How does Nano protect itself from transaction flooding attacks? RaiBlocks transactions do not have fees and are processed instantly, so what protects the nodes from being flooded of tiny transactions?
From the wiki page, each transaction will be required to do around 5 seconds of Proof of Work, which will only require around 1 microsecond to validate. This means that the attacker will waste a large amount of resources while the nodes waste a very small amount.