What are the blocks of blockchain
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
on June 1, 2020, Xinhua news agency was authorized to broadcast the "overall plan for the construction of Hainan free trade port" issued by the CPC Central Committee and the State Council, which will "actively participate in the formulation of international rules for cross-border data flow, and establish standards and rules for data rights confirmation, data trading, data security and blockchain finance" as one of the key tasks of Hainan free trade port before 2035
"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
block head: record the characteristic value of the current block
block body: actual data
The strict definition of blockchain refers to the distributed database technology that multiple nodes in peer-to-peer network jointly maintain a continuously growing list ledger constructed by time stamp and orderly record data blocks through consensus mechanism based on cryptography technology. This technical solution allows any number of nodes in the participating system to calculate and record all the information exchange data in the system in a period of time to a data block through cryptography algorithm, and generate the fingerprint of the data block for linking the next data block and checking. All participating nodes in the system jointly determine whether the record is true
blockchain is a technical solution similar to NoSQL (non relational database). It is not a specific technology, and can be implemented through many programming languages and architectures. There are many ways to realize blockchain, including pow (proof of work), POS (proof of stake), dpos (delegate proof of stake), etc
the concept of blockchain was first proposed in the paper "bitcoin: a peer-to-peer electronic cash system" by indivials (or groups) who call themselves Satoshi Nakamoto. Therefore, bitcoin can be regarded as the first application of blockchain in the field of financial payment
< H2 > [popular explanation]no matter how big the system or how small the website is, there is a database behind it. So who will maintain this database? In general, who is responsible for the operation of the network or system, then who is responsible for the maintenance. If it is wechat database, it must be maintained by Tencent team, and Taobao database is maintained by Alibaba team. We must think that this way is natural, but blockchain technology is not
if we think of the database as a book, for example, Alipay is a typical account book. Any change of data is bookkeeping. We can think of database maintenance as a very simple way of accounting. In the world of blockchain, everyone in the blockchain system has the opportunity to participate in bookkeeping. The system will select the fastest and best bookkeeper in a period of time, maybe within ten seconds or ten minutes. The bookkeeper will record the changes of the database and the account book in a block. We can think of this block as a page. After the system confirms that the records are correct, the system will record the changes of the database and the account book in a block, It will link the fingerprint of the past account book to this paper, and then send this paper to everyone else in the whole system. Then, over and over again, the system will look for the next person with fast and good bookkeeping, and everyone else in the system will get a of the whole ledger. This means that everyone as like as two peas in the system is called Blockchain. It is also called distributed account technology. P>
as like as two peas (computer) have identical accounting books, and everyone has the same rights, they will not collapse e to the loss of contact or downtime of a single person. As like as two peas, the data is transparent and everyone can see what changes are in every account. Its very interesting feature is that the data can't be tampered with. Because the system will automatically compare, it will think that the same number of books with the largest number are real books, and a small number of books with different numbers are false books. In this case, it's meaningless for anyone to tamper with his own account book, because unless you can tamper with most nodes in the whole system. If there are only five or ten nodes in the whole system, it may be easy to do so. However, if there are tens of thousands or even hundreds of thousands of nodes and they are distributed in any corner of the Internet, unless someone can control most computers in the world, it is unlikely to tamper with such a large block chain
< H2 > [elements]combined with the definition of blockchain, we think that we must have the following four elements to be called public blockchain technology. If we only have the first three elements, we will consider it as private blockchain Technology (private chain)
1, peer-to-peer network (power equivalence, physical point-to-point connection)
2, verifiable data structure (verifiable PKC system, non tampering database)
3, distributed consensus mechanism (Solving Byzantine general problem, solving double payment)
4 Game design of Nash equilibrium (cooperation is the strategy of evolutionary stability)
combined with the definition of blockchain, blockchain will realize four main characteristics: decentralized, trustless, collective maintenance and reliable database. And the other two will be derived from the four characteristics Features: open source Privacy. If a system does not have these characteristics, it can not be regarded as an application based on blockchain technology
Decentralized: there is no centralized hardware or management organization in the whole network. The rights and obligations of any node are equal, and the damage or loss of any node will not affect the operation of the whole system. Therefore, it can also be considered that the blockchain system has excellent robustnesstrustworthiness: there is no need to trust each other when participating in the data exchange between each node in the whole system. The operation rules of the whole system are open and transparent, and all data contents are also open. Therefore, within the specified rule range and time range of the system, nodes cannot and cannot cheat other nodes
collective maintenance: the data blocks in the system are maintained by all the nodes with maintenance function in the whole system, and these nodes with maintenance function can be participated by anyone
reliable database: the whole system will enable each participating node to obtain a of the complete database in the form of sub databases. Unless more than 51% of the nodes in the whole system can be controlled at the same time, the modification of the database on a single node is invalid, and the data content on other nodes cannot be affected. Therefore, the more nodes and computing power in the system, the higher the data security in the system
Open Source: since the operation rules of the whole system must be open and transparent, the whole system must be open source for the program
Privacy Protection: since there is no need to trust each other between nodes, there is no need to disclose the identity between nodes, and the privacy of each participating node in the system is protected
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
extended data:
related extension: blockchain financial application:
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
on June 1, 2020, Xinhua news agency was authorized to broadcast the "overall plan for the construction of Hainan free trade port" issued by the CPC Central Committee and the State Council, which will "actively participate in the formulation of international rules for cross-border data flow, and establish standards and rules for data rights confirmation, data trading, data security and blockchain finance" as one of the key tasks of Hainan free trade port before 2035
nowadays, the mainstream digital currencies are basically developed based on blockchain technology. Blockchain is the underlying technology of digital currency. The domestic tea based digital currency Puyin is developed based on blockchain technology.