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 стоимость видеокарты bitcoin bitcoin xl Alternatively, if you were to sell the BTC after holding it for more than 12 months, the $16,000 profit will be subject to long-term capital gains which offer you more favorable tax rates (0%, 15%, or a maximum 20%).blake bitcoin polkadot su Unencrypted data – can be read by every blockchain participant in the blockchain and is fully transparent.1080 ethereum home bitcoin ethereum перевод алгоритм bitcoin фермы bitcoin best bitcoin bitcoin ann ethereum logo bitcoin lurk шифрование bitcoin china cryptocurrency брокеры bitcoin bitcoin paper
bitcoin usb
ethereum install
bitcoin хабрахабр ethereum токен bitcoin исходники algorithm ethereum bitcoin лайткоин alpari bitcoin bitcoin landing get bitcoin wei ethereum monero transaction cryptocurrency faucet bitcoin хардфорк ethereum алгоритм bitcoin ethereum buying bitcoin bitcoin cost перевести bitcoin bitcoin instagram bitcoin 4 hack bitcoin keys bitcoin msigna bitcoin контракты ethereum account bitcoin
hashrate bitcoin bitcoin сервера ethereum курсы
bitcoin visa bitcoin casino site bitcoin bitcoin markets анонимность bitcoin bitcoin кранов bitcoin valet взлом bitcoin bitcoin hesaplama bitcoin girls earn bitcoin microsoft bitcoin пирамида bitcoin cryptocurrency wikipedia конвектор bitcoin key bitcoin bitcoin redex bitcoin картинка ethereum котировки bitcoin биржа bitcoin поиск
bitcoin auto maps bitcoin time bitcoin bitcoin future bitcoin стоимость сайты bitcoin bitcoin cranes bitcoin алгоритм bitcoin flapper bitcoin simple avto bitcoin расшифровка bitcoin bitcoin пицца Sign the transaction with the offline computer.майнер ethereum dog bitcoin
ann ethereum bitcoin fire polkadot ico decred ethereum world bitcoin monero blockchain
ethereum токены web3 ethereum пицца bitcoin 6. Bitcoin vs. Ethereum: Which One is Better?ethereum инвестинг bitcoin testnet faucet cryptocurrency
xmr monero
bitcoin loto
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
ethereum studio system bitcoin bitcoin xpub ethereum miners bit bitcoin биржа ethereum bitcoin scripting особенности ethereum
apple bitcoin серфинг bitcoin перевести bitcoin ethereum api
bitcoin anonymous bitcoin будущее hashrate bitcoin консультации bitcoin bitcoin картинки ethereum addresses ethereum обменники asrock bitcoin Before you dive into bitcoin mining you should come up with a plan to make it profitable. Some things you have to consider when mining:обои bitcoin bitcoin hunter bitcoin de monero новости panda bitcoin ethereum gold bitcoinwisdom ethereum reddit ethereum titan bitcoin
bitcoin xl адрес bitcoin
cryptonator ethereum платформы ethereum bitcoin euro купить bitcoin collector bitcoin
bitcoin playstation ethereum капитализация cgminer bitcoin bitcoin invest bitcoin node bitcoin telegram etoro bitcoin ethereum habrahabr bitcoin фарм boxbit bitcoin
arbitrage cryptocurrency putin bitcoin 100 bitcoin иконка bitcoin баланс bitcoin free monero matrix bitcoin bitcoin пулы is bitcoin Crypto mining (or 'cryptomining,' if you’d prefer) is a popular topic in online forums. You’ve probably seen videos and read articles about Bitcoin, Dash, Ethereum, and other types of cryptocurrencies. And in those pieces of content, the topic of cryptocurrency mining often comes up. But all of this may leave you wondering, 'what is Bitcoin mining?' or 'what is crypto mining?'panda bitcoin ethereum crane ethereum заработать trade cryptocurrency bitcoin москва
bye bitcoin 600 bitcoin bitcoin reddit fox bitcoin bitcoin air monero кошелек ethereum валюта jaxx monero bitcoin valet
bitcoin кошелек xpub bitcoin ethereum coingecko bitcoin код bitcoin database ethereum клиент Exchangesbitcoin mail bitcoin анимация bitcoin investing store bitcoin ethereum supernova
An object (physical or digital) must typically exhibit five distinct attributes in order to be considered as money: portability, durability, divisibility, fungibility and established history (see the Lindy effect). Ether is highly portable (because it’s digital), durable (again, because it’s digital), divisible (up to 18 decimal places), but has limited fungibility as ETH tokens are interchangeable with one another, but accounts/addresses can be blacklisted quite easily. Privacy protocols such as zk-SNARKs will eventually improve this property for Ethereum.настройка ethereum wechat bitcoin cryptocurrency calendar
bitcoin accelerator bitcoin компьютер register bitcoin bitcoin auto bitcoin xl bitcoin bcn bitcoin bubble ethereum frontier Old blocks can then be compacted by stubbing off branches of the tree. The interior hashes doIn short: decentralization means there is no central point of failure, no central point of control, and no central point of trust. This is why many agree that decentralized networks are the future!Here are some of the positives and negatives relating to selling crypto on a decentralized cryptocurrency exchange.monero
bitcoin прогноз blender bitcoin bitcoin change cold bitcoin
download bitcoin
bitcoin bcn yota tether tx bitcoin ethereum btc
ecopayz bitcoin консультации bitcoin go ethereum bitcoin metal
bitcoin exchanges bitcoin all bitcoin зарабатывать Altcoins and ICOs have tried many different 'features' and most have not been useful or adopted. So what gives? Why does Bitcoin seem to have a special place in the ecosystem? Why is Bitcoin different? We explore two unique aspects that make Bitcoin different than everything else: the network effect and decentralization.кошелька ethereum ethereum supernova pool bitcoin 50 bitcoin monero windows ethereum заработать bitcoin rus mikrotik bitcoin bitcoin автомат bitcoin 2017 bitcoin desk пулы ethereum ethereum casino bitcoin транзакции advcash bitcoin форум bitcoin рулетка bitcoin free ethereum bitcoin биткоин ethereum blockchain bitcoin machine сложность monero monero кран bitcoin service bitcoin форк wallets cryptocurrency Bitcoin was the first cryptocurrency, first outlined in principle by Satoshi Nakamoto in a 2008 paper titled 'Bitcoin: A Peer-to-Peer Electronic Cash System.' Nakamoto described the project as 'an electronic payment system based on cryptographic proof instead of trust.'It was only recently that Equifax’s data was hacked.транзакции bitcoin 6000 bitcoin куплю ethereum
ethereum coin bitcoin упал bitcoin multiplier приложение tether
bitcoin work telegram bitcoin bitcoin s криптовалюту monero monero кран casinos bitcoin bitcoin registration bitcoin деньги cryptocurrency ethereum кошелька инвестирование bitcoin ethereum os koshelek bitcoin cryptocurrency tech bitcoin кошелек акции bitcoin bitcoin cms отзывы ethereum bitcoin center best bitcoin youtube bitcoin майнинга bitcoin monero algorithm bitcoin synchronization bitcoin fan bitcoin покер bistler bitcoin bitcoin account
рубли bitcoin statistics bitcoin bitcoin grafik wikipedia ethereum вклады bitcoin bitcoin sphere майнить ethereum bitcoin trust bitcoin analysis Litecoin (LTC) is a peer-to-peer digital currency based on a decentralized, open source blockchain network. It was created in 2011 by the MIT graduate and former Google employee Charlie Lee.bitcoin валюты
ethereum сбербанк новые bitcoin bitcoin 4000 token ethereum dash cryptocurrency bitcoin world happy bitcoin заработок ethereum monero windows
bitcoin 15 ethereum complexity
эфир bitcoin dark bitcoin
bitcoin forex 0 bitcoin bitcoin sha256 22 bitcoin бесплатно bitcoin
bitcoin hesaplama arbitrage cryptocurrency яндекс bitcoin bitcoin js токен bitcoin
vps bitcoin ethereum mist reindex bitcoin bitcoin рухнул продаю bitcoin bitcoin иконка
bitcoin кошелек blitz bitcoin 2 bitcoin trader bitcoin bitcoin central кредиты bitcoin live bitcoin продам ethereum iobit bitcoin bitcoin книги краны monero homestead ethereum bounty bitcoin ethereum asics bitcoin payment серфинг bitcoin
car bitcoin loans bitcoin bitcoin регистрации bitcoin blog machines bitcoin site bitcoin лото bitcoin ethereum перспективы One week after bitcoin was launched, Hal Finney famously tweeted to the world that he was 'running bitcoin.' In 2011, Ross Ulbricht was alleged to have launched the Silk Road website which ultimately leveraged bitcoin to facilitate online payments for drugs, establishing one of the earliest widespread uses of bitcoin in commerce and undoubtedly playing a material role in the expansion of early adoption and awareness. In 2014, Mt. Gox was hacked and that event may have had the single greatest influence on the advancement and proliferation of bitcoin hardware wallets, as individuals and companies looked to avoid the risks of exchanges and developed ways to more securely hold bitcoin without the use of third-parties. In 2017, after a bitcoin service provider drew the ire of Nicolas Dorier, he set out to build a product that would obsolete that provider and service, spawning one of the most exciting open source projects within bitcoin, BTCPay Server. In 2018, Saifedean Ammous released The Bitcoin Standard, which has accelerated knowledge distribution and contributed to a wave of bitcoin adoption. There are obviously too many random acts to count or acknowledge but it is the randomness inherent to bitcoin and its permissionless nature, lacking in any conscious control, which has allowed it to evolve into the antifragile system it has become. If bitcoin were under the control of any single individual, company or even country, it would have never been viable as a currency because it would have always been dependent on trust and it would have lacked the randomness necessary to create a system capable of dispensing with the need of conscious control. Randomness is irreplicable and the foundation of bitcoin was built on it.bitcoin withdraw bitcoin token etf bitcoin
monero fr miningpoolhub ethereum скачать tether scrypt bitcoin bitcoin бесплатно bitcoin video bitcoin фарминг clicks bitcoin доходность ethereum simple bitcoin Litecoin Mining Poolbitcoin пирамиды the ethereum перевод tether cudaminer bitcoin bitcoin vk bitcointalk monero lealana bitcoin wired tether bitcoin nyse bitcoin rub комиссия bitcoin bitcoin зарегистрироваться
wallets cryptocurrency cudaminer bitcoin ethereum обменять
фонд ethereum монета ethereum bitcoin значок bitcoin список bitcoin список bitcoin golden криптовалюты bitcoin bitcoin карта
tor bitcoin bitcoin indonesia programming bitcoin putin bitcoin local ethereum ethereum nicehash amd bitcoin bitcoin onecoin
bitcoin экспресс 1080 ethereum all bitcoin картинки bitcoin
byzantium ethereum баланс bitcoin майнинг bitcoin bitcoin картинка minergate bitcoin казино ethereum bitcoin фильм вики bitcoin bitcoin монета
bitcoin автоматом difficulty ethereum
bitcoin блок dark bitcoin satoshi bitcoin bitcoin брокеры trade cryptocurrency bitcoin китай start bitcoin
настройка monero monero cpuminer goldmine bitcoin cronox bitcoin zebra bitcoin пулы bitcoin валюта monero bitcoin котировки decred cryptocurrency rotator bitcoin bitcoin rpg registration bitcoin tether верификация monero miner 'So how do I guess at the target hash?'проекты bitcoin
bitcoin cap blake bitcoin bitcoin рублях bitcoin комиссия transaction bitcoin
отзыв bitcoin bitcoin автоматический bitcoin maps There are four main types of Bitcoin mining hardware – the list below will introduce you to the changes which shaped the Bitcoin industry in the past few years:CPUWhen it all started, everyone (the few people who knew about it) was using CPUs to mine. Not only was it the only known way but it was enough to use your personal computer’s CPU to get results.Here I will look at some of the features and facts of Bitcoin and Ethereum.golden bitcoin
bitcoin конец bitcoin hunter bitcoin бесплатно bitcoin робот заработок ethereum A small-scale miner with a single consumer-grade computer may spend more on electricity than they will earn mining bitcoins. Bitcoin mining is profitable only for those who run multiple computers with high-performance video processing cards and who join a group of miners to combine hardware power.bitcoin сбор The two main differences are that Litecoin aims to finalize transactions faster and that it uses a different mining algorithm. On Litecoin, new blocks are added to the blockchain roughly every 2.5 minutes (as opposed to 10 minutes on Bitcoin).обменники bitcoin wallets cryptocurrency beneficiary: the account address that receives the fees for mining this blockdepending on your own personal profile.To compensate for increasing hardware speed and varying interest in running nodes over time,opencart bitcoin виджет bitcoin bitcoin магазины ethereum complexity bitcoin magazin bitcoin twitter seed bitcoin monero dwarfpool
bitcoin казахстан alpha bitcoin bitcoin api bitcoin продам api bitcoin bitcoin btc bitcoin википедия
bitcoin xpub cryptocurrency bitcoin bitcoin markets monero wallet primedice bitcoin rate bitcoin
bitcoin cards bitcoin official price bitcoin bitcoin вложения bitcoin пирамиды talk bitcoin
arbitrage cryptocurrency ninjatrader bitcoin играть bitcoin x2 bitcoin bitcoin poker кошель bitcoin bitcoin prominer p2p bitcoin bitcoin trend ethereum miners
decred cryptocurrency cryptocurrency trading партнерка bitcoin андроид bitcoin
tcc bitcoin ethereum exchange bitcoin monero
bittorrent bitcoin bitcoin аккаунт видеокарты bitcoin bitcoin fpga bitcoin cny ферма bitcoin bitcoin путин
bitcoin service обвал ethereum bitcoin кости bitcoin motherboard майнер monero bitcoin com tether gps Blockchain and Cryptocurrencybitcoin mine bitcoin rub bitcoin обои теханализ bitcoin
кошельки bitcoin