Formation of transaction order in blockchain

1. This is not a rigid rule. It has nothing to do with blockchain. There is a relationship between the algorithm of this currency. The confirmation method of each currency is different, so this is not a rigid rule
the confirmation times of bitcoin are different from that of Ruitai coin, Laite coin and doggy coin.

2.

"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

3.

first, define the

blockchain as an open network ledger. It originated from bitcoin and is the underlying technology of bitcoin. In bitcoin transactions, all the information of transaction records will be packaged into a "block" for storage. With the expansion of information exchange, one block links with another, forming a blockchain

Second, the digital currency represented by bitcoin is a point-to-point e-cash system. Among them, every transaction will broadcast to all participants in the network, and it will be recorded in the account book after repeated confirmation, which is called "blockchain". Each participant will have his own account book. In this way, when false information occurs, it can be broken through mutual verification, so as to ensure network security

in the blockchain, every node is equal, and there is no centralized management organization. This "decentralized" feature makes the blockchain do not need to rely on a third party, its operation does not need any human intervention, and it can independently conct self verification. In addition, the network of blockchain is open to the world, and anyone can query data through the public port, so the whole system is highly transparent

In a word, blockchain is a reliable database and a reliable "account book". In the future, it will be applied in cross-border payment, securities, loans, voting, etc. For example, in cross-border payment, with the security of blockchain, you can remit money to the world anytime and anywhere, which saves a lot of intermediate links and high fees

4. Traditional transactions on the Internet need to rely on trusted third-party institutions to process electronic payment information, and both parties trust the third-party institutions However, the third-party intervention also has many disadvantages:< Br > - high transaction cost (a certain handling charge)< Br > - Privacy exposure (the third party needs to provide the information of both parties in order to verify the information)< Br > -... < br > imagine that if the third-party organization is removed and the two parties trade directly, how can the transaction take effect? The emergence of blockchain technology is to solve this problem. Blockchain is based on the principle of cryptography rather than trust mechanism, which makes the two parties reach an agreement to trade directly and publish it to all witnesses.

5. Since the implementation of the People's Republic of China Bidding Law 2011, for the first time, "electronic bidding has been encouraged by the state to encourage information networks", electronic bidding has graally emerged in the Internet plus procurement. With the green light of policy in recent years, electronic bidding technology has covered engineering construction, major equipment bidding procurement, government procurement, drug procurement and other fields< Since br />2013, the state has been promoting electronic tendering and bidding in the layout, and has promulgated important rules and regulations such as the electronic bidding and bidding system and the "Internet plus" bidding and procurement action plan (2017-2019 years). Hebei province seriously implements the national deployment and requirements, takes the implementation of electronic bidding as a key task of comprehensively deepening the reform, and is listed in the provincial key reform project in 2017. Hengshui, as the only pilot city, takes the lead in carrying out the whole process of electronic bidding in Hebei Province< On April 9, 2019, the Department of housing and urban rural development of Guangxi Province, the national development and Reform Commission and the Administration Bureau of organ affairs jointly issued the notice on continuing to promote the electronic bidding of housing construction and municipal infrastructure projects (Draft for comments)
on May 19, 2019, the general office of the State Council transmitted the guidance on deepening the integration and sharing of public resources trading platform issued by the national development and Reform Commission, One of its main goals is to "fully implement the electronization of public resources and realize the online real-time supervision of the whole process of public resources transactions" by 2020....
on May 30, 2019, the decision of the Standing Committee of Hebei Provincial People's Congress on strengthening the supervision and management of the construction market was deliberated and adopted by the 10th meeting of the Standing Committee of the 13th Hebei Provincial People's Congress and implemented on June 1, On June 15, 2019, the general office of Guangzhou Municipal People's government officially printed and issued the implementation plan for deepening the reform of the bidding system of construction projects in Guangzhou (hereinafter referred to as the plan), and proposed nine reform measures in view of the new situation and new problems in the current bidding work, To further deepen the reform of the bidding and tendering in Guangzhou construction project, China's tendering and bidding public service platform in from July 18th to 19th
2019 held a two day collaborative promotion of Internet plus bidding technology innovation achievements in Beijing. The conference mainly focused on the three themes of "CA code scanning mutual recognition and sharing", "system network, big data, security" and "blockchain", CFCA mobile electronic authentication: to build the whole process security guarantee of handheld electronic bidding....
on July 24, 2019, the first anniversary of the whole process electronic bidding in Hengshui, Hebei Province....
the above electronic bidding pilot and policy promotion have made the electronic bidding develop rapidly in the whole country, and become an important platform for engineering construction, government procurement, information technology and so on Mineral trading and other fields of the mainstream bidding mode. Electronic bidding is closely related to the development of information technology all over the world. With the rise and development of e-government, commerce and project management, electronic bidding has become the main means of bidding, which is an inevitable development trend
looking forward to the future, how will electronic bidding develop
Future Prospects: the government, large state-owned enterprises and third-party institutions will work together to build a benign ecological environment for electronic bidding
(1) as the main three parties involved in the E-bidding market, the government, large state-owned enterprises and the third-party E-bidding institutions can only build a benign ecological environment of the instry and build an efficient, open, fair and just bidding instry pattern through win-win cooperation
(2) as the main body of the public resources trading center, the government must perform the supervision and management responsibilities, accelerate the reform of the separation of the three networks, separate the administrative supervision platform, public service platform and electronic bidding trading platform, distribute different functions to the most professional people, and guide the market capital to actively participate in, which can effectively prevent insider trading, Improve the overall efficiency and transparency of the instry
electronic bidding is a bidding activity completed in the form of data message. Generally speaking, it means that some or all of the paper documents are discarded, and the business processes such as bidding, bidding, bid evaluation, contract signing, and even the whole process are electronically realized by means of computer and communication technology
there is a special definition of bidding in China, and bidding activities are subject to the bidding law and its implementation regulations. For electronic bidding, the national development and Reform Commission, the Ministry of instry and information technology, the Ministry of supervision, the Ministry of housing and urban rural development, the Ministry of transportation, the Ministry of railways, the Ministry of water resources and the Ministry of Commerce jointly formulated the "electronic bidding method" and its annex "technical specification for bidding system" The promulgation of the measures for electronic tendering and bidding will provide unified standards and legal basis for the practice of electronic tendering and bidding in various regions and departments, and make it develop in a more standardized and unified direction
it should be pointed out that the online bidding operation of each trading platform will be slightly different. In actual operation, we also need to understand the specific process of a specific trading platform. Do specific analysis of specific problems
on the issue of E-bidding, what are the advantages of E-bidding
e to the existence of E-bidding, the traditional bidding methods are suffering from the test of the times, and the future prospects become uncertain and unpredictable. With the strong support of national policies for E-bidding, E-bidding has been widely used in engineering bidding, e-procurement, government procurement and other instries. Following the pace of China Bidding network to analyze the advantages of electronic bidding
combined with the views of experts and instry insiders, several advantages are summarized:
1. The bidding instry is full of corruption, and transparency is more important. All information of bidding projects, including procurement, bidding notice, bid winning announcement, etc., are publicly released on the electronic bidding system to realize the open, fair and just principles of bidding activities
2. Rece the cost and improve the efficiency
using the electronic bidding system, the cost is lower. Save manpower and material costs
3. Detailed analysis of bidding documents and locking of illegal clues
the system automatically records the user's hardware characteristic code, tool software, pricing software identity code, etc., binds the information with the bidding documents, and concts identification, comparison and detailed analysis of these information that should not be the same ring bid evaluation, which can effectively lock the illegal clues< In the traditional bidding activities, the bidding data can only be managed by manual registration or re entry, which not only wastes manpower e to repeated labor, but also provides effective data support for government regulatory departments to grasp the instry development status and trend in real time and make scientific macroeconomic decisions, Moreover, because the data update is not synchronized, the data association is poor, resulting in the disconnection between business and management. The electronic bidding platform directly collects relevant information and data in the business process, which is closely related and has strong linkage effect. The preciseness of the bidding process ensures the accuracy and reliability of the data information. Through the accumulation of a certain period of time, the formation of the bidding resource information database is concive to the analysis and summary of the bidding and procurement work of the bidding agencies, and improve the level of business management. At the same time, it provides effective data support for the government regulatory departments to grasp the current situation and trend of the instry development in real time and make scientific macroeconomic decisions
5. Keep the bidding information confidential, increase the difficulty of breaking the rules, and detect and curb the bidding collusion
through the application of online downloading bidding announcement, online bidding registration, online downloading bidding documents, online answering questions, online payment and other functions, the handling situation of each node can be quickly fed back through the SMS platform. In this way, the information of bidders is in a highly confidential state before the deadline of bidding, which makes it difficult for those who intend to collude with each other to master the relevant information
6. Set up multiple rounds of inspection to curb the directional rejection of bids
conct comprehensive proofreading and inspection on the integrity, conformity and accuracy of the contents of the bid documents in multiple links such as bid preparation, upload and evaluation, so as to prevent the judges from choosing the directional rejection of bids with the intention of bid evaluation, so as to cut off the interest relationship between the judges and some bidders< (1) the online bidding system is supported by the enterprise credit database. Once confirmed, the fraulent enterprises will be listed in the blacklist database and publicized online. The system will automatically close their information channels, and they will not be eligible for online registration in future bidding activities. This undoubtedly increases the illegal cost of bidding enterprises, Make bidding enterprises cherish bidding credit record more
(2) through the information feedback from the bidding units to the construction units, the malicious default of the construction funds of the construction units can be effectively curbed, which helps to improve the integrity construction of the construction units; Improving the evaluation system of judges is concive to supervising the professional ability and professional ethics of judges
the Internet has profoundly changed people's way of work and life, and has become a new form of business. Electronic bidding is the core application of "Internet plus bidding", and will graally become the mainstream mode of China's bidding field.