Some individuals have expressed the opinion {that a} profitable double-spend assault would invalidate Bitcoin as a expertise, and thus undermine the worth of all Bitcoins (together with the attacker’s), making an assault an unwinnable scenario.
The “assault undermines the community” assumption is usually used to justify why a rational actor would by no means try an assault.
Bitcoin, being a public ledger, makes it very simple to detect if somebody carried out a double spend assault. And we might know based mostly on the size of the re-org whether or not or not the attacker had over 50% of the hashpower (per the whitepaper, a >=6 block re-org signifies a 51% assault with excessive certainty.)
My thought is that if my node detected a big re-org and double spend inside that re-org, I might not settle for cost related to the double spender. If his id was publicly identified, no one would settle for his Bitcoins as a result of they know they’re liable to be double spent. If his id was not publicly identified, his Bitcoins are nonetheless tied to the assault, and no one ought to just accept them for a similar cause.
However on the opposite facet of the coin… Now, I do know for a truth that each one different Bitcoins not related to the attacker can not be double-spent, as a result of by definition just one entity can have greater than 50% of the hash energy at a given time. I can really settle for Bitcoins from everybody apart from the attacker with an excellent larger stage of confidence than I might earlier than!
Would this create a scenario the place the attacker has successfully burnt his personal cash whereas concurrently growing the trustworthiness of all different cash?
Or mentioned one other method: is it legitimate that we shouldn’t have to imagine a 51% assault would undermine your entire community’s worth to conclude that it could nonetheless be self-undermining for the attacker?