The idea in the link is so stupid . It acts under the assumption that the rejecting 49 % is powerless . We ' ll simply write in a little code to reject blocks that look like thisHash normal core header , with BU ' s version tag . Include only TWO transactions coinbase and special transaction which contains BU ' s blockheader data . There will then be two or three chains . That ' s the easiest way to block an attack like this . But I suspect there are better . It ' s funny to think that this is what you have been clamoring about for a few days . <| sep |> I know what you mean . They failed me first time on my driving test in Coleraine because I apparently didn ' t look at the oncoming traffic on the way back to the test centre .