Question :A bitcoin transaction with 6 confirmations is usually considered to be secure. Why is it so?
I have 2 previous answers to update, I'll try my best to update it within 48-72 hours along with the answers for this question.
As mentioned in
bitcoin wiki, only 6 blocks or 1 hour is enough to make reversal computationally impractical. Generally when it reaches 6 confirmations, there will be far less possibility for the transaction to be reversed, thus it is secure. 10 minutes is the average time needed to find a block. It will be very very hard for attacker to overtake the blockchain from a fork six blocks prior.
Also, in Satoshi's paper (
https://bitcoin.org/bitcoin.pdf), it shows:
P < 0.001
q=0.10 z=5
q=0.15 z=8
q=0.20 z=11
q=0.25 z=15
q=0.30 z=24
q=0.35 z=41
q=0.40 z=89
q=0.45 z=340
If the attacker has a small percentage of hashing power then 6 blocks will be enough to ensure the secure of the transaction.
Show Posts
