As such, the verification is reliable as long as honest nodes control the network, but is more vulnerable if the network is overpowered by an attacker. While network nodes can verify transactions for themselves, the simplified method can be fooled by an attacker's fabricated transactions for as long as the attacker can continue to overpower the network.One strategy to protect against this would be to accept alerts from network nodes when they detect an invalid block, [...]
"simplified method"
The quote refers to the SPV clients, while instead we are talking about full nodes verification.
The text is also talking about full nodes. I've re-bolded to help you out. As it nodes, an attacker might overpower the network with invalid blocks (this is not possible in the BU security model, because having more hashpower is the
definition of "valid" there, and it states that this is prevented by network nodes because they validate, but in BU the network nodes trust miners instead of enforcing on their own.
There is also a big difference on "trusting the miners" and "trusting the legit miners". BU nodes trust the legit miners.
Where is the difference? Legit BU miners aren't going to blindly accept blocks bigger then their EB settings.
Because this damaging the users and belief in the Bitcoin system will damage their income.
So, the possible attacker (from the quote of the bitcoin.pdf you have reported) will just mine huge blocks that will go nowhere.
BU nodes instead (with the current default setting, that the user can freely change) aren't going to accept bigger block without 12 consecutive blocks after it. (AD setting)
If the attacker is overpowering the network, as noted, they can produce any number of blocks ahead on their chain. Not just 12.
No: more work wins, all that change does is potentially influence the behavior on ties of equal work (and potentially enable new selfish mining strategies, while slowing down validation and making it more memory hungry). Meaning an overpowering attacker can do whatever they want. This is the BU model and it is unlike the model described in the Bitcoin whitepaper or implemented in any version of the software ever released.