I see, means that for the others what an attacker can do is:
- Prevent some or all transactions from gaining any confirmations
- Prevent some or all other miners from mining any valid blocks
If the attacker prevents transactions from gaining confirmations, what does this mean exactly? Lets say if I send 25 BTC and an attack comes up at that moment, means that neither me or the receiver will effectivly hold the coins? (while the attack takes places...?) and when the attack is over all would be back to normal are is there possibility of irreversible damage?
Your wallet reduces your balance for convenience but although we say "sending" transactions are never in transit. A transaction signs over "ownership" to the receiver's key. Either the tx confirms at which point the receiver has the "coins" or it doesn't and you still do. There is never a single millisecond where no party controls the coins and a denial attack doesn't change that.
That being said a denial attack
would damage Bitcoin. It may not do any damage at the protocol level, coins couldn't be erased. It would however undermine confidence in the system, potentially fatally. Imagine tomorrow no Bitcoin transactions could be confirmed and it was 60 days before the attack was defeated and tx could start being confirmed again. What do you think would happen to user base, confidence, merchant adoption, exchange rate, etc?
