Hi everybody,
I am trying to get deeper into the understanding of bitcoins, but there are still a few things unclear.
So If we all mine bitcoins, then what we do is just to find a hash, that matches a specific criteria.
If this hash is found, then a new block is found and (currently) rewarded with 25 BTC.
But how can this happen exactly every 10 min? How can this be timed so accurately?
If I compare this with password bruteforcing, I have no estimate about the time, I will find a correct hash?
It does not happen exactly every 10 minutes, as was said above if you look at the actual block times they vary by quite a bit. Sometimes you get two blocks within a minute, and sometimes it takes over an hour to get a block, but the average is 10 minutes.
Think of it like if you roll dice, if you roll a 6 sided die once a second you would expect to get a 1 about every 6 seconds. But sometimes you would roll a 1 two times in a row, and sometimes you would roll a bunch of other numbers, but on average the 1 would come up about every 6 seconds.
If more people start mining bitcoins then the blocks will start coming faster. Like in my die rolling example, if you start rolling two dice then you will get a 1 twice as often. But what happens is the bitcoin protocol adjusts the difficulty every so often (about every two weeks, but actually there is a set number of blocks which it recalculates at). So in our dice example, after rolling two dice for a while you get changed to 12 sided dice, so then the rate of finding 1's goes back to where it was before.
The difference between this and brute forcing a password is that there are more possible answers for this (any number less than difficulty, as opposed to just one right answer). You could make an estimation of the time it takes to do a brute force, but since you are just looking for one answer the probable time is less meaningful, people usually state the time needed to try all possible passwords. So if your brute force can run through all possible passwords in 10 days, the average time to find the password would be 5 days, but you might find it in the fist day or you might find it in the last day.