It's true that it fetches the block hash; the idea is to compare the block hash's numeric value to the desired (uncompressed) difficulty directly, using a 256-bit version of OP_LESSTHAN. Nathan Cook On Thu, 23 May 2019 at 22:18, Tamas Blummer wrote: > 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 < > bitcoin-dev@lists.linuxfoundation.org> 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 >> > >