Bitcoin transaction confirmation

1. You are right. Indeed, it will be rolled back. If the transaction is unfortunately packaged on the fork, the transaction is likely to be cancelled after the main chain is synchronized

the reason why we need six confirmations is that it is more difficult to obtain the optimal solution (to prevent single node fraud). One block may also be able to get an optimal solution, and it is basically impossible to get six blocks together. It has nothing to do with bifurcation

2. 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
anyone can become a bitcoin miner by running software on specialized hardware. mining software monitors transaction broadcast through P2P network and performs appropriate tasks to process and confirm these transactions. Bitcoin miners can earn transaction fees paid by users to speed up transaction processing and additional bitcoin issued according to fixed formula

new transactions need to be included in a block with mathematical workload proof before they can be confirmed. This kind of proof is hard to generate because it can only be generated by trying billions of calculations per second. Miners need to run these calculations before their blocks are accepted and rewarded. As more people start mining, the difficulty of finding effective blocks will be automatically increased by the network to ensure that the average time to find a block remains at 10 minutes. Therefore, the competition for mining is very fierce, and no indivial miner can control the content contained in the block chain
workload proof is also designed to rely on previous blocks, which forces the time sequence of block chain. This design makes it extremely difficult to cancel previous transactions, because the workload proof of all subsequent blocks needs to be recalculated. When two blocks are found at the same time, the miner will process the first block received, and once the next block is found, it will be transferred to the longest block chain. This ensures that the mining process maintains a global consistency based on processing capacity
bitcoin miners can neither increase their rewards by cheating, nor deal with the fraulent transactions that destroy the bitcoin network, because all bitcoin nodes will reject the blocks containing invalid data that violate the bitcoin protocol rules. Therefore, even if not all bitcoin miners can be trusted, the bitcoin network is still secure
if you still don't understand, go to bitcoin home to see the deeper understanding of netizens.

3. If you want to ensure the irreversibility of the transaction, you have to wait for six data blocks to be fully confirmed, which takes at least one hour to confirm.

4.

Transaction mode of bitcoin

bitcoin is e-cash similar to e-mail, and both parties need "bitcoin wallet" similar to e-mail and "bitcoin address" similar to e-mail address. Just like sending and receiving e-mail, the remitter pays bitcoin directly to the other party through a computer or smart phone according to the recipient's address. The following table lists some websites that download bitcoin wallets and addresses for free

a bitcoin address is a string of about 33 characters long, consisting of letters and numbers, always starting with 1 or 3, such as & quot& quot; Bitcoin software can generate address automatically, and it doesn't need to exchange information online, so it can be offline. More than 2 bitcoin addresses are available. Figuratively speaking, there are about two grains of sand in the world. If there is an earth in each grain of sand, then the total number of bitcoin addresses far exceeds the number of all the sand on all these "earths"

the bitcoin address and private key appear in pairs, and their relationship is just like the bank card number and password. A bitcoin address is like a bank card number, which records how much bitcoin you have on it. You can generate bitcoin address at will to store bitcoin. When each bitcoin address is generated, a corresponding private key of the address will be generated. This private key proves that you have ownership of the bitcoin at that address. We can simply understand the bitcoin address as the bank card number, and the private key of the address as the password of the corresponding bank card number. Only when you know the bank password can you use the money on the bank card number. Therefore, please keep your address and private key when using bitcoin wallet

after the transaction data of bitcoin is packaged into a "data block" or "block", the transaction is initially confirmed. When a block is linked to a previous block, the transaction is further confirmed. After six block confirmations in a row, the transaction was irreversibly confirmed. Bitcoin P2P stores all transaction history in a "blockchain.". The blockchain continues to extend, and once new blocks are added to the blockchain, they will not be removed. Blockchain is actually a distributed database composed of a group of scattered client nodes and all participants, which is a record of all bitcoin transaction history. Nakamoto predicts that when the amount of data increases, users hope that not all the data will be stored in their own nodes. In order to achieve this goal, he uses the hash function mechanism. In this way, the client will be able to automatically eliminate those parts that it will never use, such as some very early bitcoin transactions

5. No, the transaction that belongs to you, that is, your utxo will be saved to your bitcoin wallet file, and each payment will be found from your wallet database. If you lose the contents of your wallet, you can use your key information to access the service node to retrieve your utxo. If you lose the key, don't worry.

6. After bitcoin transaction data is packaged into a "data block" or "block", the transaction is initially confirmed. When a block is linked to a previous block, the transaction is further confirmed. After six block confirmations in a row, the transaction was irreversibly confirmed. Bitcoin P2P stores all transaction history in a "blockchain.". The blockchain continues to extend, and once new blocks are added to the blockchain, they will not be removed< br /> 
when we submit a transaction, under normal circumstances, the transaction will eventually be put into a certain block by miners. At this time, we can say that the transaction has obtained 0 confirmations. When there is another blockchain to this exchange in the block, that is, when this exchange in the block is the parent block, we say that this transaction has been confirmed, and so on. How many confirmations a transaction has obtained is just how many blocks the exchange links behind the block.

7. 1. Attack the dark prince
The Greenwood gang has no range damage, while the dark prince has range damage. The combination of the two is a bit like the combination of giant and dark prince. The combination of Greenwood gang and black king has both flesh and high damage. The dark prince can still bear the fat man when he rushes up. Xiaobian thinks that after the official launch of the Greenwood Gang, there should be a wave of double king Greenwood Gang sets (look at the current double king giant sets)
2, attack well, Jiyou mortar
Greenwood gang has a good defensive role, with dirty crossbow, dirty gun effect is very good. When our side releases the mortar, the other side will issue the card to attack our mortar, and then release the Greenwood Gang: Greenwood brother can absorb damage, Greenwood sister can output madly (provided the other side has no rolling wood ~)

3, attack the skeleton balloon of good friends
because the Greenwood gang and the skeleton balloon are afraid of rolling wood, they will play the two cards together. The other party may put rolling wood in front of the princess tower when the Greenwood younger sister attacks. At this time, the Greenwood younger brother + skeleton balloon can attack near the tower; Or when the skeleton balloon falls to the ground, put the rolling wood. At this time, the little sister of Greenwood can hit the princess tower a few times first. Pay attention to the skull balloon placed behind Greenwood, so as to increase the difficulty of the opponent under the rolling wood
4, attack the three musketeers of good Jiyou

brother Greenwood is a fat man. When he uses three guns, he can keep up with the Greenwood gang. The other way is with a low-cost Iceman. Pay attention to Greenwood Gang 5 fees, it is best to double the holy water when such a card
5, good attack base friend balloon soldiers
Greenwood gang with balloon soldiers is also very good. Brother Greenwood is fighting blood in front. Sister Greenwood can protect the balloon and destroy the other air force. As shown in the picture, the Greenwood girl will kill the flies in the air
6, attack good base friend digger

when the Greenwood Gang is released, you can attack with the miners, so there will be two flesh shield Greenwood brothers and digger to fight blood. Note that when Greenwood brother pulls the princess tower to hate, it's best for the miner to land again
7, attack the good base friends and the wild woodcutter
after the green forest Gang officially launched, there should be more people with rolling wood. If the other party annihilates Greenwood younger sister, how to maximize Greenwood younger brother's output? The wild woodcutter should be a good choice, meat + fast running, fast output of the wild woodcutter
8, how to place the Greenwood Gang
let's talk about how to place the Greenwood gang in defense. Put our buildings and Greenwood gangs separately (on the right side of the figure below), so as to avoid being hit at the same time when the other party drops the fireball. Other cards such as Musketeers and archers should be placed separately from our buildings
9, if the other side releases the rolling wood, we might as well follow a goblin gang.
if the other side releases the rolling wood to roll our Greenwood younger sister, we might as well follow a goblin gang. The combination of goblin gang and Greenwood younger brother will also have good output (unless the other side takes ten thousand arrows at once + rolling wood / mirror image + rolling wood double spell)
10, be careful to go down the Greenwood Gang + goblin flying bucket at the same time
Greenwood girl and goblin flying bucket are afraid of rolling wood. If the other party has rolling wood, they should not go down at the same time
11, the Greenwood gang can defend two of the three guns
5-fee Greenwood gang can defend 6-fee double gun
12, shunting

8. Illegal
at present, there is no recognition that any virtual currency is legal in China, including bitcoin, which was very noisy a few years ago. In the end, the central bank directly declared it illegal.

9.

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