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 bitrix получить bitcoin сбор bitcoin bitcoin flip
пузырь bitcoin
bitcoin machine stake bitcoin algorithm ethereum
ethereum russia app bitcoin bitcoin подтверждение bitcoin china bitcoin earn bitcoin минфин bitcoin доходность биткоин bitcoin bitcoin криптовалюта
clicks bitcoin
bitcoin scripting bitcoin cc сайт ethereum bitcoin future ферма bitcoin ethereum статистика All things considered, staking on blockchains remains a dynamic part of the wider crypto and blockchain space.exchange ethereum bitcoin 999 bitcoin hosting cryptocurrency tech bitcoin blender
habrahabr bitcoin бонус bitcoin nicehash monero bitcoin hosting monero rub site bitcoin bitcoin weekly strategy bitcoin monero algorithm course bitcoin приложения bitcoin bitcoin store bitcoin people полевые bitcoin bitcoin checker index bitcoin stealer bitcoin bitcoin автосерфинг ethereum testnet ico ethereum flypool monero difficulty ethereum bitcoin flapper multiply bitcoin In April 2017, researchers highlighted three major threats to Monero users' privacy. The first relies on leveraging the ring signature size of zero, and ability to see the output amounts. The second, 'Leveraging Output Merging', involves tracking transactions where two outputs belong to the same user, such as when they send funds to themselves ('churning'). Finally, 'Temporal Analysis', shows that predicting the right output in a ring signature could potentially be easier than previously thought. The Monero development team responded that they had already addressed the first concern with the introduction of RingCTs in January 2017, as well as mandating a minimum size of ring signatures in March 2016.explorer ethereum nonce bitcoin gps tether putin bitcoin bot bitcoin ubuntu bitcoin bitcoin обменять bitcoin yandex запуск bitcoin enterprise ethereum tether io ubuntu ethereum
ethereum russia торговать bitcoin bitcoin plugin bitcoin mine legal bitcoin ethereum geth bitcoin отзывы accept bitcoin криптовалют ethereum магазины bitcoin bitcoin заработок habrahabr bitcoin обменять bitcoin oil bitcoin кран monero bitcoin настройка Highly secure. It is just a matter of securing your private key.Founded in 2009, PayStand aims to be a multi-payment gateway that eliminates merchant transaction fees, in part by supporting digital currency acceptance.bitcoin блок coin bitcoin
bitcoin agario bitcoin видеокарта bitcoin заработок bitcoin торги ethereum график ethereum chart credit bitcoin weekly bitcoin bitcoin обои strategy bitcoin case bitcoin bitcoin wallpaper валюты bitcoin bitcoin biz
bitcoin apk bitcoin video bitcoin school bitcoin count bitcoin word claim bitcoin Blockchains are not built from a new technology. They are built from a unique orchestration of three existing technologies.This article relies too much on references to primary sources. (August 2020)Traders who want to take on that risk should use only a locally regulated forex brokerage.Investing in Bitcoin IRAs: Reading Into the Pros and Consthose rules. If a node attempts to break a rule, all other nodes will reject its information. ProposedPool Miningcurrency bitcoin strategy bitcoin bitcoin кранов bitcoin favicon ava bitcoin
bitcoin теория bitcoin ann 600 bitcoin play bitcoin jaxx bitcoin bitcoin litecoin coinmarketcap bitcoin статистика ethereum bitcoin lion bitcoin рулетка
отзыв bitcoin статистика ethereum будущее bitcoin 50 bitcoin qiwi bitcoin rates bitcoin
rx580 monero maps bitcoin bitcoin серфинг
bitcoin kraken пулы bitcoin алгоритмы ethereum ethereum адрес big bitcoin ethereum telegram reddit bitcoin взлом bitcoin bitcoin skrill bitcoin ключи maps bitcoin bitcoin деньги регистрация bitcoin avatrade bitcoin bitcoin froggy bitcoin tools web3 ethereum bitcoin banking Basically, cryptocurrencies are entries about token in decentralized consensus-databases. They are called CRYPTOcurrencies because the consensus-keeping process is secured by strong cryptography. Cryptocurrencies are built on cryptography. They are not secured by people or by trust, but by math. It is more probable that an asteroid falls on your house than that a bitcoin address is compromised.wallet tether bitcoin котировки swarm ethereum динамика ethereum blocks bitcoin cryptocurrency arbitrage ethereum краны сеть ethereum blake bitcoin bitcoin приложения bitcoin pool bitcoin виджет mikrotik bitcoin free bitcoin cryptocurrency wallets Every transaction is mined (included in a new block and propagated for the first time) once, but executed and verified by every participant in the process of advancing the canonical EVM state. This highlights one of the central mantras of blockchain: Don’t trust, verifybitcoin развод fenix bitcoin
nicehash bitcoin bitcoin компания monero amd
bitcoin instagram converter bitcoin cronox bitcoin bitcoin update purchase bitcoin
moto bitcoin акции ethereum Ether is listed on exchanges under the ticker symbol ETH. The Greek uppercase Xi character (Ξ) is sometimes used for its currency symbol.Bitcoin is here to stay. As the very first cryptocurrency, it has opened the door to a new world of digital money and even more than digital money – digital value that knows (almost) no boundaries.логотип bitcoin bitcoin grafik Each of these platforms, in and of themselves, represents a significant innovation – taken together they make it possible to envision a world of finance that is open to anyone and offers financial services in a permissionless way.What is Bitcoin?ethereum создатель фри bitcoin bitcoin ira bitcoin скрипт bitcoin сервера msigna bitcoin bitcoin bloomberg bitcoin betting взломать bitcoin bitcoin server bitcoin metal bitcoin roll genesis bitcoin production cryptocurrency
скачать bitcoin майнинга bitcoin проблемы bitcoin In the case you prefer to buy Litecoin with cryptocurrencies, however, you do not own any cryptocurrency, then enter Coinbase, open an account, follow the instructions and you are ready to go.withdraw bitcoin
пополнить bitcoin bitcoin protocol bitcoin краны tether wifi cpa bitcoin bitcoin gambling ethereum info ethereum бутерин криптовалюту monero unconfirmed monero 22 bitcoin статистика ethereum bitcoin flapper bitcoin center hashrate bitcoin adbc bitcoin
bitcoin сделки bitcoin прогноз 99 bitcoin Litecoin mining is the processing of a block of transactions into the Litecoin blockchain.bitcoin russia банк bitcoin ethereum dao bitcoin отслеживание фарминг bitcoin отзывы ethereum
инструкция bitcoin monero mining халява bitcoin ethereum io local bitcoin 6000 bitcoin bitcoin авито автомат bitcoin bitcoin кости ethereum wiki
monero logo bitcoin инвестирование study history in the broad sense. As I read history books and papers, I’mbitcoin торговля bitcoin приложение bitcoin иконка bitcoin world программа tether bitcoin puzzle обмен tether bitcoin x2 tether обменник bitcoin описание utxo bitcoin secp256k1 ethereum boxbit bitcoin mikrotik bitcoin адрес ethereum bitcoin world программа bitcoin tether приложение
abi ethereum Basics of Bitcoin Walletsjoker bitcoin ethereum алгоритм bitcoin сервисы bitcoin бонус bitcoin crane cryptocurrency logo monero майнер 50 bitcoin bitcoin luxury To guarantee that a third-party, let's call her Eve, cannot spend other people's bitcoins by creating transactions in their names, Bitcoin uses public key cryptography to make and verify digital signatures. In this system, each person, such as Alice or Bob, has one or more addresses each with an associated pair of public and private keys that they may hold in a wallet. Only the user with the private key can sign a transaction to give some of their bitcoins to somebody else, but anyone can validate the signature using that user’s public key.bitcoin de купить ethereum ethereum котировки вход bitcoin bitcoin okpay cold bitcoin wallets cryptocurrency ethereum flypool ethereum пулы bitcoin habr q bitcoin