Block Chain-4: The basic type of block chain and intelligent contract _ block chain

One, the public chain

The public chain means anyone in the world can read, anyone can send a transaction and the transaction can be effectively confirmed, any
People can participate in the consensus process of the block chain

There are several features:

Protect users from the influence of developers
In the public chain, program developers have no right to interfere with users, and block chains can protect their users.

Low access threshold
Anyone can access it, as long as there is a computer that can be networked to meet basic access conditions.

All data is exposed by default

Each participant in the public chain can see all the transactions in the entire distributed ledger. Second, private chain

A private chain is a chain of blocks whose write permission is in the hands of only one organization, with the purpose of restricting the read or opening permissions.

The private chain has the following characteristics: The transaction speed is very fast
A small number of nodes in the private chain have a high degree of trust and do not require each node to validate a transaction. Therefore, the private chain transactions faster than the public chain. Provide better protection for privacy
Private chain data is not made public and cannot be obtained by anyone with a network connection. The transaction costs have been drastically reduced or even zero.
A private chain can be completely free or at least a very inexpensive transaction. If a physical institution controls and processes all transactions, it will no longer be required to charge for work. Helps protect their basic products from being destroyed
The use of private chains by banks and traditional financial institutions ensures that they have a vested interest and that the original ecosystem is not destroyed. Third, the Alliance chain

The Alliance chain refers to a block chain whose consensus process is controlled by a preselected node. For example, for a community of 15 financial institutions, each agency runs a node, and in order for each block to enter into force, it needs to be confirmed by more than half of the 8 institutions. The alliance chain can be regarded as "partial to central". Smart Contracts

It's a computer program, a central system that anyone can use, and it doesn't require any intermediary agency.

It has several conditions: money must be involved. No money all trades are empty talk, whether using fiat money, or using encrypted digital currency, in short, must have currency. Assets must be digitized. How to digitize a car. The answer is to give it a cipher to learn the lock. The cars we use now are all physical locks, so the delivery car is actually delivering the car keys. Imagine that one day the lock of a car becomes a cryptographic public key, and only the person holding the private key can open the car. It's sci-fi, isn't it. But this can be achieved. Assets must be networked and have absolute trust in a database.

The Intelligent contract uses the program algorithm to replace the execution contract, which eliminates the moral hazard of executing subject and transaction.