,000 nodes) helps ensure decentralization and continual verification of the blockchain.bitcoin sec ethereum доходность up bitcoin monero gpu block ethereum криптовалюта monero monero miner bitcoin center start bitcoin explorer ethereum bitcoin split bitcoin майнер bitcoin euro bitcoin рубль ethereum blockchain blogspot bitcoin casascius bitcoin chvrches tether bitcoin litecoin loco bitcoin bitcoin farm clicker bitcoin bitcoin apk
bitcoin курс polkadot блог bitcoin qiwi bitcoin vpn
wikipedia ethereum раздача bitcoin dark bitcoin вход bitcoin wallet cryptocurrency fake bitcoin forecast bitcoin bitcoin 20 bitcoin cgminer grayscale bitcoin
ethereum casino vizit bitcoin bitcoin map bitcoin новости q bitcoin sgminer monero fork ethereum
bitcoin talk bitcoin прогноз bitcoin сервера bitcoin bitcointalk bitcoin торговать bitcoin терминалы bitcoin in bitcoin girls roboforex bitcoin
bitcoin api торрент bitcoin bitcoin халява wired tether bitcoin vpn advcash bitcoin ethereum сложность bitcoin airbit ethereum complexity reddit cryptocurrency
bitcoin block monero пул bitcoin 3 ethereum картинки claymore monero xbt bitcoin
bitcoin etf
uk bitcoin bitcoin блоки It is also widely traded on most major cryptocurrency exchanges (including Kraken!), making its market one of the more liquid globally.Crypto Mining Explanatorygif bitcoin bitcoin xyz ledger bitcoin flypool ethereum bitcoin keys bitcoin coingecko
bitcoin neteller bitcoin 100 auction bitcoin bitcoin аналоги mine monero 1,600 years later. The movable type printing press already existed beforeбиржа ethereum Bananas grow on trees. Money does not, and bitcoin is the force that reawakens everyone to the reality that was always the case. Similarly, there is no such thing as a free lunch. Everything is being paid for by someone. When governments and central banks can no longer create money out of thin air, it will become crystal clear that backdoor monetary inflation was always just a ruse to allocate resources for which no one was actually willing to be taxed. In common sense, there is no question. There may be debate but bitcoin is the inevitable path forward. Time makes more converts than reason.A transaction is recorded in the blockchain’s state transition if it meets several criteria: a valid digital signature must be present for the Bitcoins being spent, and the keypair must control a sufficient balance of bitcoins to pay the transaction.bitcoin 2018 safe bitcoin bitcoin flapper bitcoin payment The world has about $400 trillion in wealth if translated to U.S. dollars. This consists mainly of stocks, bonds, real estate, business equity, and cash.In late 2016, the network was under DDoS attack. This increased the uncle rate, therefore causing a temporary rise in issuance rate.автокран bitcoin Tweetbitcoin register fire bitcoin зарегистрировать bitcoin bitcoin хешрейт
tether верификация продать ethereum bitcoin продам сеть bitcoin github bitcoin
dao ethereum bitcoin pools cryptocurrency dash bitcoin forum analysis bitcoin
avto bitcoin кредиты bitcoin
bitcoin protocol раздача bitcoin tether limited bitcoin адрес dance bitcoin bitcoin авито tether mining bitcoin xbt bitcoin atm global bitcoin difficulty ethereum ethereum рост 2016 bitcoin
bitcoin linux bitcoin red forum ethereum hd7850 monero bitcoin config
blog bitcoin
ethereum прогноз bitcoin блок 1 bitcoin bitcoin информация bitcoin poloniex платформы ethereum key bitcoin donate bitcoin monster bitcoin dat bitcoin акции ethereum tether gps bitcoin golden робот bitcoin понятие bitcoin bitcoin purse bitcoin make bitcoin farm collector bitcoin конвертер monero ethereum перевод widget bitcoin создатель bitcoin ethereum stats bitcoin 100 Learn how to buy Siacoin and find your best places where to buy Siacoin by following this complete how to buy Siacoin guide.mmm bitcoin Only the computer that correctly guesses the hash can add the block to the chain. Proof-of-work requires computational power and the process is neither quick or cheap. To cheat the network would require so much of an investment that it is not financially viable for someone to try and amend the blockchain. This is the main security feature of the Bitcoin (and other cryptocurrency) networks.flypool monero
ethereum 1070 bitcoin x2 monero nvidia ethereum blockchain
алгоритм monero
bitcoin landing bitcoin сервисы
bitcoin elena monero address bitcoin explorer оборудование bitcoin
ethereum контракт bitcoin wikileaks краны monero bitcoin книги