- block peers for 24hs if they transmit a block that is building on an old block, i.e., active_chain.height - small_chain.height > 4 (6? …), and reject the block.
The problem is that they can continue working on the small chain, and it can eventually become the longest chain. Then there would be a fork, because new nodes would follow the longest chain.
One thing to minimize this problem is to determine which chain to follow based on the chain >= 70% of their peers are following. Ideally it should first establish connection with at least 8 peers.
Unlucky new nodes could be victim of sybil attacks, but I think it would happen very rarely.
The most important thing is that it would undermine selfish mining, or at least make the attackers think twice, because they would be using a lot of resources to create a chain that the majority of the network would not be accepting.
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yes this would be shifting the longest chain to trust on nodes. It could possibly create many forks …
