If you've been using Bitcoin to transfer money recently, you may realize that waiting for confirmation is so long that it's not suitable for use as a currency. If you want your transaction to be included in the next block, you'll have to wait for this A transaction is confirmed on the blockchain 1-6 times. The waiting time varies from 10 minutes to 60 minutes. Bitcoin's transaction design was not originally like this. Before 2015, most Bitcoin transactions were instant. This feature is called 0 confirmation means 0 confirmation transaction At that time, it was much more convenient to use Bitcoin as a payment method than it is now. You only need to scan your mobile phone and your transaction will be broadcast to the network and then it’s done. You don’t need to wait for multiple confirmations There is no need to worry about whether your transaction will be packaged into the next block.
At that time, unconfirmed transactions can be trusted because the first broadcast transaction will be packaged into the next block. If someone tries to initiate a A double-spend transaction means sending the same amount of money to a second address without confirmation. The second transaction will be ignored by the network. In this way, since the ability to double-spend or cancel the transaction is lost, the merchant can safely assume that this Transactions are guaranteed to be confirmed in the next block and you don't have to wait for instant transactions. It would have been very reliable until the Bitcoin Core team decided to introduce a so-called fee market strategy to keep blocks small and fees to rise to what users are willing to pay for security The upper limit of fees increases with transaction fees and blocks full.
If your transaction fees are low, your transactions may be stuck in the mempool for weeks. To solve this problem, Bitcoin core has added a new feature. ——Replace-By-Fee (RBF) This function says that the original intention of allowing you to double-spend your own transaction RBF is that when your transaction is stuck in the memory pool due to insufficient handling fees, you can pay a higher fee to rebroadcast the transaction (replacing the original one) This increases the probability that the transaction will be included in the next block. Unfortunately this practice destroys 0 confirmations with RBF when you use bits After you buy an item with coins, you can leave the store and rebroadcast a transaction with a higher fee to transfer the money back to your own address.
This way you get the money back after deducting the miner fee. This forces the merchant to only Being able to trust transactions that have been confirmed by the blockchain is the reason we have long wait times today Bigger trouble for people who want to use Bitcoin as a currency, the Bitcoin community is divided, and those who want to use Bitcoin as a currency initiate a hard fork (BCH) The BCH fork removes RBF and increases the block size so that 0 confirmations are still available Normal use Currently 0 confirmation is still the most reliable and proven way of instant transactions on decentralized blockchains but It is like most things in the cryptocurrency system.
In theory, as long as you use enough resources, you can still find possible attack methods. Technically, even if you remove RBF, it is still possible to double spend a transaction. If you buy The problem is that most of this type of double-spending transactions are not worth the loss (it is difficult for attackers to profit from it) Even so, you are on the BCH chain Most of the 0-confirmation transactions made are still very safe, but if you are selling a Lamborghini or a mansion to a cryptocurrency mogul, you should wait for a few confirmations..
