Why Do Replay Attacks Matter?
These assaults are particularly important to the context of bitcoin transactions and ledgers, albeit they are far from specific to it. The reason for this is that ledgers go through hard forks, which are protocol modifications or upgrades. When a hard fork occurs, the current ledger is divided into two halves, one of which runs the legacy version of the program and the other which runs the new, updated version. Some hard forks are just upgrades to the ledger, while others split off and essentially create new coins.