Nonce Ethereum
mainstream digital currencies such as bitcoin, Puyin, Laite, Ethereum and dogcoin all exist in wallets, and wallets existed before the release of such currencies.
Blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it is characterized by "unforgeability", "trace in the whole process", "traceability", "openness and transparency" and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects
on January 10, 2019, the state Internet Information Office issued the regulations on the management of blockchain information services. In October 24, 2019, ring the eighteenth collective learning of the Central Political Bureau, general secretary Xi Jinping stressed that "block chain as an important breakthrough in core technology and independent innovation", "accelerating the development of block chain technology and instrial innovation". "Blockchain" has entered the public field of vision and become the focus of social attention
on December 2, 2019, the word was selected into the top ten catchwords of "biting words" in 2019
extended data:
Application of blockchain Finance:
since 2016, the major financial giants have also carried out blockchain innovation projects to explore the possibility of applying blockchain Technology in various financial scenarios. In particular, Puyin group took the lead in creating a "blockchain +" standard digital currency
standard digital currency refers to the process of assets identification, evaluation, right confirmation and insurance completed by a third party organization, which is written into the blockchain through careful digital algorithm to form the standard corresponding relationship between assets and digital currency, which is called standard digital currency
in order to realize the great leap forward development of blockchain finance, promote the new development of China's economy, accelerate the circulation of global assets, and realize the dream of rejuvenation that has been struggling for generations, Puyin group will hold the Guiyang strategic development ceremony of Puyin blockchain finance in Guizhou on December 9, 2016
the meeting will discuss the realization of digital circulation of assets by blockchain, the financial transaction mode of blockchain, and the application of blockchain services and social public instry. This conference will mark the beginning of the application of blockchain finance and the change and development of the new financial ecology
1. Blockchain links
as the name suggests, blockchain is a chain composed of blocks. Each block is divided into block head and block body (including transaction data). The block head includes the prevhash value (also known as hash value) of the previous block used to realize the block link and the random number (nonce) used to calculate the mining difficulty. The hash value of the previous block is actually the hash value of the head of the previous block, and the random number calculation rule determines which miner can obtain the right to record the block
2. Consensus mechanism
blockchain is accompanied by the birth of bitcoin, which is the basic technology architecture of bitcoin. Blockchain can be understood as an Internet-based decentralized accounting system. A decentralized digital currency system like bitcoin requires the consistency of accounting of honest nodes without a central node, which needs blockchain to complete. Therefore, the core of blockchain technology is a consensus mechanism to reach a consensus on the legitimacy of transactions between indivials without mutual trust without central control
there are four main types of consensus mechanisms in blockchain: pow, POS, dpos and distributed consistency algorithm
3. Unlocking script
script is an important technology to realize automatic verification and contract execution on blockchain. Every output of every transaction does not point to an address in the strict sense, but to a script. A script is like a set of rules that constrain how the receiver can spend the asset locked on the output
the validation of transactions also depends on scripts. At present, it depends on two kinds of scripts: Lock script and unlock script. Locking script is a condition added to the output transaction, which is realized by a script language and located in the output of the transaction. The unlocking script corresponds to the locking script. Only when the conditions required by the locking script are met can the assets corresponding to the script be spent, which is located in the input of the transaction. Many flexible conditions can be expressed by script language. Interpretation script is similar to the "virtual machine" in our programming field, which runs in every node of the blockchain network in a distributed way
4. Transaction rules
blockchain transaction is not only the basic unit of a block, but also the actual effective content recorded by the blockchain. A blockchain transaction can be a transfer, or the deployment of smart contracts and other transactions
as far as bitcoin is concerned, a transaction refers to a single payment transfer. The transaction rules are as follows:
1) the input and output of the transaction cannot be empty
2) for each input of a transaction, if its corresponding utxo output can be found in the current transaction pool, the transaction will be rejected. Because the current transaction pool is the transaction not recorded in the blockchain, and each input of the transaction should come from the confirmed utxo. If it is found in the current trading pool, it is Shuanghua trading
3) for each input in a transaction, the corresponding output must be utxo
4) each input unlocking script must verify the compliance of the transaction together with the corresponding output locking script
5. Transaction priority
the priority of blockchain transaction is determined by the blockchain protocol rules. For bitcoin, the priority of a transaction to be included in a block is determined by the time when the transaction is broadcast to the network and the amount of the transaction. With the increase of transaction broadcast time on the network and the increase of transaction chain age, the priority of transaction will be improved and eventually be included by the block. For Ethereum, the priority of the transaction is also related to the transaction fee that the publisher is willing to pay. The higher the transaction fee that the publisher is willing to pay, the higher the priority that the transaction is included in the block
6. Merkle proof
the original application of Merkle proof is bitcoin, which was described and created by Satoshi Nakamoto in 2009. Bitcoin blockchain uses Merkle proof to store transactions in each block. So that the transaction can not be tampered with, but also easy to verify whether the transaction is included in a specific block
7. RLP
RLP (recursive length prefix) is one of the main encoding methods of object serialization in Ethereum. Its purpose is to encode the sequence of arbitrary nested binary data.
At the end of March this year, bitmainland launched an ant miner X3 based on ASIC, which is mainly aimed at Monroe coin (XmR) and cryptonight algorithm dependent cryptocurrency. Monroe coin immediately issued a counter statement that it will change the core algorithm to fight against the invasion of ASIC computing power
what would be the result if it appeared in the world of digital cryptocurrency? That is, the wrong calculation results may be brought into the whole network without being discovered
More importantly, if a "calculator manufacturer" monopolizes the calculator market, it can also deliberately proce this kind of calculator with errors to change the mathematical rulesafter all, the "calculation" in the field of crypto digital currency is not as simple as 1 + 2 + 3. You can't compare paper currency with special currency by hand
the practical significance of computing power monopoly in mainland China
we have learned about attacks based on 51% computing power in various articles
but the reality is that although the global power of 78% was in Chinese mainland, fortunately, they were scattered in different pools and controlled by different people. p>
although all POW based cryptocurrencies have the risk of being attacked by 51%, few people can really launch attacks e to the dispersion of computing power
but what if the miners themselves don't want to attack, but the mining machinery manufacturers attack
still using the analogy just now, although each miner subjectively wants to do the problem checking independently, their calculator is manipulated remotely and gives consistent wrong answers. This may pose a great threat to digital cryptocurrency
however, the manufacturer with the absolute voice of mining machinery had such a problem in mainland China
in April 2017, the back door of antbled came out. Although this is described as a "vulnerability" in Chinese, antbled is more like a function that has been implemented and designed
anonymous people found that after an ant miner made by bitmainland was connected to the network, it would communicate with a domain name held by bitmainland on a regular basis and return the miner's serial number, MAC address and IP address to bitmainland's server. If the server of bitcontinent gives a negative signal, the miner will stop running
although bitcontinental responded that they could not shut down any mining machines that did not belong to them. However, the bitcoin core team has proved in experiments that this function has no verification. Anyone can shut down mining machines by forging DNS - but it also means that bitcoin mainland has the ability to shut down any sold mining machines
After, bitcontinent fixed this "loophole", but it caused heated discussion in the community. This has also set the tone that almost all pow blockchain communities are biased against mainland China
a few months later, under the leadership of bitcontinent, viabtc g out the first block and made a hard bifurcation with the blockchain of bitcoin. From then on, bitcoin BCH (bitcoin cash) appeared in the world
will the monopoly of mining machinery destroy the distributed system
facing this problem, we should have a clear answer now. That is, the monopoly of mining machinery will certainly affect the safe operation of pow digital cryptocurrency
the problem is not whether bitcontinental and its founder Wu Jihan are trustworthy, but that one of the values of any blockchain system is to operate safely without trust in any single company or indivial
even if the ASIC miner is not monopolized by bitmainland, the ASIC miner itself will increase the concentration of computing power
the ASIC used for mining has great requirements for ventilation, power and site, and has no use except for mining. At the same time, the calculation difficulty of the whole network is increased e to the powerful computing power
as a result, it is very difficult for external players to start mining in the next software on the computer as they did five years ago. And the recent centralized exchange is caused by frequent black incidents, which also proves that concentration in this unregulated market will definitely lead to insecurity
assuming that the bitcoin network runs on top of one million miners, no one can shut it down. And if the bitcoin network runs on 20 large mines, it's much easier to shut it down
and by the end of 2017, 78% of the effort was concentrated in mainland China, which led to a real possibility of Chinese mainland regulators' launching a deadly attack against the special currency. p>
moreover, most of the scenarios of using digital cryptocurrency are related to "decentralization". Once centralized, it means that these scenarios no longer exist. It turns a project that might have value into a pure waste of computing power
Then, what measures should we take in the face of this situationfirst of all, as the project side, it may be time to give up the pure POW mechanism. In fact, in many projects of issuing cryptocurrency, especially in asset securitization projects. Similar to the concept of stock in the real world, POS itself is more reasonable than pow
in the media that don't know about blockchain, we often hear such words as "bitcoin wastes a lot of computing power and has no value", which is reasonable to some extent. It is difficult for a POW based blockchain to bind the value of the project itself to the issued digital cryptocurrency - because the real value behind the price of the currency does not come from the project, but from the cost of maintaining computing power
and the hybrid mode of pow + POS is more like the future. In the hybrid mode, both coin holders and miners can participate in the major decisions of this community. If a decision is widely accepted, the blockchain will be soft forked to the latest state without excessive intervention of developers, and there will be almost no private resistance of miners or mining machines
secondly, as a retail miner, if you are still digging a pure POW mechanism currency, you should unconditionally support the bifurcation activities initiated by the community to resist the ASIC mining machine, even if it will lead to the failure of your mining machine
this may sound contradictory, but in the long run, it is better to promote the reform of the community and get more benefits in a currency controlled by the monopoly of computing power. Because in many conflicts between computing power and community in the past, the ultimate result is that the computing power owner will forcibly keep the old algorithm to hard fork the blockchain
just like Eth and etc, the classic Ethereum (etc), which belongs to the computing power master, has lost the support of developers and become an air coin with no vitality and impossible to develop applications
as a retail leek, you should be careful to trade the non mainstream digital currencies (except bitcoin) supported by bitmainland mining machinery, so as to avoid falling into a blockchain in which bitmainland controls the computing power completely
finally, if you are bitcontinent, what should you do
bitcontinent's goal is to become Intel, AMD and NVIDIA, make greater contributions to the whole computer instry, and become a great company, not just entangled in the immediate interests of mining
Wall Street financiers have long seen through the violence brought about by NVIDIA's video card mining. The rise and fall of the company's stock price has been consistent with the price of bitcoin, and even affected by the digital currency market. Citron, a well-known short seller, has recently been bearish on NVIDIA, arguing that the company has focused too much on providing services for digital currency miners rather than on serious businesses such as artificial intelligence, games and driverless driving
the mission of chip manufacturers is to provide more powerful chips to drive more intelligent services, and finally contribute to the real world, rather than become monopoly tycoons in the virtual world. When we no longer enter the gate of the virtual world, the only thing left is a deserted land
in an interview with US media last year, Wu Jihan disclosed that he would make an IPO with a market value of billions of dollars. As a company about to go public, bitmainland should not only be responsible to investors, but also accept investors' questions about the sustainability of its business. "If your mining machinery goes public, it will encounter a fork, what should you do?"
and this question, which needs to be asked after the listing, has already appeared: the current price of the split coin xmo after the Monroe team split is $7.50, while the current price of the real Monroe coin XmR is $194, and the split coin is completely abandoned by the Monroe community
before bitcontinent becomes the name of all blockchain communities, we can rely on the huge amount of capital accumulated in recent years to transform into an artificial intelligence chip company along the previous plan, rather than continue to develop a variety of digital currency mining machines to extract the last drop of oil before the ecological collapse
content source: phoenix.com
many new users believe that the sole purpose of mining is to generate ether in a way that does not require a central issuer (see our guide "what is ether?"). It's true. The token of Ethereum is proced in the process of mining, with a mining rate of 5 Ethereum coins per piece. But mining is at least as important. Usually, banks are responsible for keeping accurate records of transactions. They make sure that money is not created out of thin air and that users don't cheat and spend money many times. However, blockchain introces a new way to keep records, the whole network instead of intermediary, to verify transactions and add them to the public ledger
Ethereum mining
although "no trust" or "trust minimization" monetary system is the goal, there are still people who need to ensure the security of financial records and ensure that no one cheats. Mining is one of the innovations that makes decentralized records possible. Miners have reached a consensus on the history of transactions in terms of preventing fraud (especially double spending on ether) - an interesting issue that hasn't been addressed before the decentralized currency works on the blockchain. While Ethereum is looking at other ways to reach a consensus on the effectiveness of the deal, mining currently keeps the platform together
how mining works
today, the mining process of Ethereum is almost the same as that of bitcoin. For each transaction, the miner can use the computer to guess the answer repeatedly and quickly until one of them wins. More specifically, the miner will run the unique header metadata (including time stamp and software version) of the block through the hash function (which will return a fixed length, unordered string of numbers and letters, which appears to be random), changing only the 'nonce value', which will affect the hash value of the result
if the miner finds a hash that matches the current target, the miner will be granted ether and broadcast the block across the network for each node to verify and add to their own ledger . If miner B finds the hash, miner a stops working on the current block and repeats the process for the next block. It's hard for miners to cheat in this game. There is no way to fake the work and come up with the right answer to the puzzle. That's why solving puzzles is called "proof of work."
on the other hand, others have little time to verify whether the hash value is correct, which is exactly what each node does. About every 12-15 seconds, a miner finds a stone. If the miner starts to solve the puzzle faster or slower than this, the algorithm will automatically re adjust the difficulty of the problem so that the miner can rebound to about 12 seconds of solution time
miners earn these ethers randomly, and their profitability depends on their luck and the computing power they put in. The specific workload verification algorithm used by Ethereum is called "ethash", which aims to require more memory, making it difficult to mine with expensive ASIC. Special mining chips are now the only profitable way to mine bitcoin
in a sense, ethash may have achieved this goal successfully, because dedicated ASIC is not available for Ethereum (at least not yet). In addition, as Ethereum aims to shift from proof of work mining to "proof of equity" (which we will discuss below), buying ASIC may not be a wise choice because it may not prove useful for a long time< However, Ethereum may never need miners. Developers plan to abandon proof of work, the algorithm currently used by the network to determine which transactions are valid and protect them from tampering to support proof of equity, which is guaranteed by token owners. If and when the algorithm is launched, proof of equity can become a means to achieve distributed consensus, and the consensus uses less resources.
first, you need to create a "Genesis" JSON configuration file, which describes some parameters of the genesis block. The following is the content of the file:
{
& quot; coinbase": & quot;& quot;,< br />" config": {< br />" homesteadBlock": 5
},
" difficulty": & quot; 0x20000",< br />" extraData": & quot; 0x",< br />" gasLimit": & quot; 0x2FEFD8",< br />" mixhash": & quot;& quot;,< br />" nonce": & quot; 0x0",< br />" parentHash": & quot; 000000000000000000000000",< br />" timestamp": & quot; 0x00",< br />" alloc": {< br />"& quot;:< br />{
" balance":& quot;& quot;
}
}
} 1234567891011213141516171819
the above code into a text file and name it genesis.json
Genesis!:
in order not to conflict with the data of the main chain, it is recommended to establish your own private chain data folder. On my computer, I built an ethdbspace as the Ethereum experimental work area on disk e, and created a privchain folder as the data storage folder of my first private chain
here, in order to facilitate management, I put genesis.json under the ethdbspace folder
open the windows command line
type the following command
geth -- dataDir & quot; E:\ EthDBSpace\ PrivChain" init " E:\ EthDBSpace\ genesis.json" 1
– the dataDir option is used to specify the data directory of our private chain. On my computer, it's E: &; EthDBSpace\ Privchain
init is the genesis command, followed by our Genesis configuration file path
after clicking enter, the execution result is as follows
at this time, genesis is complete
create an account:
in order to do experiments on the private chain, we also need to create our own account on the private chain
windows command line, type
geth -- dataDir & quot; E:\ EthDBSpace\ PrivChain" Console1
we have successfully created the world, so when we enter the client for the second time, we do not need to specify the genesis.json file path again, but directly – dataDir to indicate the private link data path
the console command is used to open the command line of geth
after clicking enter, the client will be initialized for a while. After the command prompt appears, it means that you have entered the geth console
type
personal. Newaccount (& #) in the geth command line; Your Password') 1
the personal.newaccount function is used to create an account, in which the parameter is the account password.
after clicking enter, the account creation address will be listed in green below the command, that is, the public key of the account.
we can check the account balance first, In the geth command line, type:
My = eth. Accounts [0]
eth. Getbalance (my) 12
My = eth. Accounts [0]. The purpose of this sentence is to assign the account address we just created to my variable. This can simplify the subsequent account address input. Among them, eth.accounts records the addresses of all accounts on this machine. Since we created an account for the first time, there is only one account on the computer at present. So here we use eth. Accounts [0] to extract the first account address. The eth.getbalance function is used to obtain the account balance, and the parameters are filled in the account address. The my variable here records the address of the first account
I hope my answer can help you
eth0 to awk for processing
where - F & # 39;:|< br />+'
this is a separator defined by awk and then matched with "BCAST & quot;, Take the content of the fourth column
since your command is not universal, you can't output the result here, but you should intercept the broadcast address