The nature of blockchain

1.

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)

< H2 > [Characteristics]

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 robustness

trustworthiness: 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

2. In the blockchain system, it is necessary to describe the ownership, protect the ownership, store the transaction data, distribute the ledger to an untrusted environment, add transaction records to the ledger, and decide which ledger determines the truth
bitcoin is a typical blockchain system, which can be studied carefully

3.

1、 Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies

blockchain is an important concept of bitcoin. It is essentially a disintermediated database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains the information of a bitcoin network transaction, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

2. Application

1. Art instry

ascribe enables artists to declare ownership by using blockchain technology, issue numbered and limited edition works, and target at any type of digital form of art. It even includes a trading market where artists can buy and sell through their websites without any intermediary services

In recent years, bitproof is the most advanced application in many document time stamp applications, which will make the traditional notarization method become the past. Bitproof offers more services than free versions including blocksgin and originstaemp, including one for intellectual property. Interestingly, bitproof recently cooperated with an it school in San Francisco to put their students' academic certificates on the blockchain, completely redefining how to handle and use diplomas and student certificates

Development instry colu is the first enterprise to allow other enterprises to issue digital assets. They can "token" all kinds of assets to impress many people. Although the free bitcoin wallet couperparty also allows simple tokens to be issued and traded among other wallet holders, the tokens of colu can be set with various states and types, can be detached from or returned to the system, and can be stored on BitTorrent's network when the data stored on the blockchain is too large

4. Real estate instry

they plan to make the whole instry chain process more modern and solve various problems faced by everyone when participating in real estate, including naming process, land registration, agency, etc

5, Internet of things

a possible application scenario is: generate corresponding behavior through transaction, assign address to each device, inject a certain fee into the address, and perform relevant actions, so as to achieve the application of Internet of things. Similar to: PM2.5 monitoring point data acquisition, server leasing, webcam data call, DNS server, etc

6. Insurance instry in the past two years, the hottest topic in the field of science and technology can not be separated from blockchain technology. This underlying technology, born out of bitcoin, has proved its highly secure and reliable architecture and algorithm design with more than seven years of stable operation. At the same time, with innovative technologies such as distributed ledger and smart contract, it has opened up a huge imagination space for instrial upgrading of many instries. Some instry experts even predict that blockchain technology will set off the second Internet revolution

extended materials:

in 2008, Nakamoto proposed the concept of "blockchain" in the white paper on bitcoin, and established bitcoin network in 2009, developing the first block, namely "Genesis block"

the shared value system of blockchain was first imitated by many cryptocurrencies, and improved in workload proof and algorithm, such as equity proof and scrypt algorithm. Subsequently, the blockchain ecosystem has been evolving all over the world, with the emergence of ICO for the first token sale, Ethereum for smart contract blockchain, "asset token sharing economy with light ownership and heavy right to use" and blockchain countries

at present, people are using this shared value system to develop decentralized applications (DAPP) in all walks of life, and build decentralized autonomous organizations and decentralized autonomous communities (DAS) around the world

4.

A: the basic characteristics of blockchain

I. decentralization
blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage

Second, openness

the foundation of blockchain technology is open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent

Third, independence

based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention

Four, safety

as long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily controlled and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes

5. Anonymity

unless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information transmission can be anonymous

5.

Pyramid selling is harmful to family, society, indivial mind and social stability

Deng Wanhong, deputy director of Shenyang Public Security Bureau, said on the 18th that Shenyang police have successfully cracked a major pyramid selling case involving 25 provinces, autonomous regions and cities through continuous efforts. Up to now, the police suspect 24 suspects in criminal detention, and seized 364 million yuan in cash. On September 15 this year, a clue to the implementation of illegal pyramid selling activities entered the sight of Shenyang police. According to the preliminary investigation of Shenyang Public Security Bureau, the gang involved a large number of people. In September and October this year alone, it developed nearly 100000 people, involving 25 provinces, autonomous regions and cities such as Liaoning, Beijing and Tianjin. According to the preliminary statistics, the amount involved in the case reached 600 million yuan. The gang is eligible for membership by paying a membership fee of 3900 yuan per person. At that time, it will get an annual income of no less than 150000 yuan. At the same time, each member of the development of a new member, you can get a bonus of several hundred yuan

In short, the existence of MLM organizations not only threatens families and indivials, but also affects social stability

6. Little knowledge of blockchain: what are the characteristics of blockchain
nowadays, blockchain has become an area of public concern, and many enterprises have already studied the implementation of this technology. However, there are still a large number of people who are not familiar with the relevant concepts of blockchain technology. Recently, Viking Research Institute and think tank a jointly proced the blockchain instry dictionary. Bianews, as a media partner, has been authorized to popularize the knowledge of blockchain every day
today, bianews will bring you a little knowledge of blockchain. (2) the characteristics of blockchain
1. Anonymity / anonymousness because the data exchange between the nodes of the blockchain follows a fixed and predictable algorithm, the blockchain network does not need to be trusted and can exchange data based on address rather than personal identity
2. Autonomous / autonomous blockchain adopts consensus based mechanism, which enables all nodes in the whole system to exchange data, record data and update data freely and safely in a de trusted environment, without any human intervention
3. The open / openness blockchain system is open, and any node can have the total account book of the whole network. Except that the private information of the parties directly related to the data is encrypted by asymmetric encryption technology, the data of the blockchain is open to all nodes, so the information of the whole system is highly transparent
4. The digital nature of programmable / programmable distributed ledger means that blockchain transactions can be associated with computing logic and are programmable in nature. Therefore, users can set algorithms and rules to automatically trigger transactions between nodes
5. The traceability / Traceability blockchain stores all the historical data after the genesis block through the block data structure, and any data on the blockchain can be traced back to its origin through the chain structure
6. Tamper proof / after the information of tamper proof blockchain is added to the blockchain through consensus, it is jointly recorded by all nodes, and the mutual correlation is ensured through cryptography, so the difficulty and cost of tampering is very high
7. The collective maintenance / collectively maintain blockchain system is jointly maintained by all the nodes with maintenance function. All nodes can query blockchain data and develop related applications through open interfaces
8. No license / permissionless no license means that all nodes can request to add any transaction to the blockchain, but only if all users think it is legal.

7.

Characteristics of blockchain

one of the four characteristics of blockchain: tamper proof

the most easily understood characteristic of blockchain is tamper proof

tamper proof is based on the unique account book of "block + Chain": the blocks with transactions are added to the end of the chain in time order. To modify the data in a block, you need to regenerate all blocks after it
one of the important roles of consensus mechanism is to make it almost impossible to modify a large number of blocks at high cost. Take the blockchain network (such as bitcoin and Ethereum) with workload proof as an example, only with 51% of computing power can all blocks be regenerated to tamper with data. However, the destruction of data is not in line with the self-interest of players with large computing power. This practical design enhances the reliability of data on the blockchain
generally, the transaction data in the blockchain ledger can not be "modified", it can only be "modified" through the new transactions that are approved. The process of correction will leave traces, which is why the blockchain can not be tampered with. Tampering refers to changing or misinterpreting by means of forgery
in today's common files and relational data, unless a special design is adopted, the system itself does not record modification traces. Blockchain ledger adopts a design different from that of files and databases. It draws on the design of ledger in reality, that is, to retain the traces of records. Therefore, we can not "modify" the account book without leaving traces, but can only "modify" the account book (see Figure 2)

Figure 6: bitcoin is centralized in the organization and logically centralized

when we imagine the future organization, the ideal prototype in our mind is often bitcoin organization: completely decentralized autonomous organization. But in practice, for the sake of efficiency and advancement, we will move closer to the centralized organization and finally find a suitable balance point

nowadays, in the blockchain projects that are created and issued through the smart contract of Ethereum and run in a community or ecological way, the ideal state of many projects is similar to the bitcoin organization, but the actual situation is between the completely decentralized organization and the traditional company

when we discuss the fourth feature of blockchain, which is decentralized self-organization, we are actually going out of the code world, involving human organization and collaboration. Now, various discussions and practical explorations have also revealed the significance of blockchain beyond technology: it may serve as an infrastructure to support human proction organization and collaborative change. This is another example of the complete isomorphism between blockchain and Internet. Internet is not only a technology, it has changed people's organization and collaboration

in general, Ethereum has brought blockchain into a new stage. When discussing Ethereum, if we want to summarize two key words, they are smart contract and token; If I can only say one, I will choose "Tong Zheng". I would rather look for its meaning from the history of the Internet and repeat the previous analogy: as a token of value, its role is similar to HTML. With HTML, what kind of website to build depends entirely on our imagination

8. 1. Blockchain is a distributed database (system) in a non secure environment
2. The blockchain uses cryptography to ensure that the existing data cannot be tampered with
3, the blockchain uses consensus algorithm to reach consensus on new data. The system with the above three properties is blockchain. Shengshi Huacai did a good job in this blockchain

9. These characteristics make the blockchain technology can be applied to many instries. The SMIC blockchain service platform launched by Changsha high tech Zone also solicits enterprises to go on the chain, which is a blockchain + public service mode.