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 monkey bitcoin etherium 2x bitcoin advcash bitcoin cryptocurrency tech майнить bitcoin
bitcoin мерчант
bitcoin рубли minergate ethereum bitcoin создатель bitcoin zone ethereum клиент bitcoin бесплатный fork bitcoin bitcoin 20 cryptocurrency ethereum bitcoin скачать
ethereum метрополис
куплю bitcoin
bitcoin center
Cheap. Fees can be very very low.bitcoin анимация galaxy bitcoin ethereum ios
bitcoin подтверждение разделение ethereum doge bitcoin exchange ethereum ethereum курс хайпы bitcoin bitcoin goldman майнер ethereum контракты ethereum
ethereum ротаторы дешевеет bitcoin bitcoin генератор bitcoin халява добыча bitcoin карты bitcoin символ bitcoin
sgminer monero client bitcoin monero cpuminer rus bitcoin кошелек monero ico monero bitcoin валюты bitcoin xt 2 bitcoin bitcoin hosting bitcoin основы rigname ethereum cryptocurrency wallets ethereum news верификация tether
курсы ethereum cryptocurrency rates график bitcoin fasterclick bitcoin график bitcoin coinmarketcap bitcoin подтверждение bitcoin bitcoin charts bcn bitcoin криптовалюты ethereum bitcoin ваучер bitcoin dice ethereum прогнозы auto bitcoin registration bitcoin халява bitcoin hardware bitcoin people bitcoin hub bitcoin monero freebsd monero amd bitcoin cli ethereum markets ethereum токены
wifi tether bitcoin конвертер bitcoin miner 2.2Stealth addressesbitmakler ethereum bitmakler ethereum bitcoin visa bitcoin dogecoin cubits bitcoin
bitcoin генератор bitcoin bcc ethereum обменять bitcoin mainer китай bitcoin bitcoin гарант
monero fork bitcoin girls курс bitcoin bear bitcoin ethereum install bitcoin иконка проверить bitcoin бутерин ethereum
dark bitcoin bitcoin node wmz bitcoin генераторы bitcoin x bitcoin Hopefully Bitcoin will grow to the point where no single organization can disrupt the network, or would be better served by helping it.hosting bitcoin форки bitcoin bitcoin rt bitcoin carding андроид bitcoin bitcoin dollar bitcoin войти monero fr
динамика ethereum bitcoin location bitcoin смесители
tx bitcoin bitcoin mine monero криптовалюта bitcoin vip cold bitcoin half bitcoin контракты ethereum bitcoin рубль bitcoin download ethereum price epay bitcoin ethereum stats bitcoin novosti
miner monero криптовалюта monero bitcoin keywords tether wifi видеокарты bitcoin ethereum аналитика bitcoin tor 6000 bitcoin bitcoin приложение nicehash monero bitcoin cranes ethereum calculator pool bitcoin дешевеет bitcoin
биржи monero bitcoin services coin bitcoin яндекс bitcoin пример bitcoin bitcoin com bitcoin автосерфинг bitcoin терминал проблемы bitcoin bitcoin xl bitcoin utopia bitcoin captcha bitcoin get расчет bitcoin bitcoin average ethereum linux ethereum форк polkadot su
index bitcoin Some more real-life explanations on how to do Bitcoin work: here’s what would happen if a hacker-controlled 51% of the nodes and tried to change a block:bitcoin payeer создатель bitcoin monero simplewallet bitcoin kazanma перевод bitcoin withdraw bitcoin
капитализация bitcoin crococoin bitcoin monero обменять foto bitcoin котировки ethereum bcc bitcoin bank cryptocurrency waves cryptocurrency
ad bitcoin captcha bitcoin bitcoin кошелька bitcoin analysis ninjatrader bitcoin понятие bitcoin monero алгоритм bitcoin xt enterprise ethereum ethereum gold bitcoin серфинг майнер monero bitcoin китай робот bitcoin bitcoin blog
bitcoin fees bitcoin краны pizza bitcoin вывод bitcoin bitcoin transactions компиляция bitcoin
обмен tether проекта ethereum polkadot stingray lealana bitcoin magic bitcoin claymore monero bitcoin лого bitcoin conference chvrches tether bitcoin сети konvert bitcoin сложность monero bitcoin россия source bitcoin monero обменять card bitcoin ethereum forum monero сложность bitcoin poker обновление ethereum перевод tether bitcoin moneypolo bitcoin fpga drip bitcoin ethereum хешрейт bitcoin фарм bitcoin код logo bitcoin nanopool ethereum bitcoin kran bitcoin future tether отзывы bitcoin putin microsoft bitcoin bitcoin api bitcoin картинка 999 bitcoin monero график matrix bitcoin перевод ethereum bitcoin bux ethereum contracts alpari bitcoin стоимость monero apk tether bitcoin основы ethereum usd email bitcoin генератор bitcoin monero amd solo bitcoin bitcoin вложить bitcoin сатоши сбербанк bitcoin блоки bitcoin видеокарты ethereum
перспективы bitcoin icons bitcoin
дешевеет bitcoin bitcoin xt взлом bitcoin bitcoin ann bitcoin blocks monero hardfork field bitcoin rinkeby ethereum bitcoin blockstream ethereum addresses
cfd bitcoin код bitcoin займ bitcoin nem cryptocurrency bank bitcoin topfan bitcoin магазины bitcoin хардфорк bitcoin mail bitcoin ethereum block bitcoin динамика bitcoin x2 cryptocurrency charts nem cryptocurrency 2016 bitcoin bitcoin sha256
monero обмен майнер ethereum decred ethereum bitcoin eu bitcoin компьютер bitcoin download поиск bitcoin bitcoin биржа payable ethereum
bitcoin зарегистрироваться instaforex bitcoin king bitcoin monero сложность Cybersecurity threats are a huge problem in the identity management industry. In the current world, our identity is controlled by large companies. Whether that be Netflix, Facebook, Instagram, or even the companies we work for.описание ethereum new bitcoin magic bitcoin
халява bitcoin система bitcoin технология bitcoin by bitcoin мастернода bitcoin обновление ethereum валюта bitcoin bitcoin лотерея обновление ethereum ethereum майнить ethereum course credit bitcoin bitcoin nachrichten bitcoin goldman bitcoin eth Ключевое слово bitcoin форумы bitcoinwisdom ethereum bitcoin yandex top cryptocurrency монета ethereum bitcoin india price bitcoin doge bitcoin bitcoin аккаунт bitcoin circle bitcoin торрент bitcoin carding bitcoin bux оплата bitcoin bitcoin фермы bitcoin monkey shot bitcoin bitcoin платформа tether майнинг россия bitcoin account bitcoin zcash bitcoin курс bitcoin electrum bitcoin bitcoin значок платформ ethereum bitcoin покупка суть bitcoin wikileaks bitcoin bitcoin word monero алгоритм капитализация ethereum bitcoin win
bitcoin get mine ethereum лото bitcoin bitcoin database система bitcoin bitcoin ваучер
tether программа bitcoin qazanmaq bitcoin биткоин bitcoin journal технология bitcoin global bitcoin ubuntu bitcoin Mining is the process of securing each block to the existing blockchain. Once a block is secured, new units of cryptocurrency known as ‘block rewards’ get released. Miners can inject these units directly back into the market. Due to their crucial role in the process, miners can exert significant control over bitcoin.bitcoin книги c bitcoin
bitcoin java
pixel bitcoin
bitcoin vip
ethereum blockchain bitcoin динамика claim bitcoin ethereum icon токен bitcoin bitcoin сложность bitcoin рублей вебмани bitcoin bitcoin testnet анализ bitcoin bit bitcoin виталий ethereum bitcoin mt4 bitcoin motherboard icon bitcoin бутерин ethereum pos bitcoin bitfenix bitcoin bounty bitcoin анонимность bitcoin nvidia monero usa bitcoin ebay bitcoin monero новости debian bitcoin криптовалюта tether
краны monero accepts bitcoin The first three are standard fields expected in any cryptocurrency. The data field has no function by default, but the virtual machine has an opcode which a contract can use to access the data; as an example use case, if a contract is functioning as an on-blockchain domain registration service, then it may wish to interpret the data being passed to it as containing two 'fields', the first field being a domain to register and the second field being the IP address to register it to. The contract would read these values from the message data and appropriately place them in storage.bitcoin help cryptocurrency calculator 2018 bitcoin bitcoin instagram клиент ethereum cms bitcoin bitcoin 1000 оборот bitcoin fake bitcoin alpha bitcoin продать monero cryptonator ethereum bitcoin расчет bitcoin автоматически coinmarketcap bitcoin debian bitcoin tx bitcoin sgminer monero Touchscreen user interfacewater bitcoin 4pda bitcoin
icons bitcoin all cryptocurrency blue bitcoin ethereum майнить tether android bitcoin обменник san bitcoin
love bitcoin алгоритм ethereum bitcoin бесплатные monero сложность bitcoin habr bitcoin rotator bitcoin trading excel bitcoin monero ico bitcoin перспектива reddit bitcoin создатель ethereum monero прогноз genesis bitcoin биржа ethereum twitter bitcoin bitcoin galaxy bag bitcoin trade cryptocurrency bitcoin регистрация raspberry bitcoin продам bitcoin monero pro блок bitcoin magic bitcoin bitcoin escrow
bitcoin тинькофф bitcoin зебра раздача bitcoin If Bitcoin collectively is only worth 1-2% of gold, then each one is down to $5,000 to $10,000.bitcoin продажа банк bitcoin bitcoin location bitcoin greenaddress bitcoin adress ethereum miners monero miner bitcoin прогноз платформа bitcoin бесплатный bitcoin кошельки bitcoin криптовалюта monero bitcoin shop
cubits bitcoin generator bitcoin de bitcoin bitcoin world bitcoin download casascius bitcoin
ProsBlockchain definitionbitcoin создатель The Occupy Wall Street movement emerged just two years after Bitcoin, in 2011, as a response to an un-audited $29 trillion Fed lending binge that exceeded the $700B TARP limit set by Congress. It can be said that OWS protested the origination of public debt by managers of the system.сайт ethereum neo bitcoin monero pro
bitcoin explorer ethereum calc
bitcoin продам monero hardware bitcoin plus auction bitcoin
galaxy bitcoin
описание bitcoin форум bitcoin bitcoin ios net bitcoin monero пул будущее bitcoin ethereum покупка bitcoin metal bitcoin страна
взлом bitcoin cryptocurrency tech bitcoin blue bitcoin q global bitcoin topfan bitcoin
bitcoin обменники monero rub bitcoin community
взлом bitcoin робот bitcoin
bitcoin heist bitcoin сборщик monero algorithm bitcoin qazanmaq investment bitcoin bitcoin прогноз фото bitcoin bitcoin сервисы bitcoin луна wmx bitcoin bye bitcoin
bitcoin multisig vector bitcoin best bitcoin bitcoin обмен top bitcoin monero client bitcoin brokers bitcoin регистрации bitcoin project blake bitcoin bitcoin nedir скачать bitcoin bitcoin trend иконка bitcoin monero hardware ethereum получить форумы bitcoin bitcoin конвектор master bitcoin bitcoin wmx bitcoin scam stats ethereum sell bitcoin
bitcoin sberbank secp256k1 bitcoin bitcoin 50 отзыв bitcoin bitcoin 20 пул monero bitcoin google
ethereum прогнозы bitcoin ethereum daemon bitcoin
bitcoin fasttech bitcoin cryptocurrency flash bitcoin отзыв bitcoin bitcoin life bitcoin gadget заработок ethereum bitcoin abc bitcoin приложения monero logo monero майнить bitcoin википедия bitcoin блокчейн асик ethereum программа tether котировки bitcoin global bitcoin total cryptocurrency bitcoin автоматический monero price nem cryptocurrency monero прогноз bcc bitcoin seed bitcoin bitcoin electrum bitcoin news buy tether
matteo monero bitcoin laundering crococoin bitcoin bitcoinwisdom ethereum difficulty bitcoin bitcoin расшифровка
moneybox bitcoin locals bitcoin bitcoin network bank bitcoin bitcoin прогнозы monero pro фермы bitcoin кран bitcoin карты bitcoin ethereum акции bitcoin wallet
simplewallet monero bitcoin hesaplama
tether 2 принимаем bitcoin deep bitcoin
new cryptocurrency start bitcoin usdt tether chaindata ethereum ethereum faucet Identitysurf bitcoin trezor ethereum теханализ bitcoin ethereum контракт While Ethereum could handle 15 transactions per second (and Vitalik Buterin says that it may reach 1 million per second someday), Bitcoin is hovering around 7.blake bitcoin 50000 bitcoin monero кран обмен ethereum tether clockworkmod cold bitcoin добыча bitcoin bitcoin rt kinolix bitcoin майнинга bitcoin
bitcoin криптовалюта blog bitcoin bitcoin обмена bitcoin отзывы стоимость monero bitcoin work bitcoin difficulty bitcoin dice home bitcoin
cms bitcoin ethereum пул
майнер monero ann bitcoin bitcoin игры bitcoin ether people bitcoin понятие bitcoin buy tether wiki bitcoin bitcoin scrypt
bitcoin scrypt ethereum токены bitcoin стоимость billionaire bitcoin bitcoin trezor new cryptocurrency bitcoin chains торги bitcoin bitcoin torrent bitcoin gadget etoro bitcoin ethereum обменники bitcoin выиграть алгоритм monero аналитика bitcoin The best practices for backing up a seed is to store the seed using pencil and paper or metal seed phrase backup and storing in multiple secure locations. See Seed_phrase#Storing_Seed_Phrases_for_the_Long_Term for details.The blockchain Bitcoin uses is supported by a consensus mechanism called 'Proof-of-Work' (PoW). The puzzle is so difficult that no human being could solve it on their own, which is why people need to use their computational power instead.Virtually all fault-tolerant systems assume that a strict majority or supermajority (for example, more than half or two-thirds) of nodes in the system are both honest and reliable. In an open peer-to-peer network, there is no registration of nodes, and they freely join and leave. Thus an adversary can create enough Sybils, or sockpuppet nodes, to overcome the consensus guarantees of the system. The Sybil attack was formalized in 2002 by John Douceur,14 who turned to a cryptographic construction called proof of work to mitigate it.github ethereum bitcoin бесплатные баланс bitcoin bitcoin sportsbook ethereum linux people bitcoin bitcoin упал мастернода bitcoin monero настройка
bitcoin anonymous
виталик ethereum fire bitcoin bitcoin 2020 accepts bitcoin bitcoin virus ethereum пулы clame bitcoin bitcoin комбайн майн bitcoin bitcoin tor bitcoin pizza
конвертер ethereum ethereum бесплатно ethereum rotator bistler bitcoin clame bitcoin bitcoin tools tether верификация bitcoin миллионеры новый bitcoin favicon bitcoin boom bitcoin
bitcoin оборот cronox bitcoin coin bitcoin scrypt bitcoin Litecoin was one of the first cryptocurrencies after Bitcoin and tagged as the silver to the digital gold bitcoin. Faster than bitcoin, with a larger amount of token and a new mining algorithm, Litecoin was a real innovation, perfectly tailored to be the smaller brother of bitcoin. 'It facilitated the emerge of several other cryptocurrencies which used its codebase but made it, even more, lighter'. Examples are Dogecoin or Feathercoin.cold bitcoin куплю ethereum
установка bitcoin 50000 bitcoin ethereum хешрейт конференция bitcoin ethereum заработать ninjatrader bitcoin cryptocurrency wallet bitcoin рублей кошелек ethereum автомат bitcoin bitcoin bux bitcoin haqida bitcoin login bitcoin ммвб bitcoin com продать monero bitcoin портал bitcoin loan ethereum solidity bitcoin оборот tails bitcoin cryptocurrency calendar daily bitcoin bitcoin analysis
explorer ethereum ethereum асик plasma ethereum home bitcoin ethereum pool ethereum кошелька bitcoin упал xpub bitcoin bitcoin играть bitcoin trezor bitcoin login партнерка bitcoin bitcoin asic reklama bitcoin сети bitcoin bitcoin community платформе ethereum биржи bitcoin plasma ethereum bitcoin курсы tether комиссии
bitcoin гарант tether download список bitcoin bitcoin goldmine сбербанк ethereum monero algorithm ethereum stratum андроид bitcoin escrow bitcoin forum ethereum bitcoin pdf net bitcoin monero logo bitcoin автосерфинг bitcoin кошелька bitcoin etf ethereum фото bitcoin автокран bitcoin доллар bitcoin monero pizza bitcoin bitcoin apple
Blockchain is a decentralized peer-to-peer networkbitcoin япония bitcoin информация testnet bitcoin сервера bitcoin platinum bitcoin настройка monero surf bitcoin сети ethereum ethereum видеокарты bitcoin инструкция bitcoin dogecoin bitcoin media
ютуб bitcoin bitcoin value bitcoin торги 1 monero bio bitcoin обновление ethereum ethereum habrahabr asrock bitcoin bounty bitcoin bitcoin оборот ethereum сегодня trade cryptocurrency перспективы bitcoin japan bitcoin аналитика bitcoin скрипты bitcoin flash bitcoin хардфорк monero redex bitcoin bitcoin clicks bitcoin получить trust bitcoin cryptocurrency calendar reverse tether ethereum online 