Blockchain technology Shunfeng
blockchain refers to the technical solution of collective maintenance of a reliable database through centralization and distrust in the past, and it is a technical way for the whole people to participate in bookkeeping. Previous bookkeeping methods were all centralized and needed centralized intermediary, whether it was traditional government, financial institutions, notarization institutions or emerging e-commerce platform and online payment platform
in economic hypothesis, information is sufficient. In fact, it is precisely because of insufficient information that there are very large intermediaries. The existence of intermediaries increases the transaction cost and raises the transaction threshold. In essence, blockchain technology is a large-scale collaboration tool. It makes direct value transfer possible by using pure technology for the first time, and continues the trend of Internet decentralization and disintermediation. Disintermediated blockchain technology will greatly subvert the information intermediary instry
blockchain technology is the basic technology for building bitcoin data structure and encrypted transmission of transaction information, which realizes the issue and transaction of bitcoin. The core of blockchain technology is that all the current participating nodes jointly maintain the transaction and database, so that the transaction is based on the principle of cryptography rather than trust, so that any agreed parties can directly carry out payment transactions without the participation of a third party
technically, a block is a data structure for recording transactions, reflecting the capital flow of a transaction. In the system, the transaction blocks are connected to form a main chain, and all the nodes participating in the calculation record the main chain or part of the main chain
a block contains the following three parts: transaction information, hash formed by the previous block and random number. Transaction information is the task data carried by the block, including the private keys of both parties, the number of transactions, the digital signature of electronic currency, etc; The hash hash formed by the previous block is used to connect the blocks and realize the sequence of past transactions; Random number is the core of the transaction. All nodes compete to calculate the answer of the random number. The node that gets the answer the fastest generates a new block and broadcasts it to all nodes for updating, so as to complete a transaction.
From the perspective of technology and architecture, I will tell you my understanding of blockchain in common language
what is blockchain? In a word, blockchain is a storage system. To be more specific, blockchain is a distributed storage system without an administrator and each node has all the data
What are the common storage systems like
first, how to ensure high availability
the common storage system usually uses "rendancy" to solve the problem of high availability. As shown in the figure above, if the data can be copied into several copies and rendant to multiple places, high availability can be guaranteed. The data in one place is hung, and there is data in other places. For example, the master-slave cluster of MySQL is the same principle, and the raid of disk is also the same principle
two points need to be emphasized in this place are: data rendancy often leads to consistency problems
1. For example, in the master-slave cluster of MySQL, there is actually a delay in reading and writing, which means there is a inconsistency in reading and writing in a short period of time. This is a side effect of data rendancy
The second point is that data rendancy often reces the efficiency of writing, because data synchronization also consumes resources. If you add two slave libraries, the write efficiency will be affected. The common storage system is to use rendancy to ensure the high availability of dataso the second question, ordinary storage system, can write more
the answer is yes, for example, take this graph as an example:
in fact, MySQL can do a master-slave synchronization of al masters, master-slave synchronization of al masters, two nodes can be written at the same time. If you want to do a multi room multi live data center, in fact, multi room multi live data synchronization. What we should emphasize here is that multi-point writing often leads to the consistency problem of writing conflicts. Take MySQL as an example, suppose that the attribute of a table is self incrementing ID, then the data in the database is 1234 now. If one of the nodes writes and inserts a piece of data, it may become 5, and then these 5 pieces of data are synchronized to another master node, Before synchronization, if another write node inserts a piece of data, a piece of data with self incrementing ID of 5 will be generated. Then, after the generation, synchronize to another node, and the synchronized data will conflict with the two local 5's after it arrives, which will lead to synchronization failure and write consistency conflict. This problem will occur in the case of multi-point writing
how to ensure consistency in multi-point writing
the reform "Swan class" gives you more technical work
If bitcoin represents blockchain version 1.0, it proves to the world that digital currency can be realized. Then Ethereum represents blockchain version 2.0, which lets you know more about the play of blockchain, decentralized applications and smart contracts. In 2018, blockchain will enter the stage of 3.0, application and scenario landing will be the core of blockchain, and blockchain based applications in various instries will spring up, which will be the early dividend period of the last stage of blockchain development. The demand for talents driven by the application of blockchain technology has become increasingly large. Blockchain technical talents have become the new professional talents, which are highly competitive, and also have enviable high salaries
whether to form a meaningful large-scale consensus: one of the outstanding advantages of blockchain is that it can effectively form a large-scale consensus by opening account books and notifying the whole network. At present, there is no need to form a network wide consensus for many projects. Some projects are just for crowdfunding and token issuance. The blockchain consensus of projects is meaningless. Does this model have network effect: network effect means that a project will become more and more valuable with more and more users of the project, because the value of the project is not in the users themselves, but in the connection network between users. Bitcoin is a typical example. The more user nodes there are, the more links between nodes will grow exponentially, and the whole ecosystem of bitcoin will be more valuable
of course, in addition to these points, there are many basic principles to judge the project, such as effective incentive mechanism, strong team, project solving pain points, and so on
in the express logistics instry, there are blockchain companies in China, such as Walton chain
last year, Walton chain and cargo bag (Xiamen) Technology Co., Ltd. reached a strategic cooperation to help them improve their logistics solutions through the "RFID + blockchain" technical solution of Walton chain, and link the data of cargo bag in all aspects of its logistics turnover, such as the layout of the read-write system of key nodes such as in and out of warehouse, receiving and taking goods, when the objects pass any link, All the data can be read by RFID reader, and the corresponding behavior can be transformed into data, which can be uploaded to the blockchain. Users can trace the whole process of logistics with one click
the four business scenarios that can be implemented in the real environment are suitable for the application of blockchain technology
Scene 1: Express insurance
around the insurance scene, express companies carry out commodity transportation, insurance companies provide commodity insurance, merchants provide commodity sales, sellers purchase insurance services, and the government carries out instry supervision
then, what should be recorded on the blockchain? There are several key points, such as the logistics details, accounts, identities, claims and other reference data of commodities are recorded on the blockchain
insurance is the concept of contract. When the customer signs for the package normally, the account claims will be automatically triggered, the contract will end normally, and the premium will be automatically cleared. If there is a problem or lost part, the insurance company's claim process will be triggered
Scene 2: public express
for public welfare activities, such as "one cent" activities, one cent of the cost of each public parcel is donated to the account of public welfare organizations. In this scenario, the express company still undertakes the transportation of goods, the public welfare organizations provide the implementation of public welfare activities, and the poverty alleviation businesses provide the sales of public welfare poverty alleviation goods
then what is recorded in the blockchain is the logistics details of the goods. After the package is signed, it will be recorded on the blockchain and automatically trigger the transfer from the public welfare account of the logistics company to the account of the public welfare organization. When the public welfare activities are over, the whole process is open and transparent, avoiding the public's distrust of social public welfare activities
Scene 3: share the instry blacklist
the blacklist of express delivery practitioners is still dominated by offline mode at present. We hope that through the blockchain technology, each company can record the blacklist of employees on the blockchain, and other companies can also query, and the data can not be modified, and can be traced back to the information such as which company this person did what kind of inappropriate behavior
Scene 4: Supervision of security incidents in postal delivery channels
many express companies will install security inspection machines, and the government also wants to know whether each logistics company has any potential transportation security incidents. Through the mode of Distributed Accounting, each express company can record the effective information of the security event on the blockchain when there is a security event, so that the regulatory authorities can monitor in real time and can not tamper with it
the contents of this article do not constitute any investment suggestions. There are risks in the market and investment should be cautious
and you won't, you can go to the backup person to watch the video. There are many excellent videos of lectures given by Cowman lecturers, you can try them
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data
NMC coin, also known as domain name coin, is a distributed domain name system based on bitcoin technology, which has the characteristics of security and non censorship. There are no cheaters. However, e to the relative lack of supervision, digital currency is easy to be pulled up or sold, so it may become rich overnight, or it may lose all the principal overnight. This is the general nature of digital currency, not just NMC currency
the connection is that CNM is developed based on blockchain technology.