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Blockchain ledger
Publish: 2021-03-28 12:34:03
1. blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain is essentially a decentralized database
for example, if you are a woman, every time your boyfriend says something disgusting to you or promises to buy something for you, you immediately record it and send it to you and all his friends, classmates, colleagues, as well as various groups and circles of friends, so that he can no longer resist. This is called blockchain
the core advantage of blockchain technology is decentralization, which can realize point-to-point transaction, coordination and cooperation based on decentralized credit in a distributed system without mutual trust by means of data encryption, time stamp, distributed consensus and economic incentive, so as to solve the high cost and low cost of centralized institutions Low efficiency and data storage insecurity provide solutions
the application fields of blockchain include digital currency, token, finance, anti-counterfeiting traceability, privacy protection, supply chain, entertainment, etc. with the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry.
for example, if you are a woman, every time your boyfriend says something disgusting to you or promises to buy something for you, you immediately record it and send it to you and all his friends, classmates, colleagues, as well as various groups and circles of friends, so that he can no longer resist. This is called blockchain
the core advantage of blockchain technology is decentralization, which can realize point-to-point transaction, coordination and cooperation based on decentralized credit in a distributed system without mutual trust by means of data encryption, time stamp, distributed consensus and economic incentive, so as to solve the high cost and low cost of centralized institutions Low efficiency and data storage insecurity provide solutions
the application fields of blockchain include digital currency, token, finance, anti-counterfeiting traceability, privacy protection, supply chain, entertainment, etc. with the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry.
2. That's a good question. Let me give you an example. For example, when I deposit 100 yuan in the bank, the data of this deposit is only recorded in the bank's database, which can't be obtained by others, namely "central bookkeeping". The blockchain is a distributed accounting, a new information recording technology, and it is "encrypted" and "distributed". The data does not exist in a center, but is stored once on the computer of the whole network. For example, if I transfer 100 yuan to you, I will shout to all the computers in the whole network. Let's record the accounts together, that is, "Distributed Accounting".
3. const SHA256 = require(crypto-js/SHA256);< br />class Block{
constructor(index,timestamp,data,previousHash='&# 39;)< br />{
this.index=index;< br />this.timestamp=timestamp;< br />this.data=data;< br />this.previousHash=previousHash;< br />$this.hash=this.calculateHash();< br />}
calculateHash(){
return SHA256(this,index+this.previousHash+this.timestamp+JSON.stringify(this.data)).tostring();< br />}
}
class Blockchain{
constructor(){
this.chain=[this.createGenesisBlock()];<
}
/ / create a generated information block
creategenesis block() {
return new block (0, & quot; 01/01/2019",& quot; Genesis block", 0);
/ / the date is the user's data. In fact, it is the hash value obtained by adding several values together. Here, the information is encrypted and the picture is encrypted. Then the data is still stored in the database, but all the data are hash values. To get this data, you must know the hash value of the previous data block. Then, if the hacker needs to crack all the nodes, the hash value is decrypted, Then all the blocks from the first node to the last node can be decrypted to get the real data. So the security of data stored in the blockchain depends on whether the data is encrypted. If the plaintext is not encrypted, then it is not a blockchain
}
/ / get the last block
getlatesblock() {
return this.chain [this.chain. Length-1]
}
/ / create block
addblock (newblock) {
newblock. Previoushash = this. Getlatesblock(). Hash< br />newBlock.hash=newBlock.calculateHash();< br />this.chain.push(newBlock);< br />}
}
constructor(index,timestamp,data,previousHash='&# 39;)< br />{
this.index=index;< br />this.timestamp=timestamp;< br />this.data=data;< br />this.previousHash=previousHash;< br />$this.hash=this.calculateHash();< br />}
calculateHash(){
return SHA256(this,index+this.previousHash+this.timestamp+JSON.stringify(this.data)).tostring();< br />}
}
class Blockchain{
constructor(){
this.chain=[this.createGenesisBlock()];<
}
/ / create a generated information block
creategenesis block() {
return new block (0, & quot; 01/01/2019",& quot; Genesis block", 0);
/ / the date is the user's data. In fact, it is the hash value obtained by adding several values together. Here, the information is encrypted and the picture is encrypted. Then the data is still stored in the database, but all the data are hash values. To get this data, you must know the hash value of the previous data block. Then, if the hacker needs to crack all the nodes, the hash value is decrypted, Then all the blocks from the first node to the last node can be decrypted to get the real data. So the security of data stored in the blockchain depends on whether the data is encrypted. If the plaintext is not encrypted, then it is not a blockchain
}
/ / get the last block
getlatesblock() {
return this.chain [this.chain. Length-1]
}
/ / create block
addblock (newblock) {
newblock. Previoushash = this. Getlatesblock(). Hash< br />newBlock.hash=newBlock.calculateHash();< br />this.chain.push(newBlock);< br />}
}
4. It depends on the project. Take bitcoin as an example. Now the account book that records all the information of bitcoin network may reach 220g.
5. Blockchain technology will not affect efficiency and waste computing power. The key is to see how to innovate in a mode and how to use blockchain technology efficiently to achieve the effect of the mode
blockchain is essentially an encryption algorithm, which is based on the principle of hash 256 bit algorithm to achieve information security; The application of modern information will become more and more global and universal. Besides the basic requirements of anti tampering, anti repudiation and trustworthiness, the protection of privacy needs to be strengthened. The blockchain technology is proced because of the development of modern cryptography. The cryptography used today is the result of cryptography 20 years ago, Therefore, in order to apply the blockchain technology to more participation scenarios, especially in the Internet economy, more verification is needed to verify whether the existing encryption technology can meet the demand, and more in-depth integration of cryptographic frontier technology and continuous innovation are needed
as long as we use blockchain to make innovations in accounting methods based on our own mode, it will not affect efficiency and waste computing power, but will shorten the time and improve efficiency.
blockchain is essentially an encryption algorithm, which is based on the principle of hash 256 bit algorithm to achieve information security; The application of modern information will become more and more global and universal. Besides the basic requirements of anti tampering, anti repudiation and trustworthiness, the protection of privacy needs to be strengthened. The blockchain technology is proced because of the development of modern cryptography. The cryptography used today is the result of cryptography 20 years ago, Therefore, in order to apply the blockchain technology to more participation scenarios, especially in the Internet economy, more verification is needed to verify whether the existing encryption technology can meet the demand, and more in-depth integration of cryptographic frontier technology and continuous innovation are needed
as long as we use blockchain to make innovations in accounting methods based on our own mode, it will not affect efficiency and waste computing power, but will shorten the time and improve efficiency.
6. Blockchain is a decentralized distributed record book and a credit data system. Its advantages are obvious
1. What the Internet changes is the acquisition and transmission of information, while what blockchain does is the transmission of value
for example, on the Internet, we can easily and quickly generate information and it to any place. All information can be spread efficiently, but some valuable information that can only be transferred but cannot be shared often needs credit endorsement
for example, we can't the payment directly to the other party, but we need to subtract some money from the payment account and add some money to the collection account to complete the payment process. The current Internet protocol does not support the function of value transfer. The current value transfer is not direct transmission. Instead, it is endorsed by a centralized third party, such as Alipay, such as banks.
now these centralized organizations put all the calculation of value transfer in a centralized server, which will certainly involve the participation of people, which will cause many problems, such as some "finite theory" and "opportunistic behavior", which will make the whole behavior less credible. So there is a basic question, how to reach a credit consensus
this is how blockchain technology came into being. It can be said that blockchain can build a pure point-to-point value transfer system. Without the mutual trust of each node, blockchain can ensure the integrity and security of data records in the system, and can be separated from the endorsement of third-party organizations, effectively recing the complexity and risk of transactions
2. It is open and transparent, and can not be tampered with
all data of the blockchain can not be tampered with or deleted, and the information of the whole system is open and transparent. If someone owes you a sum of money, and now the data has been put on the blockchain, if he doesn't want to return it to you and play a rogue with you, you can go to the court to protect your rights through the data forensics on the blockchain, so as to get back your legitimate funds. Because the data on the blockchain is open to the whole network, the users of the whole network will know his rogue behavior, which will greatly increase his credit cost. Dishonesty will make him have an important impact in the next life.
1. What the Internet changes is the acquisition and transmission of information, while what blockchain does is the transmission of value
for example, on the Internet, we can easily and quickly generate information and it to any place. All information can be spread efficiently, but some valuable information that can only be transferred but cannot be shared often needs credit endorsement
for example, we can't the payment directly to the other party, but we need to subtract some money from the payment account and add some money to the collection account to complete the payment process. The current Internet protocol does not support the function of value transfer. The current value transfer is not direct transmission. Instead, it is endorsed by a centralized third party, such as Alipay, such as banks.
now these centralized organizations put all the calculation of value transfer in a centralized server, which will certainly involve the participation of people, which will cause many problems, such as some "finite theory" and "opportunistic behavior", which will make the whole behavior less credible. So there is a basic question, how to reach a credit consensus
this is how blockchain technology came into being. It can be said that blockchain can build a pure point-to-point value transfer system. Without the mutual trust of each node, blockchain can ensure the integrity and security of data records in the system, and can be separated from the endorsement of third-party organizations, effectively recing the complexity and risk of transactions
2. It is open and transparent, and can not be tampered with
all data of the blockchain can not be tampered with or deleted, and the information of the whole system is open and transparent. If someone owes you a sum of money, and now the data has been put on the blockchain, if he doesn't want to return it to you and play a rogue with you, you can go to the court to protect your rights through the data forensics on the blockchain, so as to get back your legitimate funds. Because the data on the blockchain is open to the whole network, the users of the whole network will know his rogue behavior, which will greatly increase his credit cost. Dishonesty will make him have an important impact in the next life.
7. The three levels are pyramid type, and several switches are connected below the core layer. If the core ports are not enough, they need to be stacked
our school's core uses Nortel 8610, and the expansion only needs to add interfaces. Generally, the core is tested by moles, and adding ports only needs to add moles instead of stacking
an optical switch can be connected under the core, and several layer-2 switches can be connected under the optical switch, which can also save the core port, rece the cost and increase the network users
the specific situation also depends on whether the ports of your core are enough, as well as the core bandwidth, the number of convergence layers, and so on.
our school's core uses Nortel 8610, and the expansion only needs to add interfaces. Generally, the core is tested by moles, and adding ports only needs to add moles instead of stacking
an optical switch can be connected under the core, and several layer-2 switches can be connected under the optical switch, which can also save the core port, rece the cost and increase the network users
the specific situation also depends on whether the ports of your core are enough, as well as the core bandwidth, the number of convergence layers, and so on.
8.
This is a data center switch, which supports virtualization, that is VSU. Configuration reference
core switch 1:
Switch1 # configuration terminal
enter configuration commands, one per line. End with cntl / Z.
Switch1 (config) # switch virtual domain 1
Switch1 (config vs domain) # switch 1
Switch1 (config vs domain) # switch 1 priority 200 -- & gt; The default priority is 100, which is configured as a higher priority. After the VSU is successfully established, it will become the management host
Switch1(config-vs-domain)# exit
Switch1(config)# vsl-aggregateport 1 ------> At least two VSL links are needed, and the reliability of one link is low. When link oscillation occurs, VSU will be very unstable
Switch1(config-vsl-ap-1)# port-member interface TenGigabitEthernet 1/1 ------> Configure VSL link, heartbeat link and traffic channel between VSU active and standby cores
Switch1 (config-vsl-ap-1) ﹥ port member interface tengigabit Ethernet 1 / 2
Switch1 (config-vsl-ap-1) ﹥ exit
core switch 2:
switch2 ﹥ configuration terminal
enter configuration commands, one per line. End with CNTL/Z.
Switch2(config)# switch virtual domain 1 ------> Domain ID must be consistent with the first one
switch2 (config vs domain) # switch 2 ----- & gt; The second device must change its ID to 2
switch2 (config vs domain) ｛ switch 2 priority 150
switch2 (config vs domain) ｛ exit
switch2 (config) ｛ VSL aggregateport 1 ----- & gt; At least two VSL links are needed, and the reliability of one link is low. When link oscillation occurs, VSU will be very unstable
Switch2(config-vsl-ap-1)# port-member interface TenGigabitEtherne 1/1 ------> Configure VSL link, heartbeat link and traffic channel between VSU active and standby cores
switch2 (config-vsl-ap-1) # port member interface tengigabit Ethernet 1 / 2
switch2 (config-vsl-ap-1) # exit
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