What are the public, private and consortium of blockchain?

The blockchain, according to its access mechanism, can be divided into three basic types, namely: public blockchain, consortium blockchain, and private blockchain.

·Public blockchain

The public blockchain is the earliest blockchain, which, as the name implies, is public and open. The public blockchain is the most open and decentralized blockchain, where data update, storage and operation do not rely on a centralized server, but on every node in the network.

In the public blockchain, every participant has the right to access the distributed ledger, every record is not subject to supervision by any organization, program development organizations and developers have no right to interfere with users, and the blockchain can protect its users.

Relying relies on encryption technology to ensure its security, public blockchain is generally applicable to B2C, C2C, or C2B application scenarios such as cryptocurrency, bulk-oriented e-commerce, and Internet finance. The typical public blockchain is Bitcoin.

·Consortium blockchain

Consortium blockchain refers to the blockchain whose consensus process is under the control of preselected nodes, and multiple preselected nodes are designated to act as the bookkeepers in a group, the generation of each block is co-determined by all preselected nodes (which participate in the consensus process), and other access nodes can participate in transactions without inquiring the bookkeeping process (in essence, it is host bookkeeping, simply in the variant form of distributed ledger), and anyone else can make qualified queries through the blockchain's open API.

Consortium blockchain can only be participated in by alliance members, and the reading and writing authority and bookkeeping participation authority on the blockchain are determined according to the rules of the alliance. The consortium blockchain network is jointly maintained by the member organizations, and the network access is generally through the gateway nodes of the member organizations. The consortium blockchain platform should enable member management, authentication, authorization, monitoring, audit and other security management functions.

Consortium blockchain is a blockchain that requires registration permission, whose consensus process is controlled by pre-selected nodes. Generally, it is applicable to B2B scenarios such as inter-organizational trading, settlement, or clearing. For example, in the inter-bank payment, settlement and clearing system, the gateway nodes of the banks can be used as the bookkeeping nodes in the form of consortium blockchain.

·Private blockchain

Private blockchain is not open to the public, in which only authorized nodes can participate and view the blockchain type of data. The typical application of private blockchain is the blockchain developed by PBOC for issuing PBOC's digital currencies. Different from the complete decentralization of public blockchain, private blockchain is a blockchain with certain centralized control.

The fewer nodes on a blockchain, the easier it is for bad actors to collude, therefore, private blockchain administrators must ensure that nodes are added to the blocks and they're verified as highly trusted.