its 10 minutes for each verification. A transaction is fully confirmed(that is, without possibility of fraud) in the 6th confirmation(this is why 6 confirmations is the magic number).
In what way does the 6th confirmation make it "without possibility of fraud"? Why isn't is "without possibility of fraud" after 5 confirmations?
The point I'm trying to make is that many people seem to imbue the number 6 with some magical power that makes it impossible to reverse.
In order to "reverse" a confirmed transaction, you have to create blocks faster than the rest of the honest network. This requires a hugh amount of hash power. If you have enough hash power to reliably reverse a transaction that has 5 confirmations, then you have a really good chance of reversing a transaction that has 6 confirmations too.
Once you have 1 confirmation, it becomes extremely difficult to reverse the transaction unless a very large mining pool is assisting you in your attempt at fraud. Each additional confirmation makes it significantly more difficult to "reverse" the confirmed transaction (even with the help of a very large mining pool).
So:
5 confirmations requires more luck and more hashing power than 4 confirmations.
6 confirmations requires more luck and more hashing power than 5 confirmations.
7 confirmations requires more luck and more hashing power than 6 confirmations.
Each business needs to decide for themselves how much risk they are willing to accept, and at what cost.
Choosing "6 confirmations" as some sort of "magic number" that makes the transaction irreversible is a fantasy. In the extreme majority of cases, most businesses will be just fine accepting 1 or 2 confirmations. In many cases, a business can accept 0 confirmations (in other words, they can accept the transaction immediately after it is sent) without any increase in risk beyond the risks they are already accepting by operating the business.
