Could an attack such as a 51% attack succeed in eradicating bitcoin (erasing all or "recent" transactions)? Could it be done anonymously? And again, most importantly, is there any solution to this within the bitcoin framework or in a proposed cryptocurrency. For example what if the blockchain of a new cryptocurrency were hosted only through servers in safe countries run by vetted individuals? What if the coins were not mined but donated at a given rate to a basket of legal protection & PR entities while the trusted servers ran off transaction fees? Is anything being considered or constructed as a backup in case bitcoin is taken down by a 51% attack - is there a consensus solution? Because if there is no backup or solution it makes such an attack far more likely.
Yes a >50% (it isn't 51% btw) can erase all transactions since it forks (the miner can just mine empty blocks) and if that miner keeps winning then the blockchain could be rendered effectively useless as no tx would ever confirm (whilst it is still building the longest chain).
This problem has been discussed before but no solution has yet been proposed other than some sort of manual control (i.e. centralised decision) to be made by the devs.
I would certainly like to see a better method to prevent "unwinding back to the last check point" but seemingly no good (or agreed) method has been proposed.