Number of unconfirmed transactions in bitcoin

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.

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

4. Radar coin will, bitcoin did not encounter this situation!

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. The worst thing is not to transfer bitcoin directly from one trading platform to another, because some platforms do not support this transfer method. It is better to withdraw bitcoin from one trading platform to the wallet, and then transfer the coin in the wallet to another trading platform
in this case, it's better to consult the customer service staff of the platform. Similar situations may be encountered with counterfeit coins such as Wright coin, Ruitai coin and dog coin.

7. Go to the bitcoin blockchain website to query the transaction data on the chain

8. When you initiate a transfer, how does bitcoin get to the payee
when you initiate a bitcoin transfer, you need to broadcast the transaction to the whole network. After receiving the transaction, the mining node first puts it into the local memory pool for some basic verification, such as whether the bitcoin spent in the transaction is not spent
if the verification is successful, it will be put into the "unconfirmed transaction" and wait to be packaged; If the validation fails, the transaction will be marked as "invalid transaction" and will not be packaged. That is to say, mining nodes need to verify each transaction and update their own "unconfirmed transaction pool" while competing for computing power. After the node grabs the bookkeeping right, it will extract about 1000 "unconfirmed transactions" from the "unconfirmed transaction pool" for packaging
sometimes our transactions can't be packaged in time because there are too many transactions in the "unconfirmed transaction pool", and the number of transactions that can be recorded in each block is limited, which will cause block congestion.

9. 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.