Topic: One confirmation, two or three. When we say the transaction is safe? (Read 85 times)

Today we're going to talk about Bitcoin blockchain re-organization and then answer the question, One confirmation, two or three. When we say the transaction is safe?

All PoW chains perform a process of blockchain re-organization, whereby it sometimes happens that two blocks are mined almost simultaneously, competing at the same height so that miners see one of the blocks and assume that it is the correct block.

On average ّّّ~10 minutes later (Bitcoin Blockchain) a new block is mined. When this block is mined, we will have two blocks. Original one with a longer chain and a new, shorter block, tries to have some "orphans," which try to have new blocks on that chain.

Is this normal? Yes, it is possible to have one block re-organization every few weeks, it is the result of applying decentralization.

what happens to the transactions of the other block? Does this mean that I lost my money? we have two blocks, one is original and the other is ignored. All transactions that were included in the ignored block are returned as unconfirmed transactions awaiting confirmation.

During this process it may happen that a transaction is inserted into one of the blocks (One confirmation,) it is not a double spending.

Can two-block re-organization happen? Yes, it is possible once several years

Can three blocks re-organization happen? This process has not happened before


Is waiting for one confirmation considered safe? Well, it differs according to the value of the thing you want to pay for, so buying a house means that you have to wait for 3 confirmations and buy a daily product means that 1 confirmation is sufficient.


Question Paragraph:

Calculate the probability of two blocks being mined at the same time?
Why is the process of Bitcoin Blockchain re-organization every two weeks?
Calculate the probability that 2 blocks re-organized?
Calculate the probability that 3 blocks re-organized?