Long Range Attacks

PoH provides a natural defense against long range attacks. Recovering the ledger from any point in the past would require the attacker to overtake the valid ledger in time by outpacing the speed of the PoH generator. The consensus protocol provides a second layer of defense, as any attack would have to take longer then the time it takes to unstake all the valid validators. It also creates an availability gap in the history of the ledger. When comparing two ledgers of the same height, the one with the smallest maximum partition can be objectively considered as valid.