Bitcoin broadcasting
Publish: 2021-04-08 16:21:15
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. The reason why blockchain ledger can be decentralized is that all nodes of the network synchronize the ledger with each other and keep consistent. Therefore, blockchain does not need a centralized bookkeeping institution, so what is the node
bitcoin is a kind of point-to-point e-cash system, more directly, node to node. Each transaction is broadcast by the originator to the nodes around it, and then broadcast to the nodes around it after receiving it, and finally spread to the whole network
every bitcoin wallet is a node, and the node with a complete blockchain ledger is called the whole node. In October 2017, there were about 9300 nodes in the bitcoin network, which were responsible for broadcasting and verifying bitcoin transfer transactions. After the transfer transaction occurs, all nodes broadcast to the whole network. After the mining node verifies that the transaction is correct, it will be recorded in the blockchain ledger. The United States, Germany and France have the largest number of bitcoin nodes, with China accounting for about 5% of the world's total nodes Data source: bitcodes. 21. CO) running bitcoin node does not provide any reward, and it does not need the whole node to transfer bitcoin, so the total number of bitcoin nodes only accounts for a small part of the node number.
bitcoin is a kind of point-to-point e-cash system, more directly, node to node. Each transaction is broadcast by the originator to the nodes around it, and then broadcast to the nodes around it after receiving it, and finally spread to the whole network
every bitcoin wallet is a node, and the node with a complete blockchain ledger is called the whole node. In October 2017, there were about 9300 nodes in the bitcoin network, which were responsible for broadcasting and verifying bitcoin transfer transactions. After the transfer transaction occurs, all nodes broadcast to the whole network. After the mining node verifies that the transaction is correct, it will be recorded in the blockchain ledger. The United States, Germany and France have the largest number of bitcoin nodes, with China accounting for about 5% of the world's total nodes Data source: bitcodes. 21. CO) running bitcoin node does not provide any reward, and it does not need the whole node to transfer bitcoin, so the total number of bitcoin nodes only accounts for a small part of the node number.
3. You have too many questions... It's hard to answer. I picked a few answers
what is the essence of bitcoin
A: in essence, it is a multi person account book. But the currency (bitcoin) on the account book is generated out of thin air, and the algorithm is sha256 workload proof
how to identify its uniqueness< As like as two peas, br / > answer: it's still a book. All the books are kept by all the game player in the world. Just imagine, the whole world knows that I have five coins. I pay five coins to a in the way of bookkeeping, and keep the account book. Unless you change 51% of everyone's account book, it will be effective, but the change has to be proved by workload, so it is not so easy to change. This guarantees uniqueness I can only give you a general idea. Although it's not easy to understand, you can check it yourself)
according to my understanding, bitcoin should not be stored in a database to record users' bitcoin... It is stored locally
A: it's stored locally, but it's broadcast immediately in P2P mode. Everyone who plays bitcoin keeps a locally. If your account book is different from others, for example, if you say you have 100 million, your account book is invalid. If no one admits it, it can't be sent
PS: it's learned a lot, involving economics, cryptography, sociology, computer programming, etc. One can't master all of them, so there are many people who don't understand them. When you understand 1 / 2 of what XX learned above, you will understand.
what is the essence of bitcoin
A: in essence, it is a multi person account book. But the currency (bitcoin) on the account book is generated out of thin air, and the algorithm is sha256 workload proof
how to identify its uniqueness< As like as two peas, br / > answer: it's still a book. All the books are kept by all the game player in the world. Just imagine, the whole world knows that I have five coins. I pay five coins to a in the way of bookkeeping, and keep the account book. Unless you change 51% of everyone's account book, it will be effective, but the change has to be proved by workload, so it is not so easy to change. This guarantees uniqueness I can only give you a general idea. Although it's not easy to understand, you can check it yourself)
according to my understanding, bitcoin should not be stored in a database to record users' bitcoin... It is stored locally
A: it's stored locally, but it's broadcast immediately in P2P mode. Everyone who plays bitcoin keeps a locally. If your account book is different from others, for example, if you say you have 100 million, your account book is invalid. If no one admits it, it can't be sent
PS: it's learned a lot, involving economics, cryptography, sociology, computer programming, etc. One can't master all of them, so there are many people who don't understand them. When you understand 1 / 2 of what XX learned above, you will understand.
4. You can negotiate with each other and use it in turn!
5.
blockchain has rich application scenarios
blockchain is essentially a decentralized database, which is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain can solve the problem of information asymmetry and realize the cooperative trust and concerted action among multiple agents, which has a wide range of application scenarios
-- for more data, please refer to the analysis report on market prospect and investment strategic planning of China's blockchain instry issued by foresight Instry Research Institute
6. Bitcoin receives payments almost instantaneously. However, there is an average delay of 10 minutes before the network starts adding your transaction to a block to confirm the transaction and that you can use the received bitcoin. Confirmation means that there is a consensus on the Internet that the bitcoin you receive is not used to pay others, so it is recognized as your property. Once your transaction is included in one block, all subsequent blocks will include it, which will greatly consolidate this consensus and rece the risk of transaction cancellation. Each user can determine the time when the transaction is confirmed, but generally speaking, receiving six confirmations is as safe as waiting six months after a credit card transaction
only full node clients like bitcoin core need longer synchronization time. Technically, synchronization is a process of downloading and verifying all previous bitcoin transactions on the network. Some bitcoin clients need to know all previous transactions to calculate the available balance of your bitcoin wallet and complete new transactions. This step consumes a lot of resources and needs enough bandwidth and space to store the whole block chain. In order to maintain the security of bitcoin, enough users need to use the full node client, because they play the role of confirmation and relay transactions.
only full node clients like bitcoin core need longer synchronization time. Technically, synchronization is a process of downloading and verifying all previous bitcoin transactions on the network. Some bitcoin clients need to know all previous transactions to calculate the available balance of your bitcoin wallet and complete new transactions. This step consumes a lot of resources and needs enough bandwidth and space to store the whole block chain. In order to maintain the security of bitcoin, enough users need to use the full node client, because they play the role of confirmation and relay transactions.
7. First of all, bitcoin can not be regarded as currency. Second, bitcoin is a reward of incentive system. When a transaction is generated, people who broadcast to the whole network, judge the transaction and help the broadcast will get a reward (bitcoin)
8.
Two statements for reference are found from Babbitt:
-
bitcoin adopts a mathematical contest to determine the time when a transaction arrives at a node, and at the same time to protect this order. In bitcoin system, transactions are sorted by group allocation, Such groups are called blocks (transactions occurring at the same time will be divided into the same block), and then these blocks are linked together, which is called blockchain. Blockchain is used to sort transactions, while the transaction chain tracks and records the change of bitcoin ownership. These blocks are arranged according to time, which is a link. Transactions not in the block are called unconfirmed or unsorted transactions, and any node is about to put a group of unconfirmed transactions into the block, Then broadcast their suggestions about what the next block should be to other nodes in the network
If multiple people generate blocks at the same time (the probability is very small), there will be multiple choices for the next block of the current block. In order to ensure the sequence of block links, the bitcoin system requires each effective block to include the answer to a special mathematical problem, and the computer calculates the text of the whole block, In addition, random guessing based on encrypted hash can be done until an output lower than a certain value is obtained. Hash function can create a short summary from any length of text. This fixed output value is very complex. The only way to find it is random guessing, which is called mining -
when King released PPC last year, it introced checkpoint mechanism to protect against attacks in its early development. This mechanism enables it to resist 51% attacks. " Developers can control a parent node and broadcast "checkpoints" to the whole network, which allows other nodes to agree on certain blocks“ This is actually a [blockchain] continuity warning message, "he said< br />
9. What are you broadcasting without mining
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