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What are the cancelled blockchains
Publish: 2021-04-23 03:49:51
1.
blockchain includes public blockchain, joint (instry) blockchain and private blockchain. Public chain point-to-point e-cash system: bitcoin, smart contract and decentralized application platform: Ethereum
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies
blockchain is an important concept of bitcoin. In essence, it is a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of bitcoin network transaction information, Used to verify the validity of its information (anti-counterfeiting) and generate the next block
extended data
according to the different degree of blockchain network centralization, three kinds of blockchains under different application scenarios are differentiated:
1. The blockchain with the whole network open and without user authorization mechanism is called public chain
2. The authorized nodes are allowed to join the network, and the information can be viewed according to the authority. It is often used in the inter agency blockchain, which is called alliance chain or instry chain
3. All the nodes in the network are in the hands of one organization, which is called private chain
alliance chain and private chain are also called licensing chain, and public chain is called non licensing chain
blockchain features
1, decentralization. Blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain
2. Openness. Blockchain technology is based on open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
3. Independence. Based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention
4. Safety. As long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily manipulated and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes
5. Anonymity. Unless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information can be transferred anonymously
2. In China, there are two. China blockchain research alliance, Zhongguancun blockchain instry alliance, China distributed general ledger infrastructure agreement alliance, financial blockchain alliance, China Internet Finance Association blockchain research group, blockchain micro finance instry alliance, Qianhai international blockchain alliance, interbank market blockchain technology research group, Lujiazui blockchain financial development alliance, International Wenwan blockchain instry alliance. Currency exchange digital currency exchange
3. Blockchain mainly solves the trust and security problems of transactions, so it proposes four technological innovations to solve this problem:
(1) distributed ledger, that is, transaction bookkeeping is completed by multiple nodes distributed in different places, and each node records complete accounts, so they can participate in monitoring the legitimacy of transactions, At the same time, they can testify together
different from traditional distributed storage, the uniqueness of distributed storage of blockchain is mainly reflected in two aspects: one is that each node of blockchain stores complete data according to block chain structure, while traditional distributed storage generally stores data in multiple copies according to certain rules. Second, the storage of each node in the blockchain is independent and has the same status, which relies on the consensus mechanism to ensure the consistency of storage, while the traditional distributed storage generally synchronizes data from the central node to other backup nodes[ 8]
no single node can record the account data separately, so as to avoid the possibility that a single bookkeeper is controlled or bribed to record false accounts. In theory, unless all the nodes are destroyed, the accounts will not be lost, so as to ensure the security of the account data
(2) asymmetric encryption and authorization technology, the transaction information stored on the blockchain is public, but the account identity information is highly encrypted, which can only be accessed under the authorization of the data owner, thus ensuring the data security and personal privacy
(3) consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and achieve a balance between efficiency and security
the consensus mechanism of blockchain has the characteristics of "the minority is subordinate to the majority" and "everyone is equal", in which "the minority is subordinate to the majority" does not completely refer to the number of nodes, but also can be the computing power, the number of shares or other characteristics that can be compared by computers“ "Everyone is equal" means that when the nodes meet the conditions, all nodes have the right to put forward the consensus results first, and then directly recognized by other nodes, and finally may become the final consensus results. Taking bitcoin as an example, the workload proof is adopted. Only when more than 51% of the accounting nodes in the whole network are controlled can a nonexistent record be forged. When there are enough nodes in the blockchain, this is basically impossible, thus eliminating the possibility of fraud.
(4) smart contract, which is based on these trusted and tamperable data, can automatically execute some pre-defined rules and terms. Take insurance as an example. If everyone's information (including medical information and risk occurrence information) is true and reliable, it is easy to carry out automatic claim settlement in some standardized insurance procts
(1) distributed ledger, that is, transaction bookkeeping is completed by multiple nodes distributed in different places, and each node records complete accounts, so they can participate in monitoring the legitimacy of transactions, At the same time, they can testify together
different from traditional distributed storage, the uniqueness of distributed storage of blockchain is mainly reflected in two aspects: one is that each node of blockchain stores complete data according to block chain structure, while traditional distributed storage generally stores data in multiple copies according to certain rules. Second, the storage of each node in the blockchain is independent and has the same status, which relies on the consensus mechanism to ensure the consistency of storage, while the traditional distributed storage generally synchronizes data from the central node to other backup nodes[ 8]
no single node can record the account data separately, so as to avoid the possibility that a single bookkeeper is controlled or bribed to record false accounts. In theory, unless all the nodes are destroyed, the accounts will not be lost, so as to ensure the security of the account data
(2) asymmetric encryption and authorization technology, the transaction information stored on the blockchain is public, but the account identity information is highly encrypted, which can only be accessed under the authorization of the data owner, thus ensuring the data security and personal privacy
(3) consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record, which is not only a means of identification, but also a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and achieve a balance between efficiency and security
the consensus mechanism of blockchain has the characteristics of "the minority is subordinate to the majority" and "everyone is equal", in which "the minority is subordinate to the majority" does not completely refer to the number of nodes, but also can be the computing power, the number of shares or other characteristics that can be compared by computers“ "Everyone is equal" means that when the nodes meet the conditions, all nodes have the right to put forward the consensus results first, and then directly recognized by other nodes, and finally may become the final consensus results. Taking bitcoin as an example, the workload proof is adopted. Only when more than 51% of the accounting nodes in the whole network are controlled can a nonexistent record be forged. When there are enough nodes in the blockchain, this is basically impossible, thus eliminating the possibility of fraud.
(4) smart contract, which is based on these trusted and tamperable data, can automatically execute some pre-defined rules and terms. Take insurance as an example. If everyone's information (including medical information and risk occurrence information) is true and reliable, it is easy to carry out automatic claim settlement in some standardized insurance procts
4. Now there is a good project in the inner row called ether mining
5. The disappearance should be temporary, just as newspapers are still there after Internet news. However, the new technology will certainly bring some impact or even impact. Blockchain may affect the following 12 instry regions:
1. Banking
as a digital, secure and anti-interference account, blockchain realizes the core function of Banking: the safe storage and transfer center of value. In other words, in the next few years, a wave of companies based on blockchain technology may affect the banking instry. Indeed, UBS, a Swiss company, and baecelays, a British company, are trying to use blockchain technology to improve payment terms. Some other banking companies even said blockchain technology could save $20 billion in intermediate costs
therefore, it is not surprising that banks, as financial service giants, have become the growth force of blockchain venture. Payment and transfer
recently, the world economic forum wrote in Forbes magazine that decentralized payment technology, such as bitcoin, may change the "business structure" of the transfer instry that has not changed for more than 100 years. Blockchain technology can avoid complex systems and create a more direct payment process between the payer and the payee. Whether it is domestic transfer or cross-border transfer, this method has the characteristics of low price, fast speed, and no intermediate fees. Abra (above) is a start-up enterprise that uses blockchain technology for global bitcoin and blockchain based transfer
3. Network security
although the system of blockchain is public, advanced encryption technology is used in the process of data exchange such as verification and transmission. This technology not only ensures the correct source of data, but also ensures that the data will not be intercepted in the intermediate process. If the application of blockchain technology is more extensive, the probability of being attacked by hackers may also decrease. Therefore, people think that blockchain system is more secure than traditional system. One of the reasons why blockchain system can rece the traditional network security risk is that it relieves the demand for middleman
"eliminating middlemen not only reces the potential security risk of hacker attacks, but also reces the possibility of corruption," Goldman Sachs wrote. Guardtime (above) is an Estonian start-up company, which mainly studies instrial network security solutions based on blockchain technology
4. Academic record and academia
holbertson school, a California software skills program, announced that it will use blockchain technology to identify academic credentials. This will ensure the authenticity of holbertson school students in course identification. If more schools adopt such transparent certificates, transcripts and diplomas, academic corruption will be greatly reced, not to mention the labor verification time and paper document cost
5. Elections
at the University of West Virginia, the student union is considering whether to use a voting platform based on blockchain technology to conct school elections. If such a platform is used, students can vote with mobile devices, and the voting results will be included in the public system, so the voting is completely safe. One student who supported this way explained that the vote "can never be modified or deleted by us - programmers, school administrators or students."
Agora voting, a Spanish software project, uses encryption technology to improve the security of online voting. Several of their systems have also been tested in Spain. Recently, the leader of this project proposed several ideas to turn bitcoin and blockchain technology into voting applications, which are far from experimental
6. Car rental and sales
later last year, visa and DocuSign announced a cooperative plan to create specific solutions for car rental by using blockchain technology. In the future, car rental can be completed in three steps of "click, sign and open". The specific operation is: customers choose the car they want to rent, and then the transaction will be uploaded to the public account of the blockchain; Then, the customer signs a lease agreement and an insurance agreement from the driver's seat, and the blockchain will upload the information in real time. It is not hard to imagine that this leasing model may also be applied to the field of car sales and car registration
7. Network communication and Internet of things
IBM and Samsung are working together to realize an idea called adept. Adept uses blockchain technology to build the pillar of decentralized Internet of things. Coindesk said that with adept, the decentralized P2P automatic telemetry system, the blockchain can become a public system for many devices, and there is no need for a central hub to mediate the communication of various devices. After removing the central control system and identifying each other, the devices can automatically communicate with each other, manage software updates, bugs, or energy consumption
other companies are also committed to integrating blockchain technology into the Internet of things platform. For example, filamen, which uses blockchain technology to build a decentralized network for sensor communication, announced that they have obtained US $5 million investment in round a financing, with the participation of Verizon ventures and Samsung ventures
8. Smart contract
a smart contract is actually a computer program that functions on the action of another object. Like ordinary computer programs, intelligent contracts are also an "If then" function, but blockchain technology realizes the automatic filling of these "contracts" without human intervention. This kind of contract may eventually replace the core business of the legal instry, that is, the business of drafting and managing contracts in the commercial and civil fields
for example, mortgage loans can be completed through blockchain technology and automatically executed every year according to the terms of the contract. Ethereum, a crowdfunding platform based on blockchain technology, not only provides decentralized applications, but also provides smart contracts. Some users have married with their smart contracts. Another company, hedgy, received $1.2 million in seed round investment from Tim Draper, Marc Benioff, boost.vc and sand hill angels earlier this year. The company uses smart contracts to build a platform for users to discuss the value of bitcoin
9. Prediction
blockchain technology may shake the whole research, analysis, consulting and prediction instry. Aug, an online crowdfunding platform, hopes to make a profit in a decentralized forecasting platform. The company said it would offer a service that looked like a gaming swap. The whole process will be decentralized, and the AUG platform will not only provide users with sports and stock gambling services, but also provide election and natural disaster gambling services. This idea actually goes beyond sports gambling and creates a "forecasting market"
10. Online music
many musicians are choosing blockchain technology to improve the fairness of online music sharing. Billboard reports that two companies are automatically solving licensing problems by paying artists directly and using smart contracts. Peertracks, which is still in its infancy, wants to create a new music streaming platform where users can pay artists directly without middleman's intervention. Peertracks also hopes to create more direct interaction between artists and users
ujo music, led by entrepreneur Phil Barry, claims that they are rebuilding the music instry on the blockchain. Ujo also hopes to solve the problem of streaming music and artist payment. In addition to streaming music, it is also expected that ujo will be able to better classify the artists and creators behind the songs by using intelligent contracts as the autonomous brain of the song list
11. Travel sharing
Uber and other travel applications seem to be on the opposite side of decentralization. This company is like a deployment center, using its algorithm to control its drivers and their charges. According to the report of blog, Israeli venture LA & # 39; Zooz wants to "go against Uber.". The company invented its own patented digital currency, which, like bitcoin, can be digitally recorded using blockchain technology. Different from the centralized network, users can call in LA & # 39; Find people with similar itinerary on zooz, and then use LA & # 39; Zooz's currency pays the taxi fare. These coins can be used for car hailing in the future. Users can get LA & # 39 as long as they allow the app to track their location; Zooz's digital currency
12. Stock trading
for many years, companies have been trying to simplify the process of stock purchase, sales and trading. Emerging blockchain technology makers believe that they can go beyond the past, realize the automation of the whole process, and improve security and efficiency. Overstock's subsidiary T & # Com wants to use blockchain technology to realize online trading of stocks. Overstock is already using blockchain technology to issue public shares, wired reported. At the same time, chain, a blockchain technology maker (mentioned above), is working with NASDAQ to realize the share trading of private companies through blockchain technology.
1. Banking
as a digital, secure and anti-interference account, blockchain realizes the core function of Banking: the safe storage and transfer center of value. In other words, in the next few years, a wave of companies based on blockchain technology may affect the banking instry. Indeed, UBS, a Swiss company, and baecelays, a British company, are trying to use blockchain technology to improve payment terms. Some other banking companies even said blockchain technology could save $20 billion in intermediate costs
therefore, it is not surprising that banks, as financial service giants, have become the growth force of blockchain venture. Payment and transfer
recently, the world economic forum wrote in Forbes magazine that decentralized payment technology, such as bitcoin, may change the "business structure" of the transfer instry that has not changed for more than 100 years. Blockchain technology can avoid complex systems and create a more direct payment process between the payer and the payee. Whether it is domestic transfer or cross-border transfer, this method has the characteristics of low price, fast speed, and no intermediate fees. Abra (above) is a start-up enterprise that uses blockchain technology for global bitcoin and blockchain based transfer
3. Network security
although the system of blockchain is public, advanced encryption technology is used in the process of data exchange such as verification and transmission. This technology not only ensures the correct source of data, but also ensures that the data will not be intercepted in the intermediate process. If the application of blockchain technology is more extensive, the probability of being attacked by hackers may also decrease. Therefore, people think that blockchain system is more secure than traditional system. One of the reasons why blockchain system can rece the traditional network security risk is that it relieves the demand for middleman
"eliminating middlemen not only reces the potential security risk of hacker attacks, but also reces the possibility of corruption," Goldman Sachs wrote. Guardtime (above) is an Estonian start-up company, which mainly studies instrial network security solutions based on blockchain technology
4. Academic record and academia
holbertson school, a California software skills program, announced that it will use blockchain technology to identify academic credentials. This will ensure the authenticity of holbertson school students in course identification. If more schools adopt such transparent certificates, transcripts and diplomas, academic corruption will be greatly reced, not to mention the labor verification time and paper document cost
5. Elections
at the University of West Virginia, the student union is considering whether to use a voting platform based on blockchain technology to conct school elections. If such a platform is used, students can vote with mobile devices, and the voting results will be included in the public system, so the voting is completely safe. One student who supported this way explained that the vote "can never be modified or deleted by us - programmers, school administrators or students."
Agora voting, a Spanish software project, uses encryption technology to improve the security of online voting. Several of their systems have also been tested in Spain. Recently, the leader of this project proposed several ideas to turn bitcoin and blockchain technology into voting applications, which are far from experimental
6. Car rental and sales
later last year, visa and DocuSign announced a cooperative plan to create specific solutions for car rental by using blockchain technology. In the future, car rental can be completed in three steps of "click, sign and open". The specific operation is: customers choose the car they want to rent, and then the transaction will be uploaded to the public account of the blockchain; Then, the customer signs a lease agreement and an insurance agreement from the driver's seat, and the blockchain will upload the information in real time. It is not hard to imagine that this leasing model may also be applied to the field of car sales and car registration
7. Network communication and Internet of things
IBM and Samsung are working together to realize an idea called adept. Adept uses blockchain technology to build the pillar of decentralized Internet of things. Coindesk said that with adept, the decentralized P2P automatic telemetry system, the blockchain can become a public system for many devices, and there is no need for a central hub to mediate the communication of various devices. After removing the central control system and identifying each other, the devices can automatically communicate with each other, manage software updates, bugs, or energy consumption
other companies are also committed to integrating blockchain technology into the Internet of things platform. For example, filamen, which uses blockchain technology to build a decentralized network for sensor communication, announced that they have obtained US $5 million investment in round a financing, with the participation of Verizon ventures and Samsung ventures
8. Smart contract
a smart contract is actually a computer program that functions on the action of another object. Like ordinary computer programs, intelligent contracts are also an "If then" function, but blockchain technology realizes the automatic filling of these "contracts" without human intervention. This kind of contract may eventually replace the core business of the legal instry, that is, the business of drafting and managing contracts in the commercial and civil fields
for example, mortgage loans can be completed through blockchain technology and automatically executed every year according to the terms of the contract. Ethereum, a crowdfunding platform based on blockchain technology, not only provides decentralized applications, but also provides smart contracts. Some users have married with their smart contracts. Another company, hedgy, received $1.2 million in seed round investment from Tim Draper, Marc Benioff, boost.vc and sand hill angels earlier this year. The company uses smart contracts to build a platform for users to discuss the value of bitcoin
9. Prediction
blockchain technology may shake the whole research, analysis, consulting and prediction instry. Aug, an online crowdfunding platform, hopes to make a profit in a decentralized forecasting platform. The company said it would offer a service that looked like a gaming swap. The whole process will be decentralized, and the AUG platform will not only provide users with sports and stock gambling services, but also provide election and natural disaster gambling services. This idea actually goes beyond sports gambling and creates a "forecasting market"
10. Online music
many musicians are choosing blockchain technology to improve the fairness of online music sharing. Billboard reports that two companies are automatically solving licensing problems by paying artists directly and using smart contracts. Peertracks, which is still in its infancy, wants to create a new music streaming platform where users can pay artists directly without middleman's intervention. Peertracks also hopes to create more direct interaction between artists and users
ujo music, led by entrepreneur Phil Barry, claims that they are rebuilding the music instry on the blockchain. Ujo also hopes to solve the problem of streaming music and artist payment. In addition to streaming music, it is also expected that ujo will be able to better classify the artists and creators behind the songs by using intelligent contracts as the autonomous brain of the song list
11. Travel sharing
Uber and other travel applications seem to be on the opposite side of decentralization. This company is like a deployment center, using its algorithm to control its drivers and their charges. According to the report of blog, Israeli venture LA & # 39; Zooz wants to "go against Uber.". The company invented its own patented digital currency, which, like bitcoin, can be digitally recorded using blockchain technology. Different from the centralized network, users can call in LA & # 39; Find people with similar itinerary on zooz, and then use LA & # 39; Zooz's currency pays the taxi fare. These coins can be used for car hailing in the future. Users can get LA & # 39 as long as they allow the app to track their location; Zooz's digital currency
12. Stock trading
for many years, companies have been trying to simplify the process of stock purchase, sales and trading. Emerging blockchain technology makers believe that they can go beyond the past, realize the automation of the whole process, and improve security and efficiency. Overstock's subsidiary T & # Com wants to use blockchain technology to realize online trading of stocks. Overstock is already using blockchain technology to issue public shares, wired reported. At the same time, chain, a blockchain technology maker (mentioned above), is working with NASDAQ to realize the share trading of private companies through blockchain technology.
6. When it's turned off, it will still turn on automatically. It needs to be turned off manually. If it doesn't, turn on the traffic directly. When you click system update, it will turn off automatically. Because the system update file is too large, when you turn on the traffic, it will show that the traffic is too large, and you won't download the system update installation package. Finally, you must turn off the automatic downloading of system updates under WiFi.
7. 3S technology is the general name of remote sensing (RS), geographic information systems (GIS) and global positioning systems (GPS). It is the combination of space technology, sensor technology, satellite positioning and navigation technology, computer technology and communication technology, Multi disciplinary highly integrated modern information technology for spatial information collection, processing, management, analysis, expression, dissemination and application. 3S technology is the forerunner of modern technology development, plays an important role in the progress of science and technology all over the world, and also has a very wide range of applications in the field of agriculture.
8. Blockchain is the underlying technology of bitcoin. You can think of blockchain as a distributed database for storing bitcoin transactions. In the whole network, each node will have a complete blockchain
blockchain technology has realized the key characteristics of tamper proof, decentralization, anonymity, security and reliability. Now more and more instries choose to use blockchain technology. For example, NASDAQ has adopted blockchain technology to realize LINQ, a private equity trading platform. It is more secure, and the transactions stored in the blockchain can not be tampered with, that is to say, once written, it is impossible to be modified. In the future, the application of blockchain will be very wide, and all aspects can be applied to blockchain technology. For example, in the future, schools can store the electronic version of Graation Certificate in the blockchain, which will not be tampered with. Employers can check the authenticity of students' graation certificate by querying the information in the blockchain.
blockchain technology has realized the key characteristics of tamper proof, decentralization, anonymity, security and reliability. Now more and more instries choose to use blockchain technology. For example, NASDAQ has adopted blockchain technology to realize LINQ, a private equity trading platform. It is more secure, and the transactions stored in the blockchain can not be tampered with, that is to say, once written, it is impossible to be modified. In the future, the application of blockchain will be very wide, and all aspects can be applied to blockchain technology. For example, in the future, schools can store the electronic version of Graation Certificate in the blockchain, which will not be tampered with. Employers can check the authenticity of students' graation certificate by querying the information in the blockchain.
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