ttacker’s ASICs useless, but the second time you no longer have that option, and so the attacker can attack again and again.…ve power incentivized into existence by massive rewards. Recovery from attacks in PoW is very hard: the first time it happens, you can hard fork to change the PoW and thereby render the attacker’s ASICs useless, but the second time you no longer have that option, and so the attacker can attack again and again. Hence, the size of the mining network has to be so …
