Introduction and classification of blockchain

1.

From the current mainstream blockchain projects, blockchain projects are mainly divided into four categories: the first category: currency; The second is platform; The third category: application category; The fourth type: asset token

currencies mainly act as the "exchange media" in the field of blockchain assets, and the exchange media refer to general equivalents, such as gold and silver bills in the past< (currency exchange on trading blockchain assets)

platform projects refer to the establishment of technical platforms to meet the needs of various blockchain application development, which can rece the threshold of application development on blockchain

application projects cover a wide range of fields, including finance, social networking, games, property rights protection, etc., and are also the fastest growing fields of blockchain assets

asset token project refers to the blockchain mapping of physical assets, that is, the physical assets on the chain. At present, there are no more than 10 varieties

01 currency

the first category is currency project, which is also the earliest blockchain project. Currency projects mainly include bitcoin and lightcoin. In addition, there is another kind of asset with the characteristics of anonymity. Its main functions include protecting the privacy of both sides of payment while realizing payment. The well-known ones are dash, monero and zcash. Currency is mainly used as the "exchange medium" in the field of blockchain assets. The exchange medium is the general equivalent you use to exchange goods. For example, gold, silver and silver bills can be used as the exchange medium in the past. At present, there are more than 2100 types of digital assets in the world, and the number of currency blockchain projects has increased rapidly recently. As of June 2018, bitcoin is still the largest market value

02 platform type

the second type is platform type blockchain project. The main function of platform type blockchain project is to establish a technical platform to meet the technical requirements of various blockchain application development; In short, platform applications allow developers to directly issue digital assets and write smart contracts on the blockchain. Smart contract is a computer program running on the blockchain database, which can be automatically executed under the conditions of its source code setting

for example, you develop a smart contract based on the house rent protocol on the blockchain. When the owner receives the rent, it will trigger the automatic execution and give the security key of the apartment to the tenant

the main function of platform blockchain projects is to establish the underlying technology platform, so that developers can do application development on the underlying technology platform. A considerable number of platforms are still in the development state. As of June 2018, Ethereum has the largest market value

03 application

the third category is application blockchain projects. Application projects are blockchain projects based on blockchain development platform (such as Ethereum), which can solve many problems in various fields of the real economy

for example, augur, Golem, vechain, omisego, which provides asset exchange and transfer services. Using blockchain technology, these projects can better solve the problems of trust and cross-border circulation. At the same time, using smart contracts and tokens on the blockchain, they can better realize automatic execution and greatly improve the efficiency of social and economic activities. Application blockchain projects cover a wide range of fields, including finance, social networking, games, property rights protection and so on. It is also the field with the fastest market value increment of blockchain projects at present

04 asset token

the fourth category is the asset token blockchain project. Asset token refers to linking the blockchain assets to physical assets such as gold and US dollars, which is the blockchain mapping of physical assets. As of February 2018, there are no more than 10 varieties. The typical representatives are usdt against US dollars, digix Dao against gold, Digix each token represents 1 gram of Gold Certified by the London Bullion Market Association. Asset token has the advantages of convenient transaction and safekeeping. First of all, asset token is more convenient for transaction. Because blockchain assets can be split, it has better liquidity

for example, at present, real estate needs to be transferred as a whole. If the real estate can be token, it can be split and purchased, which is more convenient for transaction. Secondly, the token of physical assets is more concive to custody. Gold is easy to wear out and cause losses in physical transactions, but there is no need for physical transfer after the token of physical assets, which is more concive to the custody of physical assets

2. Blockchain mainly solves the trust and security problems of transactions, so it proposes four technological innovations to solve this problem:
(1) distributed ledger, that is, transaction bookkeeping is completed by multiple nodes distributed in different places, and each node records complete accounts, so they can participate in monitoring the legitimacy of transactions, At the same time, they can testify together
different from traditional distributed storage, the uniqueness of distributed storage of blockchain is mainly reflected in two aspects: one is that each node of blockchain stores complete data according to block chain structure, while traditional distributed storage generally stores data in multiple copies according to certain rules. Second, the storage of each node in the blockchain is independent and has the same status, which relies on the consensus mechanism to ensure the consistency of storage, while the traditional distributed storage generally synchronizes data from the central node to other backup nodes[ 8]
no single node can record the account data separately, so as to avoid the possibility that a single bookkeeper is controlled or bribed to record false accounts. In theory, unless all the nodes are destroyed, the accounts will not be lost, so as to ensure the security of the account data
(2) asymmetric encryption and authorization technology, the transaction information stored on the blockchain is public, but the account identity information is highly encrypted, which can only be accessed under the authorization of the data owner, thus ensuring the data security and personal privacy
(3) consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and achieve a balance between efficiency and security
the consensus mechanism of blockchain has the characteristics of "the minority is subordinate to the majority" and "everyone is equal", in which "the minority is subordinate to the majority" does not completely refer to the number of nodes, but also can be the computing power, the number of shares or other characteristics that can be compared by computers“ "Everyone is equal" means that when the nodes meet the conditions, all nodes have the right to put forward the consensus results first, and then directly recognized by other nodes, and finally may become the final consensus results. Taking bitcoin as an example, the workload proof is adopted. Only when more than 51% of the accounting nodes in the whole network are controlled can a nonexistent record be forged. When there are enough nodes in the blockchain, this is basically impossible, thus eliminating the possibility of fraud.
(4) smart contract, which is based on these trusted and tamperable data, can automatically execute some pre-defined rules and terms. Take insurance as an example. If everyone's information (including medical information and risk occurrence information) is true and reliable, it is easy to carry out automatic claim settlement in some standardized insurance procts

3. 1. Public chain, no official organization and management organization, no central server, participating nodes freely access to the network according to the system rules, not controlled, and work based on consensus mechanism among nodes Subversive: absolutely credible and open) < br > typical case: digital currency represents bitcoin < br > 2. The private chain is built within a group. The operation rules of the system are set according to the requirements of the group, and the modification or read permissions are limited to some extent, while maintaining the authenticity and partial decentralization of the blockchain Typical case: R3 < br > 3. Alliance chain, jointly initiated by several institutions, is between the public chain and the private chain, and has the characteristics of partial decentralization. The read permission on the fast chain in this area may be public or partially public, that is to say, multiple pre selected nodes are designated as bookkeepers internally, and the pre selected nodes compete for bookkeeping permission, Other access nodes can participate in the transaction, but not the accounting process The abilities of the candidates should not be uneven< Br > (relatively credible and open) < br > existing cases: Super ledger < br > example:? In the case of loan diversion, when the user jumps to the other party's website for registration through our link, the docking party can choose to cheat and say that it has not received the user's registration request. However, if we put the user registration behavior into the block, if the docking party wants to receive the user registration behavior, it must pay us at the same time.

4. The classification of Chongqing jinwowo analysis blockchain technology is as follows: according to the participation access mechanism of blockchain, that is, the blockchain account book is not public, we can divide the blockchain into three categories: public chain, private chain and alliance chain.

5. What are the characteristics of public chain, private chain and alliance chain
according to the access mechanism, blockchain can be divided into three categories: public chain, private chain and alliance chain. Other types of blockchains may be born in the future
the public chain is open and transparent. Any indivial or group in the world can send transactions on the public chain, and the transactions can be effectively confirmed by the blockchain. Everyone can compete for bookkeeping rights. Bitcoin blockchain is a typical representative of public chain
the alliance chain is semi open. It is a blockchain used within a group or organization. Several nodes need to be designated as bookkeepers in advance. The generation of each block is decided by all preselected bookkeepers. Other nodes can trade, but they have no bookkeeping rights
the private chain is completely closed. Only the blockchain technology is used for bookkeeping, and the bookkeeping right is not open, and only internal transactions are recorded, which are exclusively enjoyed by companies or indivials.

6. A new resolution initiated by representative Adam kinzinger, a Republican from Indiana, has been submitted to the US House of Representatives, calling on the government to formulate national policies on emerging technologies, including digital currency and blockchain technology
the resolution calls on the idea of bitcoin, but does not directly mention its name. Instead, it calls it "alternative illegal currency". Blockchain technology is the key point, which points out that this technology has the potential to "fundamentally change" the way trust and security are built on online transactions
but in fact, the United States has not taken action to formulate this rule. However, there is a global blockchain alliance R3 in the process of formulating the standard for the use of blockchain. Of course, blockchain is just a technology that can be used by any enterprise. In China, there is a project called decent, which is more avant-garde. It uses blockchain technology to build a decentralized content publishing platform, but it may encounter some problems in China.