Complete solution of blockchain
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 kind of technology, which solves the core "trust" problem in the market economy and reces the trust cost between strangers to a very low level
there is one crucial thing in the market economy, which is "trust". Without trust, no deal can be established. When you go to LAICHANG to buy vegetables, if you don't believe that the pesticide content in vegetable is up to the standard, you won't trade with that dealer; If you buy a bottle of water in a small shop, the clerk will not sell you the water if he doesn't believe that the money you give is real
the traditional small-scale peasant economy is acquaintance economy, and the transaction scale is limited to people who are familiar with each other nearby. If an acquaintance deceives you, he will lose your social relationship and damage his reputation in the whole circle of acquaintances. We believe that acquaintances are less likely to cheat us than strangers
therefore, once we are beyond the scope of acquaintances, we need to use a high cost to identify whether a stranger will cheat me and how to avoid the risk of being cheated. This situation will hinder the transaction and restrict the transaction
in addition, different races, nationalities, cultures, religious beliefs and so on will naturally have this kind of trust problem
in the market economy, why can there be so many transactions between strangers? Because of the birth of a new mechanism to solve the problem of trust in strangers
so far, the most important mechanism to solve the trust problem is the "trust intermediary" organization and mode
as long as you and strangers trust a third-party organization, the trust problem between you can be solved through this third-party organization
this third-party organization, we call it trust intermediary. Both the government and the bank are trust intermediaries
you can sell the goods you have worked hard to proce to a stranger in exchange for a stack of RMB banknotes. It's because the credit of the note issuing bank and the guarantee of the authority of the government guarantee the currency value and effectiveness of the banknotes. Otherwise, sell things, in exchange for a few ordinary paper, who would like to
in the era of global village and Internet, the people who buy your things may be strangers who will not meet and thousands of miles away. Trust is lower, so Alipay assumes the role of trust intermediation. Buyers first pay the goods to Alipay's account. When they receive the goods, they confirm that they are OK, then they agree to sell the goods to the seller. Taobao and other e-commerce have been booming rapidly in just over ten years
trust intermediary is in a central position in the transaction system. All transactions should solve the trust problem through it
However, the cost of trust intermediary itself is often hugeas a trust intermediary, how much transaction tax does the government charge each year? What is the most profitable instry? Financial services. The annual profits of Alipay's ant suit are over ten billion. p> What does this mean? Both sides of the market actually pay a huge trust cost
if there is any way to cancel or greatly rece the trust cost, the transaction cost of the general public can be reced, and the profits can be greatly increased
so in the Internet era, blockchain technology is on the stage
it allows the trading party to get rid of the intermediary, solve the problem of trust among strangers, and greatly rece the cost of trust
the blockchain can be expanded on a large scale, the data is open and transparent, the data of each client is consistent, and even if some clients are destroyed, the data security will not be affected. These highly reliable technical features can solve the trust problem of strangers with low cost
this technology can be extended to all fields that can be digitized, such as digital currency, payment and clearing, digital bills, proof of rights and interests, credit reference, government services, medical records, etc
in the medium and long term, blockchain will be a revolutionary technology, which will bring about great social changes like the existing Internet, and has great investment value and money making opportunities
in the future, the companies that can combine blockchain with different scenarios to promote applications may be the next group of bat, the next Google, Microsoft and apple
as the first practical application of blockchain technology, bitcoin has been widely accepted and used all over the world. Millions of users and tens of thousands of merchants have accepted the payment of bitcoin as a digital currency, and the exchange value of bitcoin as a currency is growing. Even e to the consensus that the total amount is fixed and the long-term value is bullish, bitcoin has become a hedge asset similar to gold, and the price has skyrocketed
in a village, a spent 3000 yuan to buy a cow of B, how to record this account
so a and B found a mutual trusted C to record the account, but later a and C colluded and did not admit that a had bought B's cattle, so the deal became rough and disputes continued
later, B had another cow. Of course, B didn't sell it to a this time, because a had no credit, so he gave it to d. This time, instead of looking for witnesses, they went to the whole village to roar after the transaction. B said Wang Erhua paid 3000 yuan to buy a cow from me, d also went to the whole village to shout that I paid 3000 yuan to buy a cow from B, so there were many people in the village to record the transaction. In this way, there will be no bad debts, which is called decentralized and distributed accounting
here comes the problem
when you yell, are the villagers willing to charge for you, just because you have a big face
therefore, the first person to record accurately will get some bitcoin rewards
someone asked, what if two people finish the first record at the same time
in order to avoid this problem, it is necessary to set rules, for example, to answer a question first, or to record with feet, and it must be written in block letters. If you set a series of rules, there will not be many firsts
in the network, there are a lot of transactions going on every day, and there are also many people recording, and finally they get the reward of bitcoin. This process is the legendary mining
Mining requires a lot of equipment. We call these computer equipment mining machines
in this way, all the processes are in one system. The system will encapsulate the data every 10 minutes to form a box full of data, which we call blocks
with the continuous generation of blocks, they are linked together to form a blockchain.
in other words, blockchain solves the problem of trust and security
using ordinary computer CPU does carry out bitcoin mining. Because bitcoin mining has formed a huge instry all over the world, ordinary computer is difficult to dig bitcoin. You need to buy expensive and professional bitcoin ASIC mining machine and join bitcoin miners' organization to dig bitcoin, that is, join the mine to dig Mining
bitcoin mining machine market has a high threshold. It is suggested that new players who want to dig for gold should be cautious.
at present, bitcoin mining needs professional ASIC mining machine. For example, Avalon mining machine, the mainstream of the market, is said that Avalon's fourth generation 28nm process chip, that is, chip flow, is expected to focus on the fifth generation 16nm process chip