What Is ‘Block Propagation’ and Why Is Its Speed Important for Network Security?

Block propagation is the process of distributing a newly mined block across the entire network of nodes. Its speed is crucial for network security because fast propagation minimizes the time window during which miners can be working on different chains, thus reducing the probability of accidental forks and stale blocks.

Slower propagation increases the vulnerability to attacks like selfish mining, as it gives attackers more time to execute their block-withholding strategy.