Representative of Shanxi blockchain

1.

blockchain includes public blockchain, joint (instry) blockchain and private blockchain. Public chain point-to-point e-cash system: bitcoin, smart contract and decentralized application platform: Ethereum

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. In essence, it is a decentralized 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 a batch of bitcoin network transaction information, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

extended data

according to the different degree of blockchain network centralization, three kinds of blockchains under different application scenarios are differentiated:

1. The blockchain with the whole network open and without user authorization mechanism is called public chain

2. The authorized nodes are allowed to join the network, and the information can be viewed according to the authority. It is often used in the inter agency blockchain, which is called alliance chain or instry chain

3. All the nodes in the network are in the hands of one organization, which is called private chain

alliance chain and private chain are also called licensing chain, and public chain is called non licensing chain

blockchain features

1, 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. Decentralization is the most prominent and essential feature of blockchain

2. Openness. Blockchain technology is based on 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

3. 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

4. Safety. As long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily manipulated 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 can be transferred anonymously

2. In the past two years, blockchain alliances have sprung up. What are their representatives
in the early stage of the development of the blockchain instry, many enterprises and institutions formed a blockchain alliance to share the research results of blockchain technology and seek wider application of blockchain technology
in the past two years, blockchain alliances have emerged. As of July 2017, there are R3 composed of more than 40 international banks, hyperledger initiated by Linux foundation, Zhongguancun blockchain Instry Alliance located in the core hinterland of China's Internet, China ledger alliance jointly initiated by 11 institutions, gold chain alliance jointly established by 25 financial institutions, and so on Russia's blockchain alliance, known as "Russian version R3", seeks to combine with micro finance, Qianhai international blockchain ecosphere alliance led by Shenzhen Qianhai administration, and Lujiazui blockchain Financial Development Alliance in Lujiazui
many organizations and talents join to promote the vigorous development of blockchain.

3. 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

4. 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.

5. Bitcoin market suddenly soared, and now you can buy it. But you have to buy by yourself. Think about it, because bitcoin is a virtual currency. Market uncertainty, buy carefully.