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.
monero minergate While Ripple works in a bit more complicated way, the above example explains its basic workings. The Ripple system scores better than the bitcoin network for its lower processing times and lower transaction charges.5 6 On the other hand, BTC is generally more widespread and better known than XRP, giving it the advantage in other ways.1phoenix bitcoin Issues with dataethereum алгоритмы Have you ever had a financial advisor (or maybe even a parent) tell you that you need to make your money grow? This idea has been so hardwired in the minds of hard-working people all over the world that it has become practically second nature to the very idea of work.However, it is important to remember that you will need to invest in the mining equipment on your own and pay for all of the required electricity on your own too. This can become really expensive and if you can’t afford to do it, you may need to consider another option.bitcoin bcc sgminer monero free bitcoin
crococoin bitcoin
bitcoin книга криптовалюта tether agario bitcoin скрипты bitcoin
stats ethereum In the first half of 2018, Monero was used in 44% of cryptocurrency ransomware attacks.blog bitcoin рост bitcoin bitcoin maps использование bitcoin сделки bitcoin пример bitcoin баланс bitcoin bitcoin loan lurkmore bitcoin tether usd fast bitcoin bitcoin knots ethereum логотип connect bitcoin bitcoin сатоши bitcoin update dance bitcoin майнер ethereum Economic Argument 2iphone bitcoin tether usd dollar bitcoin bitcoin apple
bitcoin media dog bitcoin world bitcoin bitcoin код 5ASICs and mining poolsbitcoin bio torrent bitcoin bitcoin реклама
bitcoin валюта bitcoin scam стоимость monero ethereum go cryptocurrency tech конференция bitcoin bitcoin s atm bitcoin bitcoin instagram виталик ethereum bitcoin блокчейн skrill bitcoin бот bitcoin сбербанк bitcoin
продам ethereum bitcoin trade bitcoin coinwarz ethereum валюта bitcoin prosto bitcoin рублей зебра bitcoin fast bitcoin cryptocurrency trading lazy bitcoin bitcoin neteller bitcoin видеокарты MV = PTdoubler bitcoin
ethereum node ninjatrader bitcoin платформ ethereum bitcoin rpg bitcoin android серфинг bitcoin ethereum blockchain конвертер monero bitcoin зарабатывать bitcoin bow bitcoin конверт blockchain ethereum деньги bitcoin bitcoin prosto coinbase ethereum cryptocurrency charts
bitcoin org генераторы bitcoin ethereum forum bitcoin hacker fx bitcoin bitcoin people bitcoin registration торрент bitcoin баланс bitcoin краны monero ethereum project лотереи bitcoin 16 bitcoin кран bitcoin casper ethereum monero алгоритм live bitcoin lazy bitcoin bitcoin earn usb tether ethereum ubuntu attack bitcoin hit bitcoin bitcoin bloomberg bitcoin взлом bitcoin fire bitcoin депозит china cryptocurrency Ring Confidential Transactions, or RingCT, also enable hiding the amount of a transaction. After achieving success in hiding the identities of senders and receivers, the RingCT functionality was introduced in January 2017 and is mandatory for all transactions executed on the Monero network.4bitcoin биржа nanopool ethereum bitcoin marketplace bitcoin пополнить bitcoin продам ico bitcoin bitcoin лохотрон
ethereum пулы mini bitcoin ethereum pools ropsten ethereum Ключевое слово programming bitcoin mine monero акции ethereum talk bitcoin A bitcoin holds a simple data ledger file called a blockchain. Each blockchain is unique to each user and the user's personal bitcoin wallet.bitcoin neteller golang bitcoin bitcoin nasdaq bitcoin ваучер torrent bitcoin прогнозы ethereum block bitcoin bitcoin investing bitcoin billionaire bitcoin шахта bitcoin drip bitcoin ios credit bitcoin bitcoin видеокарты bitcoin q
bitcoin лотерея code bitcoin preev bitcoin ethereum dag cryptocurrency reddit ethereum supernova
bitcoin media ad bitcoin bitcoin q bitcoin таблица казино bitcoin bitcoin настройка half bitcoin bitcoin mt4 bitcoin hd
вход bitcoin bitcoin автоматически usa bitcoin блок bitcoin bitcoin блокчейн bitcoin kz
сети bitcoin bitcoin график bitcoin etf bitcoin background bitcoin analytics bitcoin euro zcash bitcoin bitcoin покупка bitcoin магазины фото bitcoin ethereum client 600 bitcoin sberbank bitcoin 2018 bitcoin ethereum gas bonus bitcoin reklama bitcoin tether скачать падение ethereum ads bitcoin bitcoin skrill bitcoin demo ethereum faucet nya bitcoin конференция bitcoin bitcoin puzzle
is bitcoin bitcoin sberbank
forum bitcoin abc bitcoin bitcoin accelerator bitcoin пулы bitcoin пополнить bitcoin телефон криптовалюты bitcoin bitcoin регистрация claymore monero
wirex bitcoin bitcoin yen flex bitcoin россия bitcoin сигналы bitcoin masternode bitcoin окупаемость bitcoin monero ico bitcoin 4pda монет bitcoin ethereum api
динамика ethereum monero usd bitcoin london 4000 bitcoin bitcoin сегодня monero js accepts bitcoin
usb tether халява bitcoin equihash bitcoin auto bitcoin bitcoin терминалы bitcoin win The public-keys-as-identities idea is also seen in b-money and bit gold, the two precursor essays to bitcoin discussed earlier. However, much of the work that built on Chaum's foundation, as well as Chaum's own later work on ecash, moved away from this idea. The cypherpunks were keenly interested in privacy-preserving communication and commerce, and they embraced pseudonyms, which they called nyms. But to them, nyms were not mere cryptographic identities (that is, public keys), but rather, usually email addresses that were linked to public keys. Similarly, Ian Goldberg's dissertation, which became the basis of much future work on anonymous communication, recognizes Chaum's idea but suggests that nyms should be human-memorable nicknames with certificates to bind them.20 Thus Bitcoin proved to be the most successful instantiation of Chaum's idea.продам bitcoin bitcoin rbc пример bitcoin bitcoin calculator график monero
bitcoin покупка bitcoin russia bitcoin map bitcoin реклама bitcoin автоматический siiz bitcoin конвертер bitcoin case bitcoin credit bitcoin bitcoin euro bitcoin maining bitcoin клиент
адреса bitcoin 1. It is decentralizedmonero форк ethereum transactions best bitcoin bank cryptocurrency ethereum addresses 33 bitcoin alpha bitcoin покупка bitcoin coinmarketcap bitcoin bitcoin лайткоин капитализация bitcoin
bitcoin collector bitcoin birds bitcoin заработок ios bitcoin создать bitcoin testnet bitcoin вход bitcoin bitcoin 2048 bitcoin кранов краны monero monero gui anomayzer bitcoin bitcoin code
token bitcoin ethereum news bitcoin carding bitcoin payeer bitcoin переводчик scrypt bitcoin antminer bitcoin bitcoin msigna bitcoin neteller ethereum хардфорк bitcoin machine ethereum txid bitcoin clouding china bitcoin bitcoin project bitcoin мастернода alipay bitcoin cryptocurrency mining korbit bitcoin блог bitcoin bitcoin видеокарта monero пул bitcoin часы bitcoin кости вклады bitcoin
программа ethereum куплю ethereum
tether clockworkmod ethereum пул bitcoin koshelek currency bitcoin iso bitcoin bitcoin 1000 фермы bitcoin bitcoin авито основатель ethereum claim bitcoin bitcoin greenaddress bitcoin аккаунт bitcoin xapo математика bitcoin buy tether bitcoin trust vk bitcoin bitcoin pizza ethereum markets bitcoin boom bitcoin bazar bitcoin loan ethereum проекты
tether plugin bitcoin смесители monero asic bitcoin 4000 c bitcoin mooning bitcoin майнинг bitcoin king bitcoin ethereum swarm iso bitcoin Building a ‘Coin’ vs. Building a ‘Token’jaxx bitcoin tether usdt credit bitcoin connect bitcoin деньги bitcoin
график monero значок bitcoin bitcoin mining bitcoin scam reklama bitcoin bitcoin system
ethereum github ethereum frontier bitcoin информация проект bitcoin Best Bitcoin mining hardware: Your top choices for choosing the best Bitcoin mining hardware for building the ultimate Bitcoin mining machine.This group agreement is also known as a 'consensus'. It occurs during the process of mining.цена ethereum bitcoin weekly Privacybitcoin games transactions bitcoin bitcoin выиграть bitcoin direct
monero новости
пример bitcoin картинки bitcoin usdt tether bitcoin кошелька credit bitcoin сборщик bitcoin ethereum clix видео bitcoin bitcoin loan reddit cryptocurrency bitcoin обменять loans bitcoin ферма bitcoin btc bitcoin bitcoin is шахта bitcoin casper ethereum bitcoin кран coinder bitcoin neo cryptocurrency bitcoin ukraine 6000 bitcoin депозит bitcoin
bitcoin футболка статистика ethereum bitcoin trend
серфинг bitcoin ethereum виталий bitcoin ann alpha bitcoin bitcoin wallet добыча bitcoin bitcoin gadget ico bitcoin знак bitcoin puzzle bitcoin bitcoin расшифровка bitcoin download poker bitcoin bitcoin обналичить
ethereum отзывы bitcoin book linux ethereum обмен bitcoin
bitcoin casascius reddit cryptocurrency bitcoin information bitcoin valet world bitcoin pplns monero bitcoin lurk joker bitcoin Ether: Ethereum's token, which is required to make transactions and execute smart contracts on Ethereum.ethereum addresses кости bitcoin
gain bitcoin bitcoin create bitcoin лого bitcoin invest all cryptocurrency coinder bitcoin
валюты bitcoin ethereum картинки
bitcoin tm bitcoin ставки tokens ethereum bitcoin коды bitcoin tm bitcoin server In the healthcare system, patients can connect to other hospitals and collect their medical data immediately. Apart from the delay, there are high data corruption chances since the information is stored in a physical memory system.bitcoin grant connect bitcoin bitcoin 1000 bitcoin серфинг курс bitcoin ethereum вики msigna bitcoin график monero bitcoin торрент pos ethereum покупка bitcoin genesis bitcoin bitcoin putin ethereum russia
all cryptocurrency bitcoin fun download tether bitcoin exchanges bitcoin список статистика ethereum bitcoin порт ethereum кошельки safe bitcoin ethereum история fox bitcoin r bitcoin bistler bitcoin платформ ethereum bitcoin background bitcoin деньги сервера bitcoin bitcoin database bitcoin блог bitcoin unlimited
alpari bitcoin 22 bitcoin bitcoin аналоги monero core map bitcoin bitcoin завести robot bitcoin widget bitcoin bitcoin развод bitcoin hardfork nicehash bitcoin tether верификация
click bitcoin