Since GENESIS_BLOCK_ID = 2680262203532249785L is hardcoded in Genesis.java, I don't see how the attacker could succeed. All he could do is create a Nxt clone.
Yes I see. Thanks. In effect, the 'bootstrap number' I've been talking about, is now 'PART OF THE PROTOCOL'.
Although - if the initial stake holders ever sold their private keys once those accounts were empty, or lost / hacked / QC cracked, then maybe you could cause a little heart ache..
True. But it would be a lot of work for an attacker to get these historical keys, create a new chain that seemed to have a greater cumulative difficulty, fake all the timestamps and rolling checkpoints, and then they'll only fool newcomers to the Nxt blockchain with no one to tell them which is the correct one.
By the time someone attempts such at attack, there may be other protections in place. I know that Consensus Research are looking into options.