Anti-transaction replay in a hardfork

Edmund Edgar agreed with the general point but said that it was possible to do anti-replay without prior knowledge of the fork. He suggested allowing transactions to specify a recent block hash and declaring them invalid if that block isn't in the parent chain. This would be beneficial beyond economic hard-fork situations. Edmund Edgar is the founder of Social Minds Inc and can be found on Twitter, LinkedIn, and Skype. He is also associated with Reality Keys at realitykeys.com.