Why do keep fixating on "longest chain"? ? ?
The longest chain does not determine the accepted chain. With no disrespect intended it is clear that you do not even have a basic fundamental understanding of 51% attacks or any other for that matter. Everything proposed as "protection" in this thread is flawed to say the least.
~BCX~
Correct me if I am wrong, but the longest valid chain is the accepted chain no?
No if it's behind the last checkpoint for instance.
Yes, but checkpoints don't affect this system(other than the hard checkpoints we manually put in), as the auto-checkpointing is done locally and only stored in memory, it is lost upon closing the client.
That's what I'd like you to explain in depth including why you think it's better than ACP which is a proven solution.
I have modified my post accordingly,
By ACP, I assume you mean feathercoin's solution, I've not read that much about it in detail however from what I know
ACP may be "proven" but its still centralized... all one has to do is take down the checkpoint server(s) and then proceed with the attack.
This is a decentralized defense system that does the same job, arguably better for certain kinds of attacks.