Blockchain broadcasting
"blockchain is equivalent to this account book, and the block is equivalent to a page of this account book. The information carried in the block is the transaction content recorded on this page. The blockchain is block by block, and each block is filled with transaction records and connected together to form a chain, which is called blockchain. "
take bitcoin as an example, there is a "power race" every ten minutes to compete for the right to charge. It's like saying that you have a lot of calculation power, just like your muscles are stronger and more capable of fighting. Everyone will convince you to keep this account, that is, the right to write a block (note that it is not the content in the block) to the general ledger of the blockchain. However, it should be noted that computing power can only determine the probability of winning the competition. For example, there are several lotteries in total, and those with more computing power can buy more to improve the winning probability. However, those who buy more may not win the lottery in the end.
blockchain is a data block chain guaranteed by such computing power. Starting from the first block, each block collects data according to certain rules, and then attaches a value to these data, so that the result of the formed data block after similar one-way function calculation falls into a certain range. By estimating the computing power of the whole network and the size of the control result range, the data blocks that meet the requirements can be found in a long enough time. This calculation result will be included by the next block, and the chain data structure formed in this way is called blockchain
each small ledger is called a block, and each different blockchain protocol (generating different cryptocurrency) will specify the size of each block (the initial bitcoin is 1m). The ledger constitutes a block, the block constitutes a chain list, and the block header contains the hash value of the previous block, which is the blockchain. In this way, no one can modify the content or exchange the order at will. If you do, it means you need to recalculate all the special numbers
regulations allow everyone in the world to build blocks. Every person who builds a new block (finds this special number - sha256 value has 30 zeros) can get a reward. For this part of people (miners) who build a new block:
1. There is no sender information, There is no need to sign
2. Each new block will add a new virtual (encrypted) currency to the whole currency
3. The process of building a new block is also called "mining": it requires a lot of work and can inject new currency into the whole economy
4. The work of mining is: receiving transaction information, building blocks, broadcasting blocks, Then get new money as a reward
for each miner, each block is like a small lottery, and everyone is trying to guess the number quickly until a lucky person finds a special number, so that there are many zeros at the beginning of the hash value of the whole block, and they can get a reward. I remember a Zhihu respondent gave an image analogy. Blockchain is like a king with a beautiful daughter (block). Many young people are looking forward to it. The king's method is to give a very difficult topic for all young people to calculate (learning to change their lives), Who can calculate quickly (or be lucky in the process of calculating the hash value) will be able to win the beauty
for users who want to use this system to collect and pay, they don't need to listen to all the transactions, but just listen to the blocks broadcast by the miners, and then update them to their saved blockchain
"block" can also be imagined as a box, There are some digital currencies and a small note in the block, on which the only transaction information generated in the past ten minutes is recorded, such as "small a transferred to small B100 yuan"; Of course, this piece of information must have been encrypted to ensure that only small a and small B (through the key in their hands) have the ability to interpret the real content
after this magical block was created, it was soon buried underground. Where is it buried? No one does not know that all computer nodes need to participate in digging three feet before it is possible to find (find an effective workload proof). Obviously, this is an event with huge workload and random results. However, for the computer node, once the block is g out from the ground, it will get the valuable digital currency in the block, as well as the tip paid by small a in the process of "small a transferred to small B100 yuan". At the same time, for this node, only he has the right to truly record the contents of the note, which is an honor, while other nodes can only use its , a without digital currency blessing. Of course, there are some other special things about this magical block.
the process of computer nodes digging out blocks from underground is called "mining". As I said just now, this is a huge workload, a lot of luck and a lot of profits. A node on zhangheng road in Pudong New Area of Shanghai, China, suddenly jumped out and said excitedly, "I've g the block! The little notes inside are all valid! The reward belongs to me! ". Although Zhang Heng Road node has got digital currency at the moment, for other computer nodes, because it also involves some other interests, they will not choose to believe what Zhang Heng Road node says by default; Based on the principle that strangers do not trust each other, they take the so-called block () g by Zhang Heng Road node, and start to check whether the small note information in the block is true and effective, etc. In the world of blockchain, nodes check the accuracy of the small note information, or indirectly or directly judge whether the node that successfully digs out the block is lying How to define the true and effective information of a small note will be explained later, but I won't go into details here. In the verification process, each node will directly express their identification (accurate) and attitude towards zhangheng road node through the following two behaviors: stop half or even 80% of the mining process; Add the block () g out by zhangheng road node to the end of its own blockchain. You can be a little confused: if you stop mining, you may have done 80% of the mining work. Then 80% of the previous work is in vain?! Then, what the hell is at the end of the blockchain? For the first puzzle. I want to say that what you said is right, but there is no way. The reality is so cruel. Even if 80% of the work is done, you have to give up. The 80% of the work can be regarded as useless, absolutely damaging the wealth and the masses. The second puzzle is, what is the ghost at the end of blockchain and blockchain? Here, it is not clear in advance, but you can simply imagine: blocks are generated and g out periodically, and a computer node may have executed "take blocks from others" n times in advance; The process of "checking the validity of small notes" must have stored n blocks on its own node, and these blocks will be arranged in a chain in order of time. Yes, this chain is what you always think of as the blockchain. If you still can't understand, it doesn't matter. There will be many opportunities for in-depth study later in the article
go into the more microcosmic world of the block and have a look at what the little note really is, how it came into being and its mission all its life: when initiating a transaction, the initiator will receive a little note, and he needs to write the transaction record, such as "stealing transfer to a piece of RMB 340" on the paper. It's amazing that when it's finished, on the back of the note, the transaction record will be automatically formatted to at least contain the two important fields of "input value" and "output value"“ Input value is used to record the effective source of digital currency, and output value is used to record the object to which digital currency is sent. The newly created note is immediately marked as an "unconfirmed" note. Small pieces of paper that are successfully g out of the ground and eventually connected to the blockchain are initially marked as "valid.". If the valid slip is used as the input value of other transactions, the valid slip will soon be marked as invalid. Due to various reasons, the block is disconnected and discarded from the chain, and the small notes once marked as "valid" in the block will be re marked as "unconfirmed". There is no concept of account balance in the blockchain. The digital asset you really own is actually a piece of transaction information; Get the balance in your digital wallet by simple addition and subtraction. The above 1, 2 and 3 are just the knowledge points forced to you at the beginning. Some of the descriptions may be a bit confusing, which makes you feel confused. Only by understanding the whole blockchain can you have a more comprehensive understanding of the mystery
block capacity. Bitcoin specifies that the block capacity is 1m when it is created, or in the source code. The reason why it was originally designed as 1m is, on the one hand, to prevent DoS attacks. On the other hand, when Zhongben Cong created the blockchain, the capacity was 32m. However, he changed the block capacity to 1m through a humble commit like "clear up". In order to prevent the volume of the blockchain from growing too fast, he added some mystery to the problem of block capacity. The capacity of 1m means that the maximum number of transactions processed by bitcoin is about 2400 (the size of 486882 block 1034.39 is very close)
to put it bluntly, blockchain is a small book for distributed bookkeeping, a tool for bookkeeping, and based on cryptography and cryptography technology, once data transactions are recorded in the book of blockchain, data can not be tampered with and denied. The Internet is the transmission of value, and the blockchain is the transmission of trust. Under the premise of blockchain technology as a credit endorsement, each node in the blockchain changes from a single center to a unified multi center with multi-party participation, which can achieve transaction transmission without the participation of a third party organization and improve the efficiency
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.
what is blockchain? Blockchain technology is a way for the whole people to participate in bookkeeping. There is a database behind all the systems. You can think of the database as a big ledger. So it's very important who keeps this account book. At present, whose system will keep accounts, wechat's account book is Tencent's account book, and Taobao's account book is Ali's account book. But now in the blockchain system, everyone in the system can have the opportunity to participate in bookkeeping. If there is any data change in a certain period of time, everyone in the system can conct bookkeeping. The system will judge the person who has the fastest and best bookkeeping in this period, write the content of his records into the account book, and send the content of the account book to all other people in the system for backup. In this way, everyone in the system has a complete account book. This way, we call it blockchain technology
what is blockchain? For example, in our daily online shopping, the money paid after placing an order for the selected goods will first be paid to the third-party payment platform, and the third-party payment platform will only pay the money to the seller's account after the seller delivers the goods to the buyer to confirm the receipt
when a transaction occurs between the buyer and the seller, the system will broadcast the transaction information between them. The person who receives the message will record the transaction after confirming that the message is correct, that is, the person who receives the message has made a data backup for the transaction
just like Zhang Ergou bought an inflatable doll on the Internet, the system would hold a loudspeaker and shout in the village: "Zhang Ergou bought an inflatable doll"“ After hearing the broadcast, the villagers took out a small notebook and wrote it down. Zhang Ergou bought an inflatable doll. Here, the recorded information is like a data backup for this transaction. Back to the current online shopping, if Zhang Ergou's order problems, Alipay system failure can not record this transaction, then Li Goudan's money is not white. On the blockchain, if there is a problem with the order, because in the early stage, the system broadcast everywhere that Zhang Ergou bought an inflatable doll with a loudspeaker, so countless people recorded the transaction information, and there would be no system failure to record the transaction records
what is blockchain? At present, blockchain technology is very popular, especially in the financial sector. Ant finance, LETV finance, Wanda, Ping'an and Minsheng have successively tested blockchain projects, and eurocrowdfunding is in the forefront of using blockchain technology
blockchain is a large-scale and decentralized economic organization mode realized by a group of technologies
bitcoin is a practical embodiment of blockchain technology, which is more accurate than the former
in fact, whether it's blockchain or bitcoin, people are more concerned about the coin itself, which coin makes more money and how to join it
what is blockchain? Blockchain has attracted wide attention because it has changed the original economic organization mode in many fields. For example, in the process of currency issuance and circulation, cryptocurrency makes the core role of the banking system decline, and the organization mode among the central bank, commercial banks and users has changed significantly; In Ethereum erc20 token system, blockchain has completely changed the organization mode among securities issuers, participants at all levels and regulators. Although it brings some problems, it also improves the efficiency of securities issuance and circulation
people are now exploring the application of blockchain in various fields of economy. In essence, they are looking for new ways to use blockchain to adjust or innovate the original economic organization mode of enterprises, instries and regions, and to rece costs and improve revenue. As an economic organization mode, blockchain can be extended downward to its implementation technology, and upward to its impact on social organization and social consciousness, which makes it easier to understand the complex social impact brought by blockchain.
1. Regularly clean the st in the computer, turn off the computer, open the chassis, use a hair dryer and blow with cold air< At ordinary times, 360 guard, Jinshan guard and other tools should be used to clean up the system garbage and temporary files generated by the Internet, and check and kill malicious
Italian software
3. The computer configuration is poor, so try to set the virtual memory as large as possible, and install anti-virus software with less resources, such as NOD32, or only one
auxiliary anti-virus software
4. Try to set the IP to static IP, which can rece the startup time of the computer
5. Don't put too many files and icons on the computer desktop, which will slow down the reaction of the computer. Try not to install the software on disk C
6. Regularly defragment the disk. Open the drive of my computer to defragment - properties - tools
select the disk to be defragmented. Open the "disk defragmenter" window - Analysis - defragmentation - the system will start to defragment
.