Hash value BTC
Publish: 2021-03-29 15:15:01
1. In order to understand the technical principle of bitcoin, we need to understand two important cryptographic techniques: hash code: it converts a long string into a fixed length string, and its conversion is irreversible, that is, it is impossible to guess the original string from hash code. Sha256 is mainly used in bitcoin protocol
public key system: corresponds to a public key and a private key, keeps the private key in the application and publishes the public key. When Party A transmits information to Party B, it can use Party A's private key to encrypt the information, and Party B can use Party A's public key to decrypt the information, so as to ensure that the third party cannot impersonate Party A to send the information; At the same time, when Party A transmits information to Party B, it is encrypted with Party B's public key and sent to Party B, and then Party B decrypts it with his own private key, so as to ensure that the third party cannot eavesdrop on the communication between the two people. RSA is the most common public key system, but the lliptic curve digital signature algorithm is used in bitcoin protocol. What's the difference between cash and bank account? Bitcoin is an electronic currency in BTC. In this article, it is also used to refer to the whole bitcoin system. Like opening an account in a bank, the corresponding concept in bitcoin is address. Everyone can have one or more bitcoin addresses, which are used to pay and collect money. Each address is a string that starts with 1. For example, I have two bitcoin accounts, and. A bitcoin account is uniquely determined by a pair of public key and private key. To save the account, you only need to save the private key file. Unlike bank accounts, banks keep all transaction records and maintain the book balance of each account, while bitcoin's transaction records are jointly maintained by the whole P2P network through a pre agreed protocol. How much money is in my account address? Although the current account balance can be seen by bitcoin software, unlike banks, there is no place to maintain the book balance of each address. It can only calculate the account balance in real time through all historical transactions. How do I pay? When I pay from address a to address B of the other party, the payment amount is e. at this time, both parties will announce the transaction information to each network node, telling address a to pay to address B, and the payment amount is e. In order to prevent the third party from forging the transaction information, the transaction information will be encrypted with the private key of address A. at this time, the network node receiving the transaction information can use the public key of address a to verify that the transaction information is indeed sent by address a. Of course, trading software will help us do these things, we just need to input the relevant parameters in the software. What will the network node do after receiving the transaction information? This is the most important part of the bitcoin system, which needs to be elaborated. For the sake of simplicity, only bitcoin protocol has been implemented. In the current version, each network node will save all transaction information synchronously. There are two kinds of transaction information in history, one is & quot; Verified & quot; The transaction information, that is, the verified transaction information, is stored in a series of "blocks". Each & quot; block" Is the previous & quot; bock" The ID of each block is the hash code of the hash code of the block and the new transaction information (see an actual block). The other category refers to those who also & quot; Unverified & quot; The transaction information just paid above belongs to this category. When a network node receives new unverified transaction information (possibly more than one), it can calculate the book balance of each address at that time because the node keeps all the transaction information in history, so it can calculate whether the transaction information is valid, that is, whether there is enough balance in the payment account. After eliminating the invalid transaction information, it first takes out the last & quot; block" Then, the unverified transaction information is combined with the ID, and a verification code is added to form a new "block". It needs a lot of calculation to build a new block, because it needs to calculate the verification code, so that the above combination becomes a block, that is, the first several bits of the hash code of the block are 1. At present, the first 13 bits need to be 1 (generally, the specific method is uncertain), which means that if the block is generated by enumeration method, the average number of enumerations is 16 ^ 13. Using CPU resources to generate a block is called "gold mining", because the proction of the block will get a certain reward, and the reward information has been included in the block. When a network node generates a new block, it will broadcast to other network nodes. However, this network block may not be accepted by the network, because it is possible that other network nodes have proced the block earlier. Only the earliest block or the block with the largest number of subsequent blocks is valid, and the remaining blocks are no longer used as the initial blocks of the next block. How does the other party confirm that the payment is successful? When the payment information is distributed to the network node, the network node begins to calculate whether the transaction is valid (that is, whether the account balance is enough to pay), and attempts to generate blocks containing the transaction information. When six blocks (one direct block and five subsequent blocks) contain the transaction information, the transaction information is considered "verified", so that the transaction is formally confirmed, and the other party can confirm the successful payment. A possible problem is that I will pay the balance of address a to address B, and at the same time pay to address C. If I only verify that the single comparison transaction is valid. At this point, my way of cheating is to generate six blocks including B to B and six blocks including C to C before the truth is revealed. Because I need a very long CPU time to generate a block, compared with the whole network, the probability of my cheating success is very small. What is the motivation of network nodes to proce blocks? As can be seen from the above description, in order to make the transaction information effective, the network node needs to generate 1 and 5 subsequent blocks to contain the transaction information, and such block generation is very CPU intensive. How to let other network nodes help to proce blocks as soon as possible? The answer is very simple. The agreement stipulates that BTC will be rewarded for the address where the block is proced, as well as the Commission promised by both parties. At present, the reward for procing a block is 50btc, which will be halved every four years in the future. For example, the reward will be 25btc from 2013 to 2016. Is the transaction anonymous? Yes, and No. All bitcoin transactions are visible. We can check all transaction records of each account, such as mine. But what's different from the banking monetary system is that everyone's account itself is anonymous, and everyone can open many accounts. In general, anonymity is not as good as it claims. But bitcoin has another advantage in doing black market trading: it can't be frozen. Even if the police trace a bitcoin address, there is nothing they can do unless they trace the computer used by the exchange based on the Internet address. How to ensure that bitcoin does not depreciate? Generally speaking, in the case of equivalent trading activities, the value of money is inversely proportional to the amount of money issued. Unlike the traditional money market, the central bank can determine the amount of money issued. Bitcoin does not have a central issuing institution. Only by procing blocks can we get a certain amount of BTC currency. Therefore, bitcoin's new amount of money depends on: 1. The speed of procing blocks: bitcoin's agreement stipulates that the difficulty of procing blocks is fixed at an average of 2016 every two weeks, about 10 minutes. Moore's law of doubling CPU speed every 18 months will not speed up the proction of block. 2. The number of rewards for block proction: at present, 50 BTC is awarded for each block proced, which is halved every four years. In 2013, 25 BTC is awarded, and in 2017, 12.5 BTC is awarded. Considering the above two factors, bitcoin's currency issuing speed is not controlled by any single node in the network. Its protocol makes the currency stock known in advance, and the maximum stock is only 21 million BTC
public key system: corresponds to a public key and a private key, keeps the private key in the application and publishes the public key. When Party A transmits information to Party B, it can use Party A's private key to encrypt the information, and Party B can use Party A's public key to decrypt the information, so as to ensure that the third party cannot impersonate Party A to send the information; At the same time, when Party A transmits information to Party B, it is encrypted with Party B's public key and sent to Party B, and then Party B decrypts it with his own private key, so as to ensure that the third party cannot eavesdrop on the communication between the two people. RSA is the most common public key system, but the lliptic curve digital signature algorithm is used in bitcoin protocol. What's the difference between cash and bank account? Bitcoin is an electronic currency in BTC. In this article, it is also used to refer to the whole bitcoin system. Like opening an account in a bank, the corresponding concept in bitcoin is address. Everyone can have one or more bitcoin addresses, which are used to pay and collect money. Each address is a string that starts with 1. For example, I have two bitcoin accounts, and. A bitcoin account is uniquely determined by a pair of public key and private key. To save the account, you only need to save the private key file. Unlike bank accounts, banks keep all transaction records and maintain the book balance of each account, while bitcoin's transaction records are jointly maintained by the whole P2P network through a pre agreed protocol. How much money is in my account address? Although the current account balance can be seen by bitcoin software, unlike banks, there is no place to maintain the book balance of each address. It can only calculate the account balance in real time through all historical transactions. How do I pay? When I pay from address a to address B of the other party, the payment amount is e. at this time, both parties will announce the transaction information to each network node, telling address a to pay to address B, and the payment amount is e. In order to prevent the third party from forging the transaction information, the transaction information will be encrypted with the private key of address A. at this time, the network node receiving the transaction information can use the public key of address a to verify that the transaction information is indeed sent by address a. Of course, trading software will help us do these things, we just need to input the relevant parameters in the software. What will the network node do after receiving the transaction information? This is the most important part of the bitcoin system, which needs to be elaborated. For the sake of simplicity, only bitcoin protocol has been implemented. In the current version, each network node will save all transaction information synchronously. There are two kinds of transaction information in history, one is & quot; Verified & quot; The transaction information, that is, the verified transaction information, is stored in a series of "blocks". Each & quot; block" Is the previous & quot; bock" The ID of each block is the hash code of the hash code of the block and the new transaction information (see an actual block). The other category refers to those who also & quot; Unverified & quot; The transaction information just paid above belongs to this category. When a network node receives new unverified transaction information (possibly more than one), it can calculate the book balance of each address at that time because the node keeps all the transaction information in history, so it can calculate whether the transaction information is valid, that is, whether there is enough balance in the payment account. After eliminating the invalid transaction information, it first takes out the last & quot; block" Then, the unverified transaction information is combined with the ID, and a verification code is added to form a new "block". It needs a lot of calculation to build a new block, because it needs to calculate the verification code, so that the above combination becomes a block, that is, the first several bits of the hash code of the block are 1. At present, the first 13 bits need to be 1 (generally, the specific method is uncertain), which means that if the block is generated by enumeration method, the average number of enumerations is 16 ^ 13. Using CPU resources to generate a block is called "gold mining", because the proction of the block will get a certain reward, and the reward information has been included in the block. When a network node generates a new block, it will broadcast to other network nodes. However, this network block may not be accepted by the network, because it is possible that other network nodes have proced the block earlier. Only the earliest block or the block with the largest number of subsequent blocks is valid, and the remaining blocks are no longer used as the initial blocks of the next block. How does the other party confirm that the payment is successful? When the payment information is distributed to the network node, the network node begins to calculate whether the transaction is valid (that is, whether the account balance is enough to pay), and attempts to generate blocks containing the transaction information. When six blocks (one direct block and five subsequent blocks) contain the transaction information, the transaction information is considered "verified", so that the transaction is formally confirmed, and the other party can confirm the successful payment. A possible problem is that I will pay the balance of address a to address B, and at the same time pay to address C. If I only verify that the single comparison transaction is valid. At this point, my way of cheating is to generate six blocks including B to B and six blocks including C to C before the truth is revealed. Because I need a very long CPU time to generate a block, compared with the whole network, the probability of my cheating success is very small. What is the motivation of network nodes to proce blocks? As can be seen from the above description, in order to make the transaction information effective, the network node needs to generate 1 and 5 subsequent blocks to contain the transaction information, and such block generation is very CPU intensive. How to let other network nodes help to proce blocks as soon as possible? The answer is very simple. The agreement stipulates that BTC will be rewarded for the address where the block is proced, as well as the Commission promised by both parties. At present, the reward for procing a block is 50btc, which will be halved every four years in the future. For example, the reward will be 25btc from 2013 to 2016. Is the transaction anonymous? Yes, and No. All bitcoin transactions are visible. We can check all transaction records of each account, such as mine. But what's different from the banking monetary system is that everyone's account itself is anonymous, and everyone can open many accounts. In general, anonymity is not as good as it claims. But bitcoin has another advantage in doing black market trading: it can't be frozen. Even if the police trace a bitcoin address, there is nothing they can do unless they trace the computer used by the exchange based on the Internet address. How to ensure that bitcoin does not depreciate? Generally speaking, in the case of equivalent trading activities, the value of money is inversely proportional to the amount of money issued. Unlike the traditional money market, the central bank can determine the amount of money issued. Bitcoin does not have a central issuing institution. Only by procing blocks can we get a certain amount of BTC currency. Therefore, bitcoin's new amount of money depends on: 1. The speed of procing blocks: bitcoin's agreement stipulates that the difficulty of procing blocks is fixed at an average of 2016 every two weeks, about 10 minutes. Moore's law of doubling CPU speed every 18 months will not speed up the proction of block. 2. The number of rewards for block proction: at present, 50 BTC is awarded for each block proced, which is halved every four years. In 2013, 25 BTC is awarded, and in 2017, 12.5 BTC is awarded. Considering the above two factors, bitcoin's currency issuing speed is not controlled by any single node in the network. Its protocol makes the currency stock known in advance, and the maximum stock is only 21 million BTC
2. What is hash algorithm? How to ensure the fairness of mining
hash algorithm is a cryptographic algorithm that can only encrypt, but not decrypt. It can convert any length of information into a fixed length string
this string has two characteristics:
1. Even if the input value changes only a little, the output hash value will be very different
2. Only exactly the same input value can get exactly the same output value
3. There is no rule between the input value and the output value, so the input value cannot be calculated by the output value. In order to find the specified output value, we can only use enumeration method: constantly change the input value to find the output value that meets the conditions
hash algorithm ensures that the results of bitcoin mining can not be deced reversely. Therefore, the miner's continuous operation is essentially brutally cracking the correct input value. Whoever finds the first one will get the bitcoin reward.
hash algorithm is a cryptographic algorithm that can only encrypt, but not decrypt. It can convert any length of information into a fixed length string
this string has two characteristics:
1. Even if the input value changes only a little, the output hash value will be very different
2. Only exactly the same input value can get exactly the same output value
3. There is no rule between the input value and the output value, so the input value cannot be calculated by the output value. In order to find the specified output value, we can only use enumeration method: constantly change the input value to find the output value that meets the conditions
hash algorithm ensures that the results of bitcoin mining can not be deced reversely. Therefore, the miner's continuous operation is essentially brutally cracking the correct input value. Whoever finds the first one will get the bitcoin reward.
3. Litecoin litecoin (LTC), released on October 7, 2011, is currently the most valuable counterfeit coin, accounting for about 2% of BTC's market value. The current unit price is US $2.31, with a total currency value of US $38 million. It's also a distributed (decentralized) digital currency. Unlike the sha256 mining algorithm used by bitcoin, LTC adopts scrypt algorithm. Scrypt algorithm uses sha256 as its subroutine, and scrypt itself needs a lot of memory. Each hash is used as the seed of the input, and then it needs a lot of memory to store another pseudo-random sequence to generate the pseudo-random points of the sequence and output the hash value. In the mining of BTC (bitcoin), it is not enough to rely on simple graphics card mining (it takes about ten to dozens of days to dig a BTC with general configuration graphics card). The emergence of various expensive mining machines has raised the threshold for ordinary people to get BTC through mining, while LTC has certain advantages in using PC graphics card mining This passage comes from Zhihu.) Compared with BTC, litecoin has made a little improvement in technology. If BTC is gold now, LTC is silver for the time being. The biggest advantage of litecoin is that it can confirm the authenticity faster. The virtual currency is designed and maintained by Charles Lee. Bitcoin transactions need to be verified, and the average verification time is more than 10 minutes. Most transaction websites need 1 hour to verify. The average transaction confirmation time of liteoin is 2.5 minutes. Developers claim that shortening the verification time increases the practicability of virtual currency. The bitcoin mining efficiency of customized machine and amdgpu is the highest, making it almost unprofitable for miners using CPU mining. Litecain's mining excludes GPUs and custom processors, so it doesn't rely too much on a small number of professional miners. Ppcoinppcoin (PPC) was released on August 19, 2012, which has improved the original technology of BTC. Use proof of stack and join the concept of coinage. Ppcoin is a bifurcated project of bitcoin, which aims to achieve energy efficiency and keep the best performance of the original bitcoin as far as possible. The unit price of ppcoin is US $0.22 and the total currency value is US $4 million. Ppcoin does not have a fixed upper limit of money supply, but it does not mean that ppcoin has obvious inflation compared with bitcoin. Bitcoin can be compared to gold. The annual inflation rate of gold is about 1-3%. Although gold has no known upper limit of money supply, we still know that it is a reliable scarce commodity. There are two types of ppcoin casting: work certificate and equity certificate. The coinage rate of working proof is affected by Moore's law, which depends on the doubling of our working proof ability. What we all know is that Moore's law will eventually come to an end. By then, the ppcoin of inflation may be close to the gold level. The annual maximum inflation rate of certificate of equity is 1%. At the same time, ppcoin's transaction costs were destroyed to fight inflation. So on the whole, the coin design of ppcoin is still a very low inflation design in the future, which can be comparable with bitcoin. Ppcoin is awarded in a lottery like way, and the winning probability is determined by the number of ppcoins held by miners, said sunny king, one of the founders. Their design is based on a new concept of long-term energy efficiency. Terracoin terracoin (TRC) was released on October 26, 2012, with a total currency of 42 million. The speed of each block is 2 minutes, slightly faster than LTC. There is not much special in technology, similar to the proction of BTC halved every four years. However, the operation team seems to have a strong business background and may be better than other bitcoin in circulation. The development of virtual currency is getting more and more attention. Now some teams with business background will accelerate the development of virtual currency. Namecoin namecoin is a distributed domain name system based on bitcoin technology. Its principle is the same as bitcoin. This open source software was first released on April 18, 2011. Namecoin is generated from an original block which is different from bitcoin's main trading block. It uses a new blockchain, which is independent of bitcoin's blockchain. Because it is based on bitcoin, the security, distribution, robustness, encryption and migration of domain names are mathematically guaranteed. You can dig bitcoin and namecoin at the same time. This project was discussed and proposed by bitdns, which is mainly dissatisfied with the defects of DNS. The only top-level domain name of namecoin is. Bit. It costs namecoin to register a. Bit domain name.
4.
renrenfu financial and business school tells you that every bitcoin node will collect all unconfirmed transactions and gather them into a data block, which will be integrated with the previous data block. The miner node will attach a random adjustment number and calculate the SHA-256 hash value of the previous data block. The mining node keeps trying again and again until it finds the random adjustment number so that the generated hash value is lower than a specific target
because hash operation is irreversible, it is very difficult to find the required random adjustment number, which requires a continuous trial and error process that can predict the total number. At this time, the workload proof mechanism will play a role. When a node finds a satisfactory solution, it can broadcast its results to the whole network. Other nodes can receive the new data block and check whether it meets the specification. If other nodes do meet the requirements by calculating the hash value, then the data block is valid, and other nodes will accept the data block and attach it to their own chain
bitcoin mining uses SHA-256 hash value operation. This algorithm will carry out a large number of 32-bit integer circular right shift operations
exhaustive verification until it finds a data that meets the requirements. This meaningless data is a dollar
5. Blockchain is composed of a series of block links generated by cryptographic algorithm, so it is called blockchain
each block is filled with transaction records, and the blocks are connected in sequence to form a chain structure, which is the blockchain ledger
blockchain technology divides the data to be stored in the database into different blocks. Taking bitcoin as an example, when miners generate new blocks, they need to calculate the new hash value and random number according to the hash value of the previous block, the new transaction block and the random number. Each block is linked to the back of the previous block through specific information, and connected in chronological order to present a complete set of data. In other words, each block is generated on the basis of the previous block data, which ensures the uniqueness of the blockchain data
each blockchain database is essentially an event chain connected in chronological order, which uses the cryptographic mechanism specified in the protocol for authentication to ensure that it will not be tampered with or forged. 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.
each block is filled with transaction records, and the blocks are connected in sequence to form a chain structure, which is the blockchain ledger
blockchain technology divides the data to be stored in the database into different blocks. Taking bitcoin as an example, when miners generate new blocks, they need to calculate the new hash value and random number according to the hash value of the previous block, the new transaction block and the random number. Each block is linked to the back of the previous block through specific information, and connected in chronological order to present a complete set of data. In other words, each block is generated on the basis of the previous block data, which ensures the uniqueness of the blockchain data
each blockchain database is essentially an event chain connected in chronological order, which uses the cryptographic mechanism specified in the protocol for authentication to ensure that it will not be tampered with or forged. 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.
6. Jinwowo group, based on the blockchain model architecture, does the analysis in the following way:
1 - data layer: data block, chain structure and time stamp
2 - network layer: P2P network, propagation mechanism, verification mechanism
3 - consensus layer: pow, POS, dpos
4 - incentive layer: issuance mechanism, distribution mechanism
5 - contract layer: script code, algorithm mechanism, smart contract
6-application layer: encapsulates various application scenarios
in the future, jinwowo group will focus on promoting the legal circulation and commercial application of big data with blockchain technology.
1 - data layer: data block, chain structure and time stamp
2 - network layer: P2P network, propagation mechanism, verification mechanism
3 - consensus layer: pow, POS, dpos
4 - incentive layer: issuance mechanism, distribution mechanism
5 - contract layer: script code, algorithm mechanism, smart contract
6-application layer: encapsulates various application scenarios
in the future, jinwowo group will focus on promoting the legal circulation and commercial application of big data with blockchain technology.
7.
Hash algorithm maps any length of binary value to a fixed length of smaller binary value, which is called hash value. Hash value is a unique and compact numerical representation of a piece of data. If you hash a piece of plaintext and change only one letter of the paragraph, subsequent hashes will proce different values. It is computationally impossible to find two different inputs with the same hash value
message authentication code (MAC) hash function is usually used with digital signature to sign data, while message detection code (MDC) hash function is used for data integrity
the basic information of bitcoin network is as follows:
all digital currencies that need to be mined have hash values, such as Laite coin, Ruitai coin, doggy coin, Weimeng coin, Diandian coin, Yuanbao coin, etc< br />
8. Fool tests Summoner
[comedy + compare h bar]<
grandson of the slippery ghost
[so this is introced by a friend = v = I haven't seen it]
black cat
[male master is a killer, and he was called the terminator of hell later because he was influenced by Shaye]
holy mark of the wind
[absolutely recommended!! The handsome male protagonist is the contractor, controlling the wind is the wind warlock, while the female owner is the famous fire warlock family. Then they quarrel when they meet, but they have very good feelings. They are both arrogant. But later, another person who lives in the male owner's memory appears. The male owner of the weak and weak shrimp suddenly knows that his family has the power to become a robber. Then turn around and turn into a robber. It's very handsome
goblin's tail
[keep pushing. Magic. The painting style is beautiful, the plot is better, it's just a little hot, but you're sure to like it!]
leaves... If it's not enough, then you go to QQ, I'm telling you, I've seen animation ~ give me 0.0
[comedy + compare h bar]<
grandson of the slippery ghost
[so this is introced by a friend = v = I haven't seen it]
black cat
[male master is a killer, and he was called the terminator of hell later because he was influenced by Shaye]
holy mark of the wind
[absolutely recommended!! The handsome male protagonist is the contractor, controlling the wind is the wind warlock, while the female owner is the famous fire warlock family. Then they quarrel when they meet, but they have very good feelings. They are both arrogant. But later, another person who lives in the male owner's memory appears. The male owner of the weak and weak shrimp suddenly knows that his family has the power to become a robber. Then turn around and turn into a robber. It's very handsome
goblin's tail
[keep pushing. Magic. The painting style is beautiful, the plot is better, it's just a little hot, but you're sure to like it!]
leaves... If it's not enough, then you go to QQ, I'm telling you, I've seen animation ~ give me 0.0
9. It's easy to trade legal money and then buy and sell it. Bloex can buy half price bitcoin.
10. The old monk took eight disciples
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