mind Mapping:
Background:
Almost all transactions on the Internet require the help of trusted third-party credit institutions to process electronic payment information. Such systems are inherently subject to a "credit-based model".
Blockchain technology is the basic technology for building the Bitcoin blockchain network and encrypting the transmission of transaction information. Among them, the characteristics based on the principle of cryptography enable any two parties who reach an agreement to pay directly, thus eliminating the need for the participation of third-party institutions.
What is blockchain?
Blockchain technology itself is still developing, and there is still a lack of unified norms and standards. Wikipedia gives the definition as:
A blockchain —originally, block chain —is a distributed database that maintains a continuously-growing list of data records hardened against tampering and revision.
It consists of data structure blocks—which hold exclusively data in initial blockchain implementations, and both data and programs in some of the more recent implementations—with each block holding batches of individual transactions and the results of any blockchain executables. Each block contains a timestamp and information linking it to a previous block.
The definition given by Wikipedia puts it simply: A blockchain (original blockchain) is a distributed database that maintains an ever-growing list of data records, enhancing algorithmic tampering and modification.
What is blockchain? Simply put, it is a special distributed database that belongs to a decentralized recording technology.
How traditional databases manage data,
1. Data is only stored in a specific database; (single database)
2. Add operations such as deleting and modifying the database. This operation is opaque and theoretically can not be disclosed to anyone;
3. The database administrator has the highest full management authority over the database. Can view, modify and delete data; (single administrator management mode)
Such a database has the following characteristics (not defined as disadvantages here, since these characteristics may also have positive aspects from different perspectives):
1. If this particular database is corrupted, the data is lost (low availability)
2. The database operation record is opaque to the user (the user is unaware of what the database administrator has done, and cannot be traced back)
3. Whether the data has been tampered with, and whether the newly added data is authentic or not is unknown (the reliability of the data is unknown)
Compared with traditional bookkeeping technology, or traditional data recording technology, blockchain features include:
1. Decentralized and trustless, consensus can be reached without centralized control
The blockchain consists of many nodes to form an end-to-end network, and there is no centralized equipment and management organization. Data exchange between nodes is verified by digital signature technology, without mutual trust, as long as it is carried out in accordance with the established rules of the system, nodes cannot and cannot deceive other nodes
2. Immutable and traceable: maintain a growing chain (large ledger), only records can be added, and records that have occurred cannot be tampered with. This is almost impossible to happen unless more than 51% of the nodes in the entire network can be controlled to modify at the same time. Each transaction in the blockchain is concatenated with two adjacent blocks through cryptographic methods, so the history of any transaction can be traced;
3. Open, consensus, anyone can participate in the blockchain network, each device can be used as a node to obtain a complete copy of the database, but there is no single user who can control it, in the blockchain Based on a consensus mechanism, the nodes in the system jointly maintain the entire blockchain through competitive computing. If any node fails, the remaining nodes can still work normally.
4. The identity is unique and cannot be forged. The identity (digital signature) of each node (member user) is unique and unforgeable, and can be used as an identification sign;
5. The transaction is transparent and the two parties are anonymous. The operating rules of the blockchain are open and transparent, and all data information is also open, so every transaction is visible to all nodes. Since nodes are trustless, there is no need to disclose identities between nodes.
What problem does blockchain solve:
Compared with the current data recording method, two problems have been greatly improved:
1. The most important thing is to solve the problem of intermediary credit. In the past, it was difficult to achieve collaboration between two people who did not know and trust each other, and had to rely on a trusted third party. Blockchain technology can realize the transfer (transaction record) behavior of mutual trust between the two parties without the participation of any intermediary agency.
2. Secondly, the recorded information is true and transparent, avoiding the possibility of data being tampered with
Types of blockchain
According to different application scenarios and design systems, it is generally divided into public chain, private chain and alliance chain.
Public blockchain:
Nodes in the network can be accessed arbitrarily, data read and write permissions in the network are not restricted, and anyone can participate in the consensus process. For example, Bitcoin is a typical public chain;
Private blockchain:
The nodes in the network are controlled by an organization, the write permission is limited to one organization, and the read permission is limited and open to the outside world, such as R3 CEV, a blockchain alliance formed by 42 banks around the world;
Private blockchain is actually a very confusing term. Such a system is nothing more than a shared database in the traditional sense, and does not have the decentralization characteristics of traditional blockchains;
Consortium blockchain:
The node part of the network can intervene arbitrarily, and the other part must be authorized to intervene, such as liquidation;
Comparison of three blockchain features:
Method to realize:
The so-called blockchain technology is not a single technology, but the result of the integration of multiple technologies, which are combined in a new structure to form a new way of data recording, storage and expression.
The technologies that realize the blockchain mainly include: distributed data storage, consensus mechanism, point-to-point transmission, encryption algorithm
The specific technical implementation method will be written and analyzed separately in the future.
Disadvantages of blockchain technology:
As a technology, the design of blockchain can be called very delicate, but the practical application is not as simple as picking it up.
The following three deficiencies are obvious:
1. Decentralization is difficult
Relying on millions of nodes around the world (in fact, Bitcoin wallets, each of which is synchronized with a blockchain file), as well as Bitcoin mining machines that perform encryption operations day and night, the maintenance of Bitcoin The safe operation of the coin blockchain. Therefore, we can think that the difficulty of achieving "decentralization" is very high.
Bitcoin is still like this, so what about the altcoins, forked coins, and ICO coins that are now mixed with fish and shrimps? Do they have the ability to build such a solid blockchain system? Just create a white paper and start throwing coins everywhere in the last exchange. Can your number of nodes support "decentralization"? Is it possible to prevent 51% attacks? It can be said with certainty that the vast majority of these "air coins" are fishing in troubled waters and are pseudo "decentralization".
2. Performance
problems (block capacity problem):
Everyone has a complete ledger, and sometimes it is necessary to trace every record. Therefore, as time progresses, when the transaction data is too large, there will be performance problems. For example, the first use needs to download all the transaction records in the history to work properly. , each transaction to verify that you do have enough money, you need to go back through each transaction to calculate the balance. While performance issues can be mitigated with some technical means (such as indexing), the problem is clearly there.
3. Data logging is slow to complete
Blockchain transactions are delayed. Taking Bitcoin as an example, the validity of the currently generated transaction is affected by network transmission, because most nodes on the network need to know the transaction until the next billing cycle. (Bitcoin is controlled at about 10 minutes), that is, the transaction must be recognized by most nodes. It is also affected by a small probability event, that is, when there are two or more nodes competing for the accounting power on the network at the same time, then two or more blockchain branches will be generated in the network. At this time, the data recorded by that branch will be If it is valid, it will have to wait for the next billing cycle, which is finally determined by the longest blockchain branch. Therefore, the transaction data of the blockchain is delayed.
blockchain application
Many views will compare the TCP/IP protocol and blockchain technology to describe the changes it will bring in the future. It will be as great as the development of the TCP/IP protocol has an impact on people's lives. We cannot confirm the size of this impact now, but users' perception of this technology may not be as obvious as the rise of the Internet back then.
According to several core characteristics of the blockchain: decentralization, distributed records, point-to-point transmission, and cannot be tampered with. Any application that requires the above aspects can become the application scenario of the blockchain
Predictable application trends are:
1. In the credit record system, identity authentication system or asset authentication system, many questions that prove "is this house my property" and "I am me" will disappear;
2. Operational costs such as transfers and transactions between banking institutions and between individuals are greatly reduced, and the procedures are simplified
3. Smart contracts
4. Logistic receipt
5.……
personal opinion:
It is a well-known fact that the use of blockchain is very broad, but many views claim that blockchain has the potential to subvert many industries. I agree with the view with reservations.
First of all, blockchain is just a "basic" technology. It has the potential to create new foundations for economic and social systems, but it is not "subversive". Except for the technical problems that have not been solved by itself, it cannot be used enough in a short period of time. Low-cost solutions allow users to abandon traditional business models and quickly overwhelm incumbents.
Secondly, the real use of blockchain requires the integration of resources and information from multiple fields, that is, multiple fields accept the use of blockchain as a data recording method, and the realization of this also takes a relatively long period of time.
In addition, with the introduction of new Internet technologies, for the original industry, both traditional industry practitioners and users are more willing to see the integration and addition of technology and systems, thereby improving the efficiency and security of the system and improving the original The inadequacy is not subversion.
Blockchain is a technology, not a product. At the same time, compared with other popular technologies, such as AR\VR\AI, the applications involved in blockchain are all of higher importance, such as payment, asset certification, etc. Any technical problem may lead to huge losses. Therefore, until the blockchain technology and pattern are mature and stable, it is difficult to generate large-scale income and profits. You can't use blockchain for the sake of blockchain, but to find a new business ecological environment and give full play to its advantages.