Introduction to Ethereum (annotated version)
Editor's Note: This article comes fromEthereum enthusiastEditor's Note: This article comes frombitsonblocksEthereum enthusiast
(ID: ethfans), author: Bits on Blocks, source:
introduction
, translation: ViolaH & Elisa, published with permission.
Editor's Note: This article was originally written in 2016, and it is an introductory material for many people to understand Ethereum. We retranslated this article and added some annotations to keep the introductory material up-to-date. See "A Basic Introduction to Ethereum" for the old translation.
introduction
The concept of Ethereum is based on blockchain and cryptocurrency. Readers who are not familiar with blockchain and Bitcoin can read "Bitcoin Introduction" and "Blockchain Technology Introduction". This article assumes that the reader has some familiarity with how Bitcoin works.
What is Ethereum?
Ethereum is a software that runs on a computer network, enabling data and some programs called smart contracts to be copied and processed in the network without a central coordinator. Ethereum's vision is to create a non-downtime, censorship-resistant, self-sustaining decentralized world computer.
For related information, please see the public website established for Ethereum by the Ethereum Foundation: https://www.ethereum.org
Bitcoin realizes the verification, replication and storage of transaction data on countless computers around the world (hence the name "distributed ledger"). Ethereum, on the other hand, expands the concept of blockchain in Bitcoin and goes a step further, hoping to run computer code equally and unbiasedly on countless computers around the world.
Bitcoin implements distributed data storage, and Ethereum implements distributed data storage and computing in the same way. (On the whole), Ethereum is like a computer, and the computer program running on it is called a "smart contract". (Practically speaking), a network participant runs these programs ("smart contracts") on his computer using an operating system called the "Ethereum Virtual Machine".
Editor’s Note: It’s easier to put it this way: There are millions of people running Ethereum client software on their computers, and those computers communicate with each other and pass data. As long as the data conforms to certain rules ("Ethereum Consensus Rules"), the client software will use the data according to some rules, specifically, use these data in the EVM ("Ethereum Virtual Machine") (equivalent to Windows or Android) to run some program ("smart contract"), and then get the result. Interestingly, as long as everyone abides by the same rules and communicates with each other, countless nodes will get the same result (“consensus”) (but consensus generally takes time, not instantaneously).
You can refer to the following figure to understand:
(The bottom layer is to communicate with each other, the middle layer is to reach a consensus on these data, and the top layer is to use these data to drive the operation of the application)
In addition, this process is also related to a very interesting concept: "trusted computing", which refers to the trustworthiness of the computing process. Those who are interested can read "The Dawn of Trusted Computing".
How to "run" Ethereum?
You can download the Ethereum client software. Of course, if you have enough patience, you can also write one yourself. Similar to software like BitTorrent and Bitcoin, an Ethereum client connects you on the Internet to other people using the same client software so that you can download the Ethereum blockchain from them. The Ethereum client software will also independently verify that each block received complies with Ethereum's rules.
The Ethereum client software can be used to:
Connect to the Ethereum network
Explore Ethereum's Blockchain
Create new transactions and smart contracts
run smart contract
Mining new blocks
Editor's note: The so-called "blockchain" is a series of transaction data, which are confirmed by all computers in the network to comply with the (at that time) rules and executed ("transaction" mainly refers to the transfer of cryptocurrency ). And "mining a new block" means trying to spread some data for other computers to execute. The reason why it is called "block" is that these transactions are packaged into a data block at this time for transmission (other times, transactions Data can also propagate independently).
The "blockchain" we usually refer to refers to a set of technologies (computer interaction protocols) that enable the above-mentioned system (all computers save and execute the same transaction data).
In this way, your computer becomes a node in the network, running the "Ethereum Virtual Machine" and acting in unison with all other nodes. On a peer-to-peer network, there is no master server, and any computer has equal power and status.
Editor's Note: As of May 2019, there are approximately 6,000 nodes (also known as "full nodes") holding the entire Ethereum blockchain, the "numerous" above. Because the network is open, the number of nodes is constantly changing.
Similarities Between Ethereum and Bitcoin
I think the easiest way to understand Ethereum is to compare the similarities and differences between Ethereum and Bitcoin (a simpler system). Without further ado, let's talk about the same.
Ethereum will also form a blockchain
Like Bitcoin, Ethereum also forms a blockchain, which contains blocks of data (transaction data and smart contract code). After some participants create and mine blocks, they are distributed to other participants for verification (the legality of this block).
To understand what information is recorded on the Ethereum blockchain, please see this "block explorer": https://etherscan.io
Each block references the hash or "digital fingerprint" of the previous block, so that the blocks are linked together to form a chain. For a more detailed introduction to blockchain technology, please refer to: "Introduction to Blockchain Technology"
Editor's Note: As mentioned above, participants can organize some data into a "block" for dissemination. After receiving the block, other nodes will first verify that the block symbol does not conform to our predetermined rules, and execute the block if it meets If the transactions in the block do not match, the block will be rejected: the transactions in it will not be executed, and the block will no longer be propagated.
Regarding the "hash value", the simple understanding is the result of a function. The same data input function must get the same result, and the results of different data input functions can almost be said to be different (the probability of the same is extremely low), so Can be marked with a hash value. Please see "Emoji expression takes you to understand the hash function in seconds"
Ethereum is a permissionless open network
Like Bitcoin, the Ethereum mainnet is open and permissionless. Anyone can connect to the network by downloading or writing their own software. They can start creating transactions and smart contracts, verifying transactions, and even mining (mining blocks) without logging in to a website or reporting to anyone.
Generally speaking, when people talk about Ethereum, they refer to this open version without permission. However, like Bitcoin, with the Ethereum client software, you only need to add a few settings to create a private network that is independent of the public network. However, tokens and smart contracts in private networks are not yet compatible with public tokens.
To learn more about the difference between a permissionless open network and a private permissioned network, read: "The Different Types of "Blockchains""
Ethereum Mining with Proof of Work (PoW)
Like Bitcoin, Ethereum miners need to find a solution to a mathematical problem when creating a valid block. The solution process is haphazard, so it must invest a lot of electricity and use computers to continuously calculate.
Ethereum's proof-of-work mathematical puzzle is called "Ethash", which is slightly different from Bitcoin's PoW algorithm. People can also participate in Ethash mining with common hardware. In Bitcoin mining activities, special-purpose hardware (ASIC) is very common, and Ethereum's Ethash is designed to reduce the efficiency advantage of special-purpose hardware.
For more information on mining, see: "Introduction to Bitcoin Mining"
Editor's Note: Specifically, in the PoW system, when the miner packs the transaction, a structured data ("block header") will be formed (this part of the structured data is naturally different for different transactions), and the block header also contains Some other data, such as the timestamp when the block was created, the hash value of the parent block, and so on. The regularity requirement of the block is that the hash value of the block header (as a value) meets certain requirements ("difficulty requirements") (for example, the difficulty requirement of the Bitcoin protocol is that the "0" at the beginning of the hash value reaches a certain number ). However, as mentioned above, the hash value of certain data is deterministic, and there is no guarantee that a hash value that meets the requirements can be generated based on the above data alone, so the block producer must constantly change one of the data that has no special meaning (“ Block nonce") until the hash value of the block header meets the difficulty requirement (otherwise, even if it is propagated, other nodes will not accept the block).
On the Ethereum roadmap, there is a protocol plan called Casper, which changes the power-consuming proof-of-work into a more energy-efficient proof-of-stake, and will be included in the future "Serenity" version of Ethereum. release.
Editor’s Note: The so-called Proof of Stake (PoS) is to use the proportion of participants’ funds in a fund pool to determine the probability of TA’s block production. Participants no longer compete with each other to calculate the hash value that meets the difficulty. There is no need to invest a lot of electricity to calculate.
Since 2014, the Ethereum core development team has been working on a proof-of-stake consensus mechanism. As of this time (May 2019), the proof-of-stake scheme Casper implemented on the Ethereum mainnet has been basically finalized and is expected to be deployed by the end of 2019, opening a new chapter for Ethereum.
Ethereum has a built-in cryptocurrency
The token of Ethereum is called Ether, and the English abbreviation is ETH. The current market has accepted the exchange of ETH with other cryptocurrencies and sovereign currencies, just like accepting BTC. The current value of ETH is around $13/ETH (October 2016). Similar to Bitcoin, the ownership of Ethereum tokens is also recorded on the Ethereum blockchain, although technically speaking, it is recorded in a slightly different way.
Editor’s Note: The point here is that the built-in cryptocurrency is issued as blocks are mined: every time a block is produced, a (predetermined) amount of cryptocurrency is issued to the miner who mined the block. people ("miners").
The "transactions" mentioned many times above mainly refer to the transfer transactions of Bitcoin on the Bitcoin blockchain, while they are more diverse on the Ethereum, mainly including the transfer of ETH, the interaction between users and smart contracts, And the transfer of tokens issued by smart contracts.
Since the original article was written, the price of ETH has been rising from $13 (about 87 yuan), reaching a high of $1347 (about 9000 yuan) (January 2018) and then gradually falling to around $100 (January 2018 2019), and is now starting to gradually recover to $250 (May 2019). Additionally, the prices of cryptocurrencies against fiat currencies fluctuate wildly on an almost daily basis.
Differences between Ethereum and Bitcoin
Get your stools ready, we're going to start a more technical and complex topic.
Ethereum’s block times are shorter
In the Ethereum network, the time interval between each block is about 14 seconds, while the block interval of Bitcoin is about 10 minutes. This time difference means that if you send a Bitcoin transaction and an Ethereum transaction at the same time, generally speaking, the speed of recording the Ethereum transaction to the Ethereum blockchain is faster than the speed of recording the Bitcoin transaction to the Bitcoin blockchain. quick. We can also understand this as the Bitcoin network writes to the database every 10 minutes, while the Ethereum network writes to the database every 14 seconds.
Editor's Note: While Bitcoin and Ethereum differ on this point, the principle behind this property is the same: they are PoW systems. As mentioned above, countless computers are in an open network, and all computers can exit or join at any time, so this brings about a serious problem: If all computers operate independently and process the data they receive, then These computers cannot form a "consensus", and the entire system cannot realize basic functions (such as currency transfer, because each has its own transaction history, and no one can determine how much money is in an account). Therefore, the meaning of PoW is tantamount to saying: If you want to record a sum on this ledger, please first prove that you have spent a lot of computing resources. Supplemented by the change of "difficulty requirements", we can adjust the workload required for block generation, and then adjust the block generation interval of the entire network. There may be many reasons why such a stable block interval should be achieved (such as the expected number of additional issuances, such as the security of the network), which will not be elaborated here.
Ethereum blocks are smaller
In Bitcoin, the upper limit of block size is measured in bytes, which is currently 1MB, while Ethereum uses a unit to measure the computational complexity of smart contracts to mark the size of the block. This size is called "Block Gas Upper Limit". ", and the block Gas upper limit can be changed block by block (Bitcoin's block size upper limit is certain).
Currently, Ethereum’s block size cap is around 1,500,000 Gas. Between users (that is, not interacting with smart contracts), the basic transaction or payment via ETH has a complexity of 21,000 Gas, so you can put 70 transactions into a block (1,500,000 divided by 21,000). In today's Bitcoin network, a block can contain 1500-2000 single transactions.
In terms of numbers, most Ethereum blocks are currently under 2KB.
Editor's Note: As of May 17, 2019, the gas limit for Ethereum blocks has reached 8 million Gas. The size of a single block of data is several hundred KB.
Ethereum uses EVM to run smart contracts
Compared to Bitcoin's original scripting language, the code ("smart contracts") that can be deployed on Ethereum is more advanced and friendly to developers. The smart contract code runs in the Ethereum virtual machine environment, and all computers in the network run EVM. If you are familiar with Microsoft Excel macros (code snippets run by Excel), it should be easy to understand that smart contracts are code snippets run by the Ethereum Virtual Machine.
In many materials, people usually refer to the Ethereum smart contract as "Turing complete". This means that smart contracts are fully functional and can perform all calculations that can be performed in other programming languages.
Issuance of Ethereum
How is ETH generated? The biggest difference between the issuance of ETH and BTC is that the issuance of BTC is halved about every 4 years, while the issuance of ETH remains unchanged (maybe only before the Serenity version).
How is ETH generated? The biggest difference between the issuance of ETH and BTC is that the issuance of BTC is halved about every 4 years, while the issuance of ETH remains unchanged (maybe only before the Serenity version).
Editor's Note: It's not staying the same. As mentioned above, on the blockchain, the native cryptocurrency is issued every time a block is produced. We call this amount of additional issuance "block rewards". The block reward of Ethereum has also been cut several times. In October 2017, the block reward was reduced from 5 to 3 ETH. In February 2019, the block reward of Ethereum was reduced to 2. Therefore, I am replacing the author's original graph here with the actual change graph of ETH supply.
Pre-mine + Block rewards + Uncle rewards + Uncle referencing rewards
block reward
pre-mining
During the crowdsale in July and August 2014, the amount of ETH issued was about 72 million. The ETH generated in the crowdsale is called "pre-mining". It was decided that the issuance of ETH after the crowdsale would be limited to no more than 25% of the total crowdsale per year (that is, no more than 1,800 Ten thousand).
block reward
Currently, mining a block earns 5 new ETH. If a block is mined every 14 seconds, there are 31.5 million seconds in a year (365x24x60x60), which means 2.25 million blocks can be mined per year. 2.25 million blocks, 5 ETH per block = 11.3 million ETH/year. This is in line with the promise of generating less than 18 million ETH per year.
Uncle block reward
In fact, the circulation of ETH will be slightly greater than 18 million. Because some blocks were mined later, they did not become part of the main chain. In the Bitcoin network, we call these late-mined blocks "orphan blocks", which are completely discarded, but in Ethereum, these blocks are called "uncle blocks", and subsequent blocks can be These "uncle blocks" are referenced. If someone references an "uncle block", the miner who dug out the "uncle block" will be given an "uncle block reward" of 4.375 ETH (equivalent to seven-eighths of the normal block reward). At present, Ethereum generates about 500 uncle blocks every day, that is, an additional 2,000 ETH enters circulation every day (at this rate, an additional 7 million ETH will be issued every year).
Rewards for referencing uncle blocks
Miners who produce blocks after an uncle block can also get 0.15ETH (up to 2 uncle blocks).
Editor's note: Uncle block rewards are a difficult point for many friends to understand, and it does require a lot of background knowledge. To put it simply: in the network, it takes time to propagate blocks, so after a certain block is dug out, only some nodes may receive this block within a certain period of time, while other nodes receive another block during this period. block and treat it as the latest block, the consensus algorithm used by the PoW system cannot immediately determine which is the main chain. The block generation speed of Ethereum is relatively fast, and this situation may happen frequently, so this kind of economic incentive is arranged on the consensus algorithm to alleviate this situation - even if there are uncle blocks, the main chain is still basically determined. For details, please see "Ethereum Design Principles"
mining rewards
Changes in the output of Ethereum in the future
When Ethereum changed from proof-of-work (including uncle block reward rules) to proof-of-stake mechanism, the impact of the mechanism change on issuance is still uncertain. The proof-of-stake mechanism will use a protocol called Casper (yes, that pixie, who dared to say that cryptonerds have no sense of humor?). The ETH issuance rate under the Casper protocol is likely to be much lower than the issuance rate under the Ghost protocol.
mining rewards
So, what can miners get in mining?
In Bitcoin, every time a new block is dug, the miner will get 12.5 bitcoins (this is the current situation); in addition, there is a transaction fee attached to the miner by the initiator of the transaction packaged in the block.
In Ethereum, miners can get:
Mining a new block will reward 5 ETH (or an uncle block will reward 4.375 ETH);
In addition, another small reward for referencing up to two uncle blocks, (1/32 block reward, ie: each uncle block reward 1/32×5 ETH = 0.15625 ETH);
The gas fee paid by the transaction initiator for contract operation and transfer
Currently, the average upper limit of Gas per block is 1,500,000, and the average price of each Gas in the block network is 0.000000022 ETH, that is to say, the Gas reward that a miner may get from an entire block is 0.033 ETH currency. It should be noted that the gas in the contract is paid with the ether currency in circulation, not with the newly created ether currency.
Editor's note: The person who initiates the transaction needs to set the Gas price for the transaction (that is, how much he is willing to pay per unit of Gas), and this Gas Price will become one of the basis for miners to choose whether to package the transaction. Because people's demand for transactions is not always the same, Gas Price will also fluctuate with the current changes in people's demand for transactions on the blockchain.
Other parts of Ethereum: Swarm and Whisper
Computers need to compute, store data and interact. Ethereum needs efficient and robust ways to realize its vision of a non-downtime, censorship-resistant, and self-sustaining decentralized world computer. The Ethereum Virtual Machine is only one element of the whole.
The Ethereum Virtual Machine is a computing primitive that can run contract logic.
This computing does not depend on a central server
Like BitTorrent, the Swarm protocol is a peer-to-peer file sharing protocol, except that it incentivizes file storage and sharing with small ether payments. Files are divided into blocks, distributed and stored among network participants. Nodes that store and disseminate data blocks can get ETH as a reward from requesting storage and retrieval services.
Whisper is an encrypted communication protocol that allows nodes to send information directly and securely, and also helps information senders and information receivers to block redundant third parties
smart contract
Whisper protocol communication does not need to rely on a central server
Concepts of Ethereum
smart contract
Smart contracts are small programs stored on the Ethereum blockchain. These programs can be activated and run with an appropriate amount of Ethereum (editor's note: other special Tokens may also be required for activation). For more information about smart contracts, please see: "Introduction to Smart Contracts"
Here's an example from Wikipedia about smart contracts:
- Image source: https://en.wikipedia.org/wiki/Solidity -
Once the contract is uploaded successfully, it works like a jukebox: to run the contract, you just send it a transaction containing the payment in ether, possibly with some additional information.
account
Each mining computer will use the Ethereum Virtual Machine to run the smart contract (as part of their mining process) and come up with the final output value. In theory, if no one messes it up, every computer on the Ethereum network will output the same result because the users are all running smart contract code that contains the same information.
After mining a block, the winning miner publishes the block to other users of the network, and other miners verify and put the block into their blockchain after they get the same result. This is how Ethereum's blockchain state is updated.
account
In Bitcoin, people call the place where Bitcoin is stored an "address", which is like a bank account, except that it is stored in Bitcoin. In Ethereum, "accounts" are used to store Ethereum. There are two types of accounts:
An account that only stores ether, which is similar to a bitcoin address. It is also sometimes referred to as an "external account" (EOA). This kind of account will have a corresponding private key, and the private key holder can use the private key to sign the transaction of the account.
Here is an example of an account storing ether: https://etherscan.io/address/0x2d7c76202834a11a99576acf2ca95a7e66928ba0
An account that holds code (and possibly ETH or other tokens). As long as the appropriate amount of ether is deposited in, these smart contracts will take effect. After the smart contract is uploaded, its code has been stored on the Ethereum blockchain, waiting to be activated and used.
An example of a contract account is as follows: https://etherscan.io/address/0xcbe1060ee68bc0fed3c00f13d6f110b7eb6434f6#code
Uncle blocks and orphan blocks: blocks that are almost on the main chain
The block generation rate of Ethereum is much higher than that of Bitcoin (250 blocks per hour in Ethereum vs 6 blocks per hour in Bitcoin). The faster blocks are generated, the probability of "block collisions" increases, that is, many valid blocks are generated almost at the same time, but only one of them can be placed in the main chain. Technically, although the transactions contained in these blocks that are not on the main chain are real, these data cannot be considered part of the main chain.
In the Bitcoin protocol, such blocks that are not on the main chain are called "orphan blocks". Orphan blocks are not part of the main chain and will not be referenced by blocks on the main chain.
In Ethereum, these blocks are called "uncle blocks", and subsequent blocks within a certain distance can refer to uncle blocks (see the "Issuance of Ethereum" section above for details). Although the data in the uncle block will not come in handy in the end (that is, the transactions on the uncle block will not be executed), the miners who dig out the uncle block can still get a slightly smaller block reward.
This led to two important results:
This will incentivize miners to maintain mining motivation, even if the mined blocks cannot be uploaded to the main chain (because the high block generation rate generates more orphan blocks and uncle blocks)
Acknowledging the energy expended in creating uncle blocks also improves blockchain security
Editor’s note: All in all, Ghost is a protective measure in the process of rapid block generation, so that miners who have not dug up the main chain block will not suffer a lot of losses, and have the motivation to maintain the main chain.
Gas and Gas Price
When activating a smart contract, you are tantamount to requesting all miners in the entire network to perform the calculation work in the contract. This costs the miners time and energy, for which users should of course pay them. Gas is the mechanism for paying service fees.
Payment item (unit: Ether) = actual amount of Gas used (unit: Gas) * gas price (unit: Ether/Gas)
gas price
Gas quantity
The more complex the smart contract (the number and type of calculation steps, the size of storage, etc.), the more Gas is required to complete the contract operation. If you use the analogy of a coin-operated jukebox, it is like that the longer you order a song, the louder you sing, and the more you need to pay.
gas price
Although the complexity of contracts varies, the amount of Gas required to run a specific contract is fixed (the difference in handling fees is mainly due to the Gas price), and the Gas price is determined by the person who wants to run the contract when requesting to run the contract. specified (sort of like Bitcoin's transaction fees). Miners will look at the price of Gas to decide whether they are willing to run the contract. If you want miners to run the contract, just charge a high price. It can be said that the Gas market is a highly competitive auction field, and it depends on how much users are willing to pay for running smart contracts.
Why is the Gas mechanism needed?
Running a smart contract costs Gas/Ether currency/money, which effectively prevents people from activating the contract at will, thus avoiding problems like spam transactions that may congest the network when it runs for free.
Editor's Note: What is not stated here is that the amount of Gas traded and the Gas price can be freely adjusted by users. If the amount of Gas is not given enough to complete the calculation in the contract, then the system will completely roll back, as if the transaction has never happened, although the Gas fee will still be fully handed over to the miners; if the amount of Gas given is too much, then the completion After the relevant calculation, the remaining Gas fee will be automatically refunded to the account that initiated the transaction.
unit of ether
For example, one dollar can be divided into 100 cents, and one bitcoin can be divided into 100,000,000 sataoshi. Ethereum also has a proprietary unit naming rule.
The smallest unit of ether is wei, each ether is equal to 1000,000,000,000,000,000 wei, and there are other units, such as: Finney, Szabo, Shannon, Babbage and Ada. These names are derived from scientists who have made outstanding contributions to cryptocurrency and the Internet.
Wei and Ether are the two most common currency denominations.
Smart contract languages: Solidity / Serpent, LLL
There are three common languages for smart contracts, all of which can be compiled into smart contracts and run on the Ethereum Virtual Machine. The three languages are:
Solidity - Javascript-like language, is currently the most popular scripting language for powerful smart contracts.
Serpent — A Python-like language that was commonly used in the early days of Ethereum.
LLL - Similar to Lisp, only used in earlier languages. LLL is perhaps the most difficult language to write.
Editor's Note: As of today (May 17, 2019), Solidity has become the most commonly used contract programming language in the Ethereum ecosystem. The remaining two languages are rarely used or even deprecated. In addition, Ethereum is researching to upgrade the Ethereum virtual machine EVM to eWASM, and WebAssembly supports the development of many advanced computer languages, which is expected to further enhance the friendliness and security of Ethereum contract writing.
In addition, some people pointed out that we should not preconceived that Solidity and Javascript are very similar, so that we will fall into many misunderstandings during the learning process.
Ethereum software: geth, eth, pyethapp
The official Ethereum clients are all open source, so you can see the code behind it, and tweak it to create your own. The most popular clients are as follows:
geth (written in Go) https://github.com/ethereum/go-ethereum
eth (written in C++) https://github.com/ethereum/cpp-ethereum
pyethapp (written in Python) https://github.com/ethereum/pyethapp
All of the above are command-line based programs (the ones with green text on a black background), so to use a graphical interface you need to use other software. Currently the most popular official GUI software is Mist (https://github.com/ethereum/mist). Mist uses geth and eth as its core.
In other words, geth and eth are ugly code under the hood, and Mist is the beautiful interface running on top of it.
Editor's Note: In March 2019, the Mist project ceased operations and the team split and moved to different areas. The two most common clients in the Ethereum ecosystem, Geth and Parity·Ethereum, have also developed quite well, and both have complete graphical interfaces.
Footsteps: A Chronology of Events in Ethereum
At the end of 2013, Vitalik Buterin discussed the concept of "Ethereum" in a white paper. In April 2014, Dr. Gavin Wood developed this concept further in the Yellow Paper. Since then, Ethereum development has been managed by a community of developers.
In July and August of the same year, Ethereum crowdfunded for development, and its open mainnet went live on July 30, 2015.
Crowdfunding on Ethereum
During July-August 2014, the development team was funded through an online sale of ETH tokens - people could buy ETH with Bitcoin at a rate of 2000 ETH : 1 BTC at the time (as of January 2016, on the open market 1 BTC can be exchanged for 50 ETH).
Those who participate in the crowdfunding can pay with a bitcoin account and then receive a wallet containing the corresponding amount of ether. For more technical information, please refer to the Ethereum blog: https://blog.ethereum.org/2014/07/22/launching-the-ether-sale/
During this period, the Ethereum team sold more than 60 million ether and received more than 31,500 bitcoin, worth about $18 million at the time. The team mined another 20% (12 million ETH) to support development and the Ethereum Foundation.
Software Release Codenames: Frontier / Homestead / Metropolis / Serenity
The naming of the Ethereum software is very interesting.
Olympic (Test Network): Launched in February 2015, the token was not really ether when the test was released. Today, the testnet remains parallel to the main live network for developers to test code.
Frontier: Released on July 30, 2015, Frontier is the first online version that can mine, develop, and run contracts.
Serenity: Unreleased - Upgrade from Proof of Work to Proof of Stake (Casper).
Summarize
Editor's Note: The above codenames are also considered to be different stages of Ethereum's roadmap and development. At the time of writing (October 2016), the Metropolis ("Metropolis") stage had not yet been released. In October 2017, the first phase of Metropolis, Byzantine ("Byzantium") was released; in February 2019, the second phase of Metropolis, Constantinople ("Constantinople") was released, and it is expected to enter the first phase of Serenity in late 2019. stage.
secondary title
Summarize
The Ethereum development team is committed to building a non-downtime, censorship-resistant, and decentralized world computer that can run computations, store data, and allow interactions.
Ethereum has a public, permissionless, open-source version whose code copies have been adopted and adapted for private networks. Public versions and private networks solve different problems.
Although the current technology is not yet mature, we believe that after more and more people use, test, develop and develop software on Ethereum, it will develop more and more steadily.
In the blockchain world, Ethereum is one of the most exciting technologies, and the future development is worth looking forward to.
