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 100
ann ethereum
start bitcoin
tether криптовалюта bitcoin chart фото ethereum bitcoin проблемы bitcoin twitter
ethereum bitcointalk bitcoin rigs
alipay bitcoin 2x bitcoin bitcoin code bitcoin рублях bitcoin москва ethereum контракты добыча bitcoin attack bitcoin putin bitcoin bitcoin flapper
bitcoin get bitcoin миксеры bitcoin linux bitcoin casino txid bitcoin json bitcoin bitcoin com ann monero This prohibitive hardware requirement is one of the biggest security measures that deter people from trying to manipulate the bitcoin system.swarm ethereum bitcoin song bitcoin faucets bitcoin сигналы
bitcoin cap bitcoin ann bitcoin express bounty bitcoin
blockchain ethereum bitcoin торги
bitcoin ann opencart bitcoin The result of bitcoin mining is twofold. First, when computers solve these complex math problems on the bitcoin network, they produce new bitcoin (not unlike when a mining operation extracts gold from the ground). And second, by solving computational math problems, bitcoin miners make the bitcoin payment network trustworthy and secure by verifying its transaction information.bitcoin motherboard bitcoin экспресс ethereum news алгоритм bitcoin asic ethereum bitcoin start ethereum stratum bloomberg bitcoin ethereum асик bitcoin minergate 1 ethereum
bitcoin сигналы We also recently saw Maxwell conduct the first successful zero-knowledge contingent payment on the bitcoin network. ZKCP is a transaction protocol that allows a buyer to purchase information from a seller using bitcoin in a trustless manner. The purchased information is only transferred if the payment is made, and it is guaranteed to be transferred if the payment is made. The buyer and seller do not need to trust each other or depend on arbitration by a third party.bitcoin автомат buy tether bitcoin fpga cryptocurrency bitcoin maps ethereum токены monero график mac bitcoin bitcoin майнинга bitcoin half get bitcoin инструкция bitcoin 0 bitcoin bitcoin roulette bitcoin preev wikipedia ethereum bitcoin china 'a change in protocol' orethereum decred Cardano vs Ethereum: The Ultimate ComparisonSchnorr signatures offer a way to consolidate signature data, reducing the space it takes up within a bitcoin block (and enhancing privacy). Combined with SegWit, this could allow a much greater number of transactions, without changing the block size limitобменник ethereum bitcoin bcc добыча bitcoin satoshi bitcoin bitcoin бонусы bitcoin change bitcoin legal bitcoin спекуляция
best bitcoin trade cryptocurrency bitcoin transaction stealer bitcoin сайте bitcoin
ethereum форум difficulty monero invest bitcoin total cryptocurrency bitcoin center добыча bitcoin direct bitcoin bitcoin txid bitcoin prices курсы bitcoin
bitcoin mmgp bitcoin mmgp bitcoin etherium bitcoinwisdom ethereum
bitcoin приват24 bitcoin продать прогнозы bitcoin развод bitcoin ethereum api bitcoin mastercard bitcoin suisse ethereum api
steam bitcoin
4000 bitcoin koshelek bitcoin bitcoin оборот bitcoin telegram p2pool ethereum 60 bitcoin суть bitcoin ethereum bitcoin total cryptocurrency кран bitcoin отзывы ethereum cpuminer monero copay bitcoin bitcoin cnbc bitcoin data ethereum майнить the ethereum source bitcoin
konverter bitcoin монета ethereum bitcoin planet bitcoin опционы bitcoin перевод antminer ethereum
gold cryptocurrency кран bitcoin bitcoin hesaplama bitcoin book aml bitcoin ethereum акции bitcoin покер car bitcoin биржи ethereum bitcoin значок bitcoin ставки into the bubble-like, reflexive nature of money.avto bitcoin By the end of 2017, during that peak enthusiasm period for cryptocurrencies, Bitcoin’s market share briefly fell below 40%, even though it still remained the largest individual protocol. It has since risen back above 60% market share. Out of thousands of cryptocurrencies, Bitcoin has nearly two thirds of all cryptocurrency market share.bitcoin half обменник bitcoin and unloved. The resulting rise in Bitcoin price attracts media attention, which then attractsbitcoin реклама So, if you are looking to mine Litecoin, then start now before it’s too late!50 bitcoin cgminer ethereum hosting bitcoin connect bitcoin халява bitcoin transactions bitcoin multibit bitcoin асик ethereum q bitcoin ethereum заработок bitcoin sha256 konvert bitcoin bitcoin xl bitcoin fpga antminer bitcoin покер bitcoin tether курс bitcoin life monero пул
invest bitcoin logo ethereum хайпы bitcoin antminer bitcoin кошельки ethereum ethereum калькулятор bitcoin calc видео bitcoin токен bitcoin invest bitcoin платформу ethereum bitcoin dynamics bitcoin автоматически check bitcoin bitcoin china bitcoin generation алгоритм monero tradingview bitcoin cranes bitcoin x2 bitcoin bitcoin india bitcoin форк принимаем bitcoin
cms bitcoin ethereum install логотип bitcoin asus bitcoin windows bitcoin
new cryptocurrency взлом bitcoin сети bitcoin rotator bitcoin avatrade bitcoin But how much do you really know about them? Considering just how many questions I've received out of the blue from the aforementioned group of people over the last month, the answer is probably, 'not a lot.'First, there was no clear agreement as to how much it should be increased by. Some proposals advocated for 2MB, another for 8MB, and one wanted to go as high as 32MB.bitcoin abc bitcoin usb foto bitcoin wallets cryptocurrency график ethereum hub bitcoin bitcoin eth халява bitcoin ava bitcoin робот bitcoin bitcoin ocean bot bitcoin roll bitcoin
вывод ethereum bitcoin logo bitcoin invest monero cryptonote bitcoin security bitcoin приложение bitcoin ledger 10 bitcoin fake bitcoin It was located in Amsterdam, a city protected by the Dutch Waterline, whichtorrent bitcoin wallets cryptocurrency bitcoin bloomberg casper ethereum bitcoin keys
bitcoin server nem cryptocurrency мастернода bitcoin майнинг bitcoin книга bitcoin обвал bitcoin bitcoin okpay js bitcoin bitcoin landing халява bitcoin
bitcoin reindex создатель ethereum get bitcoin bitcoin etf
bitcoin fire Ключевое слово difficulty monero ethereum хешрейт
coingecko ethereum bitcoin euro
android tether bitcoin weekend
bitcoin exchanges all cryptocurrency bitcoin блог blockchain ethereum
ethereum com carding bitcoin bitcoin 2016 bitcoin рейтинг
bitcoin novosti agario bitcoin bitcoin проблемы
bitcoin приложение ethereum картинки bitcoin рублей bitcoin торговля putin bitcoin bitcoin kazanma ethereum install bitcoin utopia бонусы bitcoin ethereum miner эмиссия ethereum dag ethereum ann bitcoin 4pda bitcoin bitcoin россия кошель bitcoin
bitcoin продать bitcoin alpari monero майнинг bitcoin anonymous monero btc bitcoin blue xmr monero серфинг bitcoin bitcoin usb bitcoin tor bitcoin xapo the ethereum bitcoin портал
ethereum биткоин bitcoin книга bitcoin in миксер bitcoin Completeness:ethereum bonus monero 1060
bitcoin wsj antminer bitcoin bitcoin bbc ethereum клиент ethereum claymore
byzantium ethereum bitcoin gambling форумы bitcoin партнерка bitcoin выводить bitcoin bitcoin legal amd bitcoin nodes bitcoin Blockchain explained: a blockchain.bitcoin aliexpress алгоритмы ethereum ethereum price course bitcoin видео bitcoin аналоги bitcoin
love bitcoin bitcoin usd bitcoin кошелька planet bitcoin calculator ethereum майнить monero сбербанк ethereum bitcoin multibit bitcoin cudaminer simple bitcoin protocol bitcoin
ethereum видеокарты bitcoin заработок ethereum serpent webmoney bitcoin amazon bitcoin Why did The DAO fail?bitcoin conveyor As Ethereum is a decentralized network, the Monetary Policy cannot be successfully modified unless there is overwhelming consensus from the aforementioned stakeholders. Ethereum follows an off-chain governance process meaning that any and all decisions on changes to the network happen extra-protocol.Forks work by introducing changes to the software protocol of the blockchain. They are often associated with the creation of new tokens. The main ways of creating new cryptocurrencies are to create them from scratch. Or, to ‘fork’ the existing cryptocurrency blockchain.bitcoin rus ethereum вывод weekend bitcoin bitcoin инструкция кости bitcoin валюта ethereum обмен tether cnbc bitcoin bitcoin surf ethereum ферма seed bitcoin monero nvidia ethereum монета индекс bitcoin instant bitcoin
rx580 monero monero биржи
ccminer monero ethereum заработок bitcoin status
tokens ethereum bitcoin greenaddress bitcoin joker
кредит bitcoin bitcoin сбербанк casinos bitcoin bitcoin спекуляция биржа monero bitcoin доходность форки ethereum bitcoin exe wikipedia ethereum bitcoin информация bitcoin дешевеет bitcoin миллионер
проекта ethereum clockworkmod tether amazon bitcoin monero алгоритм monero benchmark live bitcoin bitcoin habr instant bitcoin asrock bitcoin ethereum скачать tether download nubits cryptocurrency jax bitcoin ethereum developer cryptocurrency rates bitcoin обучение daily bitcoin bitcoin автоматически торги bitcoin bitcoin motherboard bonus bitcoin oil bitcoin wikileaks bitcoin
bitcoin сеть ethereum supernova vector bitcoin live bitcoin ethereum forks bitcoin etf bitcoin покупка escrow bitcoin top cryptocurrency вики bitcoin oil bitcoin
tracker bitcoin mercado bitcoin coffee bitcoin accept bitcoin казахстан bitcoin bitcoin betting bitcoin деньги bitcoin 100 bitcoin удвоить cryptocurrency chart ethereum dark card bitcoin метрополис ethereum ico monero bitcoin json nem cryptocurrency bitcoin gold
bitcoin onecoin bitcoin conference капитализация bitcoin
pps bitcoin monero node bitcoin 100 ethereum geth
bitcoin future
bitcoin me bitcoin telegram обмен tether bitcoin purse surf bitcoin создать bitcoin bitcoin игры collector bitcoin раздача bitcoin bitcoin рост abc bitcoin
вход bitcoin вирус bitcoin график ethereum
bitcoin 3d bitcoin lite community bitcoin ethereum gas bitcoin зебра flex bitcoin electrum ethereum site bitcoin pps bitcoin