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㈠What does blockchain mean and what are its main uses

In recent years, a hot word has appeared frequently on the Internet, and that is "blockchain". It gives people a very noble and powerful feeling, but many people don’t know what blockchain means? And what are the main uses of blockchain? Let’s take a look at the relevant content that has been issued.

Blockchain Blockchain is actually equivalent to a disintermediated database, which is composed of a series of data blocks. Each of its data blocks contains information about a Bitcoin network transaction, which is used to verify the validity of its information and generate the next block. In other words, blockchain is essentially a decentralized database.

In a narrow sense, blockchain is a chain data structure that combines data blocks in a sequential manner in chronological order, and uses cryptography to Guaranteed immutable and unforgeable distributed ledger. Broadly speaking, blockchain is actually a distributed infrastructure and computing method that is used to ensure the security of data transmission and access.

In addition, the blockchain is composed of six infrastructures: data layer, network layer, consensus layer, incentive layer, contract layer and application layer. Regarding its role, blockchain is mainly used to solve the trust and security issues of transactions. The above is the relevant content about the meaning and function of blockchain. I hope it can help friends in need.

㈡ Explanation of the term blockchain

Blockchain is a series of verified blocks, each of which is connected to the previous block, all the way to the creation world block.

1. Blockchain (BlockChain)

Blockchain is a series of verified blocks, each of which is connected to the previous block. to the genesis block. Blockchain is the underlying technology of digital currencies such as Bitcoin. It is a decentralized distributed shared ledger. Blockchain, artificial intelligence, and big data are known as the three major directions of financial technology. Ma Chajue

In 2009, he built an open source project for the Bitcoin system and officially announced the birth of Bitcoin. But when Bitcoin gradually became popular, Satoshi Nakamoto quietly left and disappeared from the Internet.

㈢ Blockchain Encyclopedia: The Past and Present of Blockchain - 3.0 Era

The representative of the blockchain 1.0 era is Bitcoin, the representative of the 2.0 era is Ethereum, and The chaotic era of various copycats and air coins. Blockchain 3.0 is the era of consumer-level blockchain that has truly entered commercial and physical applications after the troubled times. The typical symbol is the emergence of tokens. The pass has brought about changes in traditional business models and production relations. The pass has moved from the digital world to the real economy and has begun to seek practical applications in various industries.

The pass has three requirements:Elements are indispensable.

Pass: The pass can be circulated on a large scale in a network and can be verified anytime and anywhere; Certificate: As a proof of digital rights and interests, the pass must be a certificate of rights and interests that exists in digital form, and it must represent It is a right, an inherent and intrinsic value; value: the token must have economic value.

In this way, the meaning of "token economy" is not difficult to understand. The token economy is a large-scale group collaboration based on tokens. It maximizes the role of tokens, allows every role that creates value to share value fairly, fully mobilizes participation motivation, and forms a self-organizing form.

Major changes in the blockchain 3.0 era

The token economy has laid the theoretical basis and technical support for the large-scale application of blockchain, and the future world will also be transformed by it. Large-scale changes include:

1. Fragmented investment, fragmented income, subverting the traditional way of doing business on the Internet. In the traditional Internet era, it was impossible for ordinary people to participate in the investment of a company, but the emergence of blockchain allows ordinary people to make fragmented investments in a large asset. Assuming that Alibaba originally adopted blockchain for fragmented investment, then all fragmented shareholders who invested in Alibaba would be able to reap a return on investment that has increased thousands of times today!

2. Break the money-burning model of the Internet and make everyone a winner. The free model of the traditional Internet is essentially to obtain a large number of users through free products to form monopolies and barriers, and then make profits through advertising and value-added services on this basis. In the blockchain 3.0 era, project income is redistributed by issuing tokens to attract more early investors and community users. As the number of users holding tokens increases, the value of the tokens will become higher and higher, and community users, investors, and projects can all benefit from it. In this way, the money-burning model of providing free services in the early days of the traditional Internet can also be improved, and everyone will become a winner.

3. Breaking down the traditional corporate organizational hierarchy, self-organization may become a future trend. In the blockchain 3.0 era, through the establishment of distribution and collaboration mechanisms through smart contracts, it can be more efficient and accurate than enterprises. All token owners will naturally form a community. Everyone has the same goal - "to promote the development of the project and make it a success". They are all members of the community, contribute to the community, promote the value-added of the token, and thus gain benefits together. profit. From a philosophical perspective, this new self-organizing community of freedom, independence, and equality must be the future trend. Gojoy blockchain e-commerce is a blockchain self-organized community. Every consumer is a token owner and a fragmented investor, so he is very happy to co-create and build Gojoy value.

Therefore, we can look forward to the blockchain 3.0 token economyIn the era of great development, everything that exists today may be subverted. What we need to be prepared for is to work hard to embrace the blockchain. If you want to seize the trend of blockchain and understand how to transform into blockchain, please leave a message to communicate and we will take you to learn the blockchain professional certification course.

㈣ An easy-to-understand explanation of blockchain

The popular explanation of blockchain technology is as follows:

To put it simply: blockchain is the use of a package of existing A new generation of network system formed using advanced network technology. This network system has a new structure, a new mechanism, and unprecedented new value. Five major technologies or innovations are specifically used: encryption technology, P2P network technology, distributed storage technology, consensus mechanism, and smart contracts.

Essentially: it is a shared database, and the data or information stored in it is "unforgeable", "full-process traces", "traceable", "open and transparent" and "collectively maintained" ” and other characteristics. Based on these characteristics, blockchain technology has laid a solid foundation for "trust-based sales" and created a reliable "cooperation" mechanism. Yunchun has broad application prospects.

2. Openness.

In addition to the encryption of private information of all parties to the transaction, the blockchain data is open to everyone and provides a flexible script code system. The entire system information is highly transparent and within the rules specified by the system. Nodes cannot deceive each other.

3. Autonomy.

Consensus technology, smart contracts.

㈤ Four consensus mechanisms of blockchain

The consensus mechanism of blockchain can be divided into the following four categories: Proof of Stake mechanism, Proof of Work mechanism, Pool verification and pool shares Authorization certification mechanism.
Blockchain is a chain composed of blocks one after another. Each block stores a certain amount of information, and they are connected into a chain in the order in which they were generated. This chain is saved in all servers. As long as one server in the entire system can work, the entire blockchain is safe. These servers are called nodes in the blockchain system, and they provide storage space and computing power support for the entire blockchain system.

㈥ Several major blockchain consensus mechanisms and their advantages and disadvantages

First of all, no consensus mechanism is perfect. Each consensus mechanism has its advantages and disadvantages. Some consensus mechanisms are Designed to solve specific problems.
1.pow (Proof of Work) Proof of Work
One sentence introduction: The more you work, the more you receive.
Relying on machines to perform mathematical operations to obtain accounting rights, the resource consumption is higher than other consensus mechanisms and the supervision is weak. At the same time, each time a consensus is reached, the entire network needs to participate in the operation. The performance efficiency is relatively low, and fault tolerance is not allowed. 50% of the nodes in the entire network are faulty.
Advantages:
1) The algorithm is simple and easy to implement;
2) Nodes can reach consensus without exchanging additional information;
3) Destroying the system requires extreme investmentBig cost;
Disadvantages:
1) Waste of energy;
2) Block confirmation time is difficult to shorten;
3) The new blockchain must find a different Hash algorithm, otherwise you will face Bitcoin’s computing power attack;
4) It is easy to produce forks and need to wait for multiple confirmations;
5) There is never finality, and a checkpoint mechanism is needed to make up for the finality. Sex;
2.POS Proof of Stake, Proof of Stake
One sentence introduction: The more you hold, the more you get.
The main idea is that the difficulty of obtaining node accounting rights is inversely proportional to the equity held by the node. Compared with PoW, the resource consumption caused by mathematical operations is reduced to a certain extent, and the performance has been improved accordingly, but it is still The method of obtaining accounting rights based on hash operation competition has weak supervision. The fault tolerance of this consensus mechanism is the same as PoW. It is an upgraded consensus mechanism of Pow. According to the proportion of tokens and time occupied by each node, the mining difficulty is reduced in an equal proportion, thereby speeding up the speed of finding random numbers
Advantages: shortened to a certain extent The time it takes to reach consensus; there is no longer a need to consume a lot of energy for mining.
Disadvantages: Mining is still required, which essentially does not solve the pain points of commercial applications; all confirmations are only probabilistic expressions, not deterministic things. In theory, there may be other attacks. For example, the DAO attack on Ethereum caused a hard fork of Ethereum, and the emergence of ETC as a result of the incident actually proved the failure of the hard fork.
The principle of DPOS is the same as that of POS, except that some "people's congress representatives" are selected.
The BitShares community first proposed the DPoS mechanism.
The main difference from PoS is that nodes elect several agents, who verify and keep accounts. Its compliance supervision, performance, resource consumption and fault tolerance are similar to PoS. Similar to board voting, currency holders vote for a certain number of nodes to perform verification and accounting on their behalf.
The working principle of DPoS is:
Decentralization means that each shareholder has influence according to the proportion of his shareholding, and the result of the vote of 51% shareholders will be irreversible and binding. The challenge is to achieve 51% approval in a timely and efficient manner. To achieve this goal, each shareholder may grant his or her voting rights to a representative. The top 100 representatives with the most votes take turns to generate blocks according to a set schedule. Each representative is assigned a time slot to produce blocks. All representatives will receive compensation equal to 10% of the transaction fees included in an average block. If an average block contains 100 shares as a transaction fee, a representative will receive 1 share as compensation.
Network delays may prevent some representatives from broadcasting their blocks in time, which will cause the blockchain to fork. However, this is unlikely to happen because representatives of the manufacturing block can have direct connections with representatives of the pre- and post-manufacturing blocks. After establishing this with youA direct connection to the representative (and perhaps the representative after him) is to ensure that you get paid.
This mode can generate a new block every 30 seconds, and the possibility of a blockchain fork under normal network conditions is extremely small, and even if it occurs, it can be resolved within a few minutes.
Become a representative:
To become a representative, you must register your public key on the network and then be assigned a 32-bit unique identifier. This identifier is then referenced in the "header" of each transaction data.
Authorization votes:
Each wallet has a parameter setting window in which the user can select one or more representatives and rank them. Once set up, every transaction a user makes will move votes from "Input Representatives" to "Output Representatives". Generally, users will not create transactions specifically for the purpose of voting because that will cost them a transaction fee. But in an emergency, some users may find it worthwhile to pay a fee to change their vote in a more positive way.
Keep representatives honest:
Each wallet will display a status indicator to let users know how their representatives are performing. If they miss too many blocks, the system will recommend the user to switch to a new representative. If any representative is found to have signed an invalid block, all standard wallets will require the election of a new representative before each wallet can conduct further transactions.
Resisting attacks:
In terms of resisting attacks, because the power rights obtained by the top 100 representatives are the same, each representative has an equal voting right. Therefore, power cannot be concentrated in a single representative by gaining more than 1% of the vote. Since there are only 100 representatives, it is conceivable that an attacker could perform a denial of service attack on each representative whose turn it is to produce a block in turn. Fortunately, the threat of this particular attack is easily mitigated due to the fact that each representative is identified by his public key rather than his IP address. This will make it more difficult to identify the target of a DDOS attack. The potential direct connection between representatives will make it more difficult to prevent them from producing blocks.
Advantages: Significantly reduces the number of nodes participating in verification and accounting, and can achieve second-level consensus verification.
Disadvantages: The entire consensus mechanism still relies on tokens, and many commercial applications do not require the existence of tokens.
3.PBFT: Practical Byzantine Fault Tolerance, Practical Byzantine Fault Tolerance
Introduction: It provides (n-1)/3 fault tolerance on the premise of ensuring liveness & safety.
In distributed computing, different computers try to reach a consensus through message exchange; but sometimes, the coordination computer (Coordinator/Commander) or member computer (Member/Lieutanent) on the system may be affected by the system.Errors and incorrect messages are exchanged, affecting the final system consistency.
The Byzantine Generals Problem looks for possible solutions based on the number of faulty computers. This cannot find an absolute answer, but it can only be used to verify the effectiveness of a mechanism.
The possible solution to the Byzantine problem is:
Consistency is possible in the case of N ≥ 3F + 1. Among them, N is the total number of computers, and F is the total number of problematic computers. After information is exchanged between computers, each computer lists all the information obtained and uses the majority of the results as a solution.
1) System operation can be separated from the existence of coins. Each node of the pbft algorithm consensus is composed of business participants or supervisors, and security and stability are guaranteed by business stakeholders.
2) The consensus delay is about 2 to 5 seconds, which basically meets the requirements of commercial real-time processing.
3) The consensus efficiency is high and can meet the needs of high-frequency transaction volume.
Disadvantages:
1) When 1/3 or more of the bookkeepers stop working, the system will not be able to provide services;
2) When 1/3 or more of the bookkeepers jointly commit evil , and when all other bookkeepers are divided into two network islands, malicious bookkeepers can cause the system to fork, but will leave cryptographic evidence
Let’s talk about two domestic ones~
4.dBFT: delegated BFT Authorized Byzantine Fault Tolerance Algorithm
Introduction: The dBFT mechanism adopted by Xiaoyi selects bookkeepers based on equity, and then the bookkeepers reach a consensus through the Byzantine Fault Tolerance algorithm.
This algorithm has made the following improvements based on PBFT:
Improved the request response mode of the C/S architecture into a peer-to-peer node mode suitable for P2P networks;
Modified the static consensus participating nodes Improved to a dynamic consensus participating node that can dynamically enter and exit;
A voting mechanism based on the proportion of equity held is designed for the generation of consensus participating nodes, and consensus participating nodes (accounting nodes) are determined through voting;
/>Introducing digital certificates into the blockchain solves the problem of authenticating the true identity of accounting nodes in voting.
Advantages:
1) Professional bookkeeper;
2) Can tolerate any type of errors;
3) Bookkeeping is completed by multiple people, each block All are final and will not fork;
4) The reliability of the algorithm has strict mathematical proof;
Disadvantages:
1) When 1/3 or more bookkeepers stop working Afterwards, the system will be unable to provide services;
2) When 1/3 or more of the bookkeepers jointly commit evil, and all other bookkeepers are divided into two network islands, the malicious bookkeeper can use The system will fork, but cryptographic evidence will be left behind;
In summary, the core point of the dBFT mechanism is to ensure thatThe finality of the system makes the blockchain suitable for real financial application scenarios.
5.POOL verification pool
Based on traditional distributed consistency technology, plus data verification mechanism.
Advantages: It can work without tokens. Based on mature distributed consensus algorithms (Pasox, Raft), it can achieve second-level consensus verification.
Disadvantages: The degree of decentralization is not as good as bictoin; it is more suitable for a multi-center business model with multi-party participation.

㈦ What does blockchain mean?

Blockchain is a new application model of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. The so-called consensus mechanism is a mathematical algorithm that establishes trust and obtains rights and interests between different nodes in the blockchain system.

1. In a narrow sense, blockchain is a chain data structure that combines data blocks in a sequential manner in chronological order, and is cryptographically guaranteed to be non-tamperable. and an unforgeable distributed ledger.

2. Broadly speaking, blockchain technology uses block chain data structures to verify and store data, uses distributed node consensus algorithms to generate and update data, and uses cryptography to ensure data transmission. and access security, a new distributed infrastructure and computing method that uses smart contracts composed of automated script codes to program and operate data.

(7) Extended reading on blockchain:

1. In 2008, Satoshi Nakamoto proposed the concept of blockchain for the first time. In the years that followed, it became a core component of the electronic currency Bitcoin: serving as a public ledger for all transactions.

2. By 2014, "Blockchain 2.0" became a term about a decentralized blockchain database. For this second-generation programmable blockchain, economists believe that its achievement is that “it is a programming language that allows users to write more sophisticated and intelligent protocols. Therefore, when profits reach a certain level, You can earn income from completed shipping orders or dividends from shared certificates."

3. In 2016, the Central Securities Exchange of the Russian Federation (NSD) announced a pilot project based on blockchain technology. Many institutions with regulatory powers in the music industry are beginning to use blockchain technology to establish test models for collecting royalties and managing copyrights worldwide.

4. The timestamp service and existence proof of the blockchain, the time when the first blockchain was generated and the events that were happening at that time are permanently retained.

5. The Bitcoin company BTCC launched a service "Millennium Chain" in 2015, which is the blockchain engraving service, which uses the above principles. Users can engrave text on the blockchain through this service and save it permanently.

What does blockchain mean?

Blockchain, an important concept of Bitcoin, is essentially aThe centralized database, which is also the underlying technology of Bitcoin, is a series of data blocks generated using cryptographic methods. Each data block contains a batch of information about Bitcoin network transactions. Used to verify the validity of its information (anti-counterfeiting) and generate the next block.

Blockchain is a new application model of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm.

2. In order to realize the great leap forward development of blockchain finance, in order to promote the new development of China’s economy, accelerate the circulation of global assets, and realize the renaissance that generations have been striving for. dream.

Puyin Group held the Puyin Blockchain Finance Guiyang Strategy Release Ceremony in Guizhou on December 9, 2016. At the meeting, the blockchain will realize the digital circulation of assets and the blockchain financial transaction model. , and discuss the application of blockchain services and social public industries.