Ethereum State Transition Function
Ether state transition
The Ethereum state transition function, APPLY(S,TX) -> S' can be defined as follows:
Check if the transaction is well-formed (ie. has the right number of values), the signature is valid, and the nonce matches the nonce in the sender's account. If not, return an error.
Calculate the transaction fee as STARTGAS * GASPRICE, and determine the sending address from the signature. Subtract the fee from the sender's account balance and increment the sender's nonce. If there is not enough balance to spend, return an error.
Initialize GAS = STARTGAS, and take off a certain quantity of gas per byte to pay for the bytes in the transaction.
Transfer the transaction value from the sender's account to the receiving account. If the receiving account does not yet exist, create it. If the receiving account is a contract, run the contract's code either to completion or until the execution runs out of gas.
If the value transfer failed because the sender did not have enough money, or the code execution ran out of gas, revert all state changes except the payment of the fees, and add the fees to the miner's account.
Otherwise, refund the fees for all remaining gas to the sender, and send the fees paid for gas consumed to the miner.
For example, suppose that the contract's code is:
if !self.storage[calldataload(0)]:
self.storage[calldataload(0)] = calldataload(32)
Note that in reality the contract code is written in the low-level EVM code; this example is written in Serpent, one of our high-level languages, for clarity, and can be compiled down to EVM code. Suppose that the contract's storage starts off empty, and a transaction is sent with 10 ether value, 2000 gas, 0.001 ether gasprice, and 64 bytes of data, with bytes 0-31 representing the number 2 and bytes 32-63 representing the string CHARLIE.fn. 6 The process for the state transition function in this case is as follows:
Check that the transaction is valid and well formed.
Check that the transaction sender has at least 2000 * 0.001 = 2 ether. If it is, then subtract 2 ether from the sender's account.
Initialize gas = 2000; assuming the transaction is 170 bytes long and the byte-fee is 5, subtract 850 so that there is 1150 gas left.
Subtract 10 more ether from the sender's account, and add it to the contract's account.
Run the code. In this case, this is simple: it checks if the contract's storage at index 2 is used, notices that it is not, and so it sets the storage at index 2 to the value CHARLIE. Suppose this takes 187 gas, so the remaining amount of gas is 1150 - 187 = 963
Add 963 * 0.001 = 0.963 ether back to the sender's account, and return the resulting state.
If there was no contract at the receiving end of the transaction, then the total transaction fee would simply be equal to the provided GASPRICE multiplied by the length of the transaction in bytes, and the data sent alongside the transaction would be irrelevant.
Note that messages work equivalently to transactions in terms of reverts: if a message execution runs out of gas, then that message's execution, and all other executions triggered by that execution, revert, but parent executions do not need to revert. This means that it is "safe" for a contract to call another contract, as if A calls B with G gas then A's execution is guaranteed to lose at most G gas. Finally, note that there is an opcode, CREATE, that creates a contract; its execution mechanics are generally similar to CALL, with the exception that the output of the execution determines the code of a newly created contract.
Code Execution
The code in Ethereum contracts is written in a low-level, stack-based bytecode language, referred to as "Ethereum virtual machine code" or "EVM code". The code consists of a series of bytes, where each byte represents an operation. In general, code execution is an infinite loop that consists of repeatedly carrying out the operation at the current program counter (which begins at zero) and then incrementing the program counter by one, until the end of the code is reached or an error or STOP or RETURN instruction is detected. The operations have access to three types of space in which to store data:
The stack, a last-in-first-out container to which values can be pushed and popped
Memory, an infinitely expandable byte array
The contract's long-term storage, a key/value store. Unlike stack and memory, which reset after computation ends, storage persists for the long term.
The code can also access the value, sender and data of the incoming message, as well as block header data, and the code can also return a byte array of data as an output.
The formal execution model of EVM code is surprisingly simple. While the Ethereum virtual machine is running, its full computational state can be defined by the tuple (block_state, transaction, message, code, memory, stack, pc, gas), where block_state is the global state containing all accounts and includes balances and storage. At the start of every round of execution, the current instruction is found by taking the pc-th byte of code (or 0 if pc >= len(code)), and each instruction has its own definition in terms of how it affects the tuple. For example, ADD pops two items off the stack and pushes their sum, reduces gas by 1 and increments pc by 1, and SSTORE pops the top two items off the stack and inserts the second item into the contract's storage at the index specified by the first item. Although there are many ways to optimize Ethereum virtual machine execution via just-in-time compilation, a basic implementation of Ethereum can be done in a few hundred lines of code.
Blockchain and Mining
Ethereum apply block diagram
The Ethereum blockchain is in many ways similar to the Bitcoin blockchain, although it does have some differences. The main difference between Ethereum and Bitcoin with regard to the blockchain architecture is that, unlike Bitcoin(which only contains a copy of the transaction list), Ethereum blocks contain a copy of both the transaction list and the most recent state. Aside from that, two other values, the block number and the difficulty, are also stored in the block. The basic block validation algorithm in Ethereum is as follows:
Check if the previous block referenced exists and is valid.
Check that the timestamp of the block is greater than that of the referenced previous block and less than 15 minutes into the future
Check that the block number, difficulty, transaction root, uncle root and gas limit (various low-level Ethereum-specific concepts) are valid.
Check that the proof of work on the block is valid.
Let S be the state at the end of the previous block.
Let TX be the block's transaction list, with n transactions. For all i in 0...n-1, set S = APPLY(S,TX). If any application returns an error, or if the total gas consumed in the block up until this point exceeds the GASLIMIT, return an error.
Let S_FINAL be S, but adding the block reward paid to the miner.
Check if the Merkle tree root of the state S_FINAL is equal to the final state root provided in the block header. If it is, the block is valid; otherwise, it is not valid.
The approach may seem highly inefficient at first glance, because it needs to store the entire state with each block, but in reality efficiency should be comparable to that of Bitcoin. The reason is that the state is stored in the tree structure, and after every block only a small part of the tree needs to be changed. Thus, in general, between two adjacent blocks the vast majority of the tree should be the same, and therefore the data can be stored once and referenced twice using pointers (ie. hashes of subtrees). A special kind of tree known as a "Patricia tree" is used to accomplish this, including a modification to the Merkle tree concept that allows for nodes to be inserted and deleted, and not just changed, efficiently. Additionally, because all of the state information is part of the last block, there is no need to store the entire blockchain history - a strategy which, if it could be applied to Bitcoin, can be calculated to provide 5-20x savings in space.
A commonly asked question is "where" contract code is executed, in terms of physical hardware. This has a simple answer: the process of executing contract code is part of the definition of the state transition function, which is part of the block validation algorithm, so if a transaction is added into block B the code execution spawned by that transaction will be executed by all nodes, now and in the future, that download and validate block B.
Applications
In general, there are three types of applications on top of Ethereum. The first category is financial applications, providing users with more powerful ways of managing and entering into contracts using their money. This includes sub-currencies, financial derivatives, hedging contracts, savings wallets, wills, and ultimately even some classes of full-scale employment contracts. The second category is semi-financial applications, where money is involved but there is also a heavy non-monetary side to what is being done; a perfect example is self-enforcing bounties for solutions to computational problems. Finally, there are applications such as online voting and decentralized governance that are not financial at all.
Token Systems
On-blockchain token systems have many applications ranging from sub-currencies representing assets such as USD or gold to company stocks, individual tokens representing smart property, secure unforgeable coupons, and even token systems with no ties to conventional value at all, used as point systems for incentivization. Token systems are surprisingly easy to implement in Ethereum. The key point to understand is that a currency, or token system, fundamentally is a database with one operation: subtract X units from A and give X units to B, with the provision that (1) A had at least X units before the transaction and (2) the transaction is approved by A. All that it takes to implement a token system is to implement this logic into a contract.
The basic code for implementing a token system in Serpent looks as follows:
def send(to, value):
if self.storage[msg.sender] >= value:
self.storage[msg.sender] = self.storage[msg.sender] - value
self.storage = self.storage + value
This is essentially a literal implementation of the "banking system" state transition function described further above in this document. A few extra lines of code need to be added to provide for the initial step of distributing the currency units in the first place and a few other edge cases, and ideally a function would be added to let other contracts query for the balance of an address. But that's all there is to it. Theoretically, Ethereum-based token systems acting as sub-currencies can potentially include another important feature that on-chain Bitcoin-based meta-currencies lack: the ability to pay transaction fees directly in that currency. The way this would be implemented is that the contract would maintain an ether balance with which it would refund ether used to pay fees to the sender, and it would refill this balance by collecting the internal currency units that it takes in fees and reselling them in a constant running auction. Users would thus need to "activate" their accounts with ether, but once the ether is there it would be reusable because the contract would refund it each time.
bitcoin динамика In networked environments (like the world of cryptocurrencies), new developments tend to follow a power law distribution; there are a few clear,A Brief History of Cryptocurrencybitcoin apk bitcoin bbc
bitcoin fpga
bitcoin символ bitcoin торрент skrill bitcoin 1 bitcoin bitcoin теханализ course bitcoin bitcoin алматы hashrate ethereum ethereum miner bitcoin scripting mine ethereum vps bitcoin bitcoin take ethereum ферма
homestead ethereum вклады bitcoin network bitcoin These benefits make Litecoin a great alternative for sending and receiving funds. So, now that you can answer the question 'what is Litecoin?', let’s find out how the technology works!Information on a Blockchain network is not controlled by a centralized authority, unlike modern financial institutions. The participants of the network maintain the data, and they hold the democratic authority to approve any transaction which can happen on a Blockchain network. Therefore, a typical Blockchain network is a public Blockchain.bitcoin github
bitcoin protocol портал bitcoin
андроид bitcoin bitcoin перспективы bitcoin analysis bitcoin main bitcoin москва bitrix bitcoin bitcoin оплатить bitcoin ваучер bitcoin youtube word bitcoin microsoft ethereum bitcoin fees accepts bitcoin обновление ethereum bitcoin buying cubits bitcoin In other words, decentralization and scalability are currently at odds, but developers are hunting for ways around this.Litecoin is a lot like Bitcoin but its transactions are processed four times faster. Litecoin mining is easier than Bitcoin mining, so users with less powerful computers can become miners.bitcoin usd
monero pro bitcoin machine bitcoin криптовалюта порт bitcoin сбербанк bitcoin торги bitcoin зарабатывать bitcoin get bitcoin cryptocurrency calendar
обвал ethereum
bitcoin фарминг rise cryptocurrency
bitcoin футболка Ethereum founder Joe Lubin explains what it is %trump2% why it mattersэпоха ethereum ethereum claymore автоматический bitcoin antminer bitcoin карты bitcoin In the years since Bitcoin launched, there have been numerous instances in which disagreements between factions of miners and developers prompted large-scale splits of the cryptocurrency community. In some of these cases, groups of Bitcoin users and miners have changed the protocol of the Bitcoin network itself. This process is known 'forking' and usually results in the creation of a new type of Bitcoin with a new name. This split can be a 'hard fork,' in which a new coin shares transaction history with Bitcoin up until a decisive split point, at which point a new token is created. Examples of cryptocurrencies that have been created as a result of hard forks include Bitcoin Cash (created in August 2017), Bitcoin Gold (created in October 2017) and Bitcoin SV (created in November 2017). A 'soft fork' is a change to protocol which is still compatible with the previous system rules. Bitcoin soft forks have increased the total size of blocks, as an example.How Bitcoin WorksCase in point: In October of 2020, PayPal launched a new service that made it possible for their account holders to buy, sell, or hold cryptocurrency, or to use it to buy stuff at 26 million different merchants.bitcoin laundering change bitcoin airbit bitcoin ecdsa bitcoin claymore monero bitcoin switzerland bitcoin poloniex bitcoin redex monero gui phoenix bitcoin bitcoin cryptocurrency bitcoin minergate nvidia bitcoin reward bitcoin опционы bitcoin bitcoin fees выводить bitcoin символ bitcoin earnings bitcoin bitcoin hash boxbit bitcoin bitcoin майнинг abi ethereum bitcoin кредит Most people trace the beginnings of blockchain back to Bitcoin and the Bitcoin Whitepaper of 2008. But many elements of blockchain technology actually precede Satoshi Nakamoto’s outline for a Peer-to-Peer Electronic Cash System.bitcoin code курс bitcoin bitcoin заработать linux ethereum bitcoin zone
panda bitcoin
сложность monero bitcoin dice пул monero bitcoin блоки pump bitcoin контракты ethereum сборщик bitcoin boxbit bitcoin bitcoin сбербанк
Given that critical ingredient, the hedging contract would look as follows:bitcoin сервера forecast bitcoin frog bitcoin bitcoin coin bitcoin сайт satoshi bitcoin что bitcoin bitcoin count in bitcoin gek monero ethereum coin
monero купить ethereum investing gambling bitcoin mikrotik bitcoin bitcoin hacker bitcoin компьютер 100 bitcoin tether обменник bitcoin fpga bitcoin фото gadget bitcoin bitcoin io bitcoin расшифровка bitcoin cgminer bitcoin биржи bitcoin symbol start bitcoin bitcoin check Tax Treatment Lifts Volatilitycryptocurrency gold cryptocurrency forum bitcoin роботы
why cryptocurrency cz bitcoin love bitcoin pps bitcoin bitcoin machine
system bitcoin ethereum icon программа tether bitcoin ne bitcoin cgminer
remix ethereum casper ethereum bitcoin online remix ethereum ethereum usd ethereum хешрейт metropolis ethereum monero кошелек bitcoin прогноз bitcoin it production cryptocurrency windows bitcoin bitcoin adder bitcoin 15 satoshi bitcoin cryptocurrency charts bitcoin mixer tx bitcoin ethereum news monero asic get bitcoin tether ico ethereum заработок bitcoin puzzle bitcoin москва abi ethereum
bitcoin genesis bitcoin вывод bitcoin traffic monero windows bitcoin книга смысл bitcoin футболка bitcoin linux ethereum bitcoin приложение monero fr ethereum кошельки tp tether стоимость bitcoin bitcoin nonce p2pool bitcoin buying bitcoin
bitcoin loan ethereum вики ethereum torrent ethereum 1070 ethereum developer
bitcoin car flappy bitcoin bitcoin vizit escrow bitcoin ethereum coin
исходники bitcoin bitcoin 100 bitcoin фарм
bitcoin suisse bitcoin mixer капитализация bitcoin ethereum акции bitcoin safe и bitcoin wallets cryptocurrency алгоритм monero neo bitcoin bitcoin gambling bank bitcoin bitcoin knots форк bitcoin
iso bitcoin card bitcoin tether майнинг lurkmore bitcoin луна bitcoin обменники bitcoin bitcoin скрипт эпоха ethereum blogspot bitcoin список bitcoin moneypolo bitcoin antminer ethereum фонд ethereum ethereum dark monero xmr 100 bitcoin bitcoin китай planet bitcoin bitcoin бумажник monero fee copay bitcoin bitcoin кошелька live bitcoin coinmarketcap bitcoin
блок bitcoin bitcoin аналоги bitcoin информация cryptocurrency wallet local ethereum ethereum биткоин go ethereum bitcoin биткоин bitcoin бонусы 1080 ethereum капитализация bitcoin ethereum serpent wikipedia cryptocurrency
bitcoin аккаунт sgminer monero monero майнить видеокарты ethereum life bitcoin
кошельки ethereum 16 bitcoin
top cryptocurrency bitcoin tails monero стоимость torrent bitcoin rbc bitcoin tether provisioning bitcoin обозреватель обмен tether forum bitcoin 100 bitcoin bitcoin ishlash виталик ethereum динамика ethereum перспектива bitcoin bitcoin мошенники bitcoin create платформ ethereum tether приложение cryptocurrency price tether верификация bitcoin описание краны ethereum ротатор bitcoin world bitcoin all cryptocurrency forex bitcoin bitcoin это bitcoin мониторинг партнерка bitcoin
bitcoin car
bitcoin сложность сбербанк bitcoin
cryptocurrency arbitrage bitcoin gift 6000 bitcoin
byzantium ethereum ethereum кошельки bitcoin plugin порт bitcoin исходники bitcoin claymore monero обменники ethereum bitcoin вирус bitcoin purchase bitcoin swiss monero обменник Download: Certificate Management Checklist Essential 14 Point Free PDFWorst case scenario, what if this entity gets corrupted and malicious? If that happens then all the data that is inside the blockchain will be compromised.nova bitcoin bitcoin кредит bitcoin сети bitcoin презентация bitcoin gold wallets cryptocurrency ethereum code bitcoin car bitcoin bitcoin сделки ethereum 2017 bitcoin cny калькулятор bitcoin bitcoin spinner
bitcoin суть
bitcoin markets
bitcoin оплатить microsoft bitcoin course bitcoin bitcoin invest Blockchain explained: a chart.bitcoin spinner pay bitcoin video bitcoin проект bitcoin
micro bitcoin bitcoin tor bitcoin client bitcoin вебмани bitcoin википедия However, the problem with this design is that it is not really that scalable. Which is why a lot of new generation cryptocurrencies adopt a leader-based consensus mechanism. In EOS, Cardano, Neo, etc. the nodes elect leader nodes or 'supernodes' who are in charge of the consensus and overall network health. These cryptos are a lot faster but they are not the most decentralized of systems.Transaction linkabilityethereum transactions service bitcoin bitcoin china bitcoin microsoft биржи ethereum bitcoin робот bitcoin example bitcoin take ethereum майнить bitcoin вектор bitcoin server bitcoin demo ethereum coins bitcoin group bitcoin расчет ubuntu ethereum video bitcoin bitcoin rate ethereum акции bitcoin department зарабатывать bitcoin
bitcoin agario
bitcoin адрес развод bitcoin download bitcoin bitcoin get ethereum gold ethereum free зарабатывать bitcoin bitcoin chart alpari bitcoin tether chvrches film bitcoin invest bitcoin bitcoin зарабатывать calculator cryptocurrency maps bitcoin ads bitcoin gold cryptocurrency ethereum биткоин it bitcoin bitcoin исходники продам ethereum
bitcoin курс bitcoin часы bitcoin пополнение перевести bitcoin bitcoin minergate nonce bitcoin bloomberg bitcoin bitcoin сделки ethereum купить ethereum проблемы
bitcoin вебмани динамика ethereum bitcoin основы ethereum ethash of zero bits required and can be verified by executing a single hash.ethereum tokens bitcoin обсуждение теханализ bitcoin tether криптовалюта tracker bitcoin логотип bitcoin bitcoin flip купить ethereum cardano cryptocurrency
okpay bitcoin форки bitcoin dwarfpool monero sell ethereum bitcoin earnings bitcoin основы bitcoin перспектива bitcoin habrahabr ropsten ethereum ethereum pos
bitcoin казахстан registration bitcoin bitcoin сервисы bitcoin market r bitcoin bitcoin net bitcoin заработать bye bitcoin google bitcoin tradingview bitcoin btc ethereum ethereum продам machine bitcoin bitcoin 2018 service bitcoin инвестирование bitcoin
50 bitcoin теханализ bitcoin bitcoin описание фермы bitcoin reddit bitcoin
bitcoin настройка bitcoin services dance bitcoin bitcoin maps bitcoin weekly casinos bitcoin bitcoin cache bitcoin биржа hashrate bitcoin bitcoin aliexpress gasPrice: the number of Wei that the sender is willing to pay per unit of gas required to execute the transaction.bitcoin red The community can be a powerful thing to surround yourself with while learning how to create a cryptocurrency. You’ll also need a place in which your community can talk to one another and ask you questions. The most popular app to use for this is Telegram. It is an instant messaging app, like WhatsApp or Facebook Messenger. However, it is known for its security and has become a very trusted, favored app in the crypto world.bitcoin buy обвал bitcoin bitcoin store monero wallet bitcoin сайты
koshelek bitcoin account bitcoin bitcoin скрипт
monero ico ethereum rotator окупаемость bitcoin
ethereum android bitcoin change майнить bitcoin bitcoin ethereum bitcoin download bitcoin 50000 капитализация bitcoin tor bitcoin
ethereum биржа bitcoin вконтакте pools bitcoin mining ethereum bitcoin easy
wikileaks bitcoin freeman bitcoin china cryptocurrency bitcoin fire byzantium ethereum ethereum кошельки bitcoin it ethereum network alipay bitcoin ethereum курсы forex bitcoin dog bitcoin minergate monero bitcoin github bitcoin блог ethereum прибыльность ethereum хешрейт blockchain ethereum bitcoin раздача bitcoin wordpress казино ethereum сделки bitcoin avatrade bitcoin bitcoin quotes
cryptocurrency analytics webmoney bitcoin криптовалюты bitcoin оплатить bitcoin ccminer monero
bitcoin earn bitcoin media tp tether mail bitcoin tether apk avatrade bitcoin jax bitcoin хабрахабр bitcoin bitcoin youtube The biggest change compared to GPU that Field Programmable Gate Array has brought is the reduction in consumed power which decreased 5 times while giving a 30% boost in mining efficiency. This is the time when big players started joining the Bitcoin game.The now: ASICThe final (at least for now) method of mining Bitcoins is using the Application-Specific Integrated Circuit.cryptocurrency trading bitcoin 3 игра bitcoin x2 bitcoin ethereum получить tether bootstrap primedice bitcoin
dash cryptocurrency bitcoin форекс новости bitcoin bitcoin visa
monero майнер кошелька bitcoin
bitcoin project difficulty ethereum faucet ethereum world bitcoin rotator bitcoin bitcoin brokers bitcoin spinner платформы ethereum конференция bitcoin bitcoin рубль bitcoin super hourly bitcoin bitcoin приложение сервера bitcoin кошель bitcoin cubits bitcoin bitcoin вконтакте blender bitcoin clame bitcoin bitcoin matrix обмен bitcoin index bitcoin bitcoin надежность bitcoin in abc bitcoin
monero difficulty bitcoin qazanmaq bitcoin poloniex bitcoin currency bitcoin rub ethereum 1070 bitcoin видеокарты importprivkey bitcoin ethereum calc and there is no central point of failure.исходники bitcoin