That opcode would not help as it fetches block hash and not the content of the header. > On May 23, 2019, at 21:05, Nathan Cook wrote: > > You can get the same effect with OP_CHECKBLOCKATHEIGHT as proposed by Luke Dashjr (https://github.com/luke-jr/bips/blob/bip-cbah/bip-cbah.mediawiki ) if you also re-enable/extend certain opcodes like OP_AND and OP_LESSTHAN. See https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2016-September/013149.html and the ensuing thread. > > Nathan Cook > > > On Thu, 23 May 2019 at 21:33, Tamas Blummer via bitcoin-dev > wrote: > Difficulty change has profound impact on miner’s production thereby introduce the biggest risk while considering an investment. > Commodity markets offer futures and options to hedge risks on traditional trading venues. Some might soon list difficulty futures. > > I think we could do much better than them natively within Bitcoin. > > A better solution could be a transaction that uses nLocktime denominated in block height, such that it is valid after the difficulty adjusted block in the future. > A new OP_DIFFICULTY opcode would put onto stack the value of difficulty for the block the transaction is included into. > The output script may then decide comparing that value with a strike which key can spend it. > The input of the transaction would be a multi-sig escrow of those who entered the bet. > The winner would broadcast. > > Once signed by both the transaction would not carry any counterparty risk and would not need an oracle to settle according to the bet. > > I plan to draft a BIP for this as I think this opcode would serve significant economic interest of Bitcoin economy, and is compatible with Bitcoin’s aim not to introduce 3rd party to do so. > > Do you see a fault in this proposal or want to contribute? > > Tamas Blummer > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev