As bitcoin matures , People have discovered the basic technology that supports bitcoin —— Blockchain technology has great potential in many application scenarios , To some extent, it may change the existing model . Some people mistakenly confuse blockchain with bitcoin , It's not . Blockchain （Blockchain） It is a distributed database system based on peer-to-peer network .
Blockchain is composed of a series of data blocks generated by cryptographic methods , Each block contains the hash value of the previous block （Hash）, From Genesis block （Genesis Block） Start connecting to the latest block , Forming a blockchain , Its structure is shown in the figure 1-6 Shown . Because the latter block needs to contain the information of the previous block , So the longer a blockchain stays , The more difficult it is to change .
Blockchain has decentralization 、 Limited transparency 、 Distributed reliable database 、 Autonomy 、 Records are hard to change 、 Quasi anonymity and so on , The explanation is as follows .
De centralization ： Blockchain data storage 、 transmission 、 The verification process is based on the distributed system structure , There is no centralized hardware or management organization in the whole system , The rights and obligations of any node are equal , The data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system .
Limited transparency ： The system is open , Except that the private information of the parties to the transaction is encrypted , The data of the blockchain is open to everyone , Anyone can query blockchain data and develop related applications through public interfaces .
Distributed reliable database ： The database of blockchain system adopts distributed storage , Any participating node can have a complete copy of the database , Each party can directly verify the records of the parties to the transaction .
Autonomy ： The blockchain adopts consensus based specifications and protocols （ Such as an open and transparent algorithm ） So that all nodes in the whole system can exchange data freely and safely in a de trusted environment , This makes it right “ people ” Trust in machines becomes trust in machines and algorithms , No human intervention .
Records are hard to change ： Once the information is validated and added to the blockchain , The account information will be updated accordingly , The record is hard to change , Because this information is related to all previous transactions （ That is the term “ chain ” The source of the ）. Various calculation algorithms and methods used in the system are used to ensure that the records in the database are permanent 、 In chronological order , And everyone else on the Internet can see it , Unless you can simultaneously control the system over 51％ The node of , Otherwise, changes to the database on a single node are invalid , The more nodes participating in the system , The more secure the database is . also , Blockchain data is also stored with a timestamp , This adds a time dimension to the data , With high traceability . therefore , The data stability and reliability of blockchain are extremely high .
Quasi anonymity ： The blockchain system uses the address linked to the user's public key as the identification , No need for traditional public key infrastructure （Public Key Infrastructure,PKI） Third party certification center （Certificate Authority,CA） Issue a digital certificate to confirm identity . By running consensus algorithm in the whole network node , Establish the consensus of honest nodes on the state of the whole network , Indirectly establishes trust between nodes . Users only need to publish addresses , There's no need to disclose your true identity , And the same user can constantly change the address . therefore , Transactions on the blockchain are not linked to the user's real identity , Only linked to the user's address , Quasi anonymity of transactions .