you misunderstood, i said that is the problem that it's not energy based, because ultimately, everything is based on energy. all permissionless-consensus-critical crypto-systems that do not understand this only boil down to an inelegant or obscure form of proof-of-work at the end of the day again. "nothing is cheaper than proof-of-work": http://www.truthcoin.info/blog/pow-cheapest/