-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 As you all know keeping the size of the UTXO set small is critical, and more recently we've also had problems with distasteful data being added to the UTXO set. (http://garzikrants.blogspot.se/2013_04_01_archive.html) Gregory Maxwell has an excellent solution to the distasteful data problem in the form of P2SH^2 (http://comments.gmane.org/gmane.comp.bitcoin.devel/1996) and Peter Todd pointed out how we can implement it with the existing P2SH form. We're also going to be implementing some kind of OP_RETURN <data> soon which handles the timestamping and similar use-cases, again without UTXO impact.
Right now the only scriptPubKey form with any significant use is the checksighash. Bare pubkey gets used by the odd miner, and by Deepbit due to their ancient codebase. The former isn't an issue as the miner mines the txout themselves, and the latter shouldn't find updating to be a big deal. OP_CHECKMULTISIG is used by Peter Todd's timestamper, but that can be changed to OP_RETURN without difficulty. However all that will (hopefully!) soon change as hardware wallets and the payment protocol make hardware wallets worthwhile, and we should make sure these protocols take the extra step of using P2SH before we get locked into a bunch OP_CHECKMULTISIG implementations. We also have the problem that the IsStandard() code accepts up to 120 bytes of junk data as a pubkey, allowing injection of 240 bytes of *spendable* data into the UTXO set with bare OP_CHECKMULTISIG. This capability has to be stopped. Thus I'm offering a reward of 1BTC for whomever creates a patch to change IsStandard() to accept only P2SH and pubkeyhash in a raw scriptSig, allowing other forms only when used with P2SH. I'm offering a further 1BTC to whomever gets such a patch accepted into mainline. It's a pretty easy patch, so I'm asking that all core-developers (that includes you Peter) hold off for one week to give less experienced developers a crack at it. If for some reason you want to remain anonymous that is ok by me as well provided you assign copyright to me. I do expect unittests. Should be about half a day to a days work. Long-term we should be using P2SH with an inner OP_CHECKSIG for most addresses as it's a 1 byte savings. Change addresses can have this done first, although bitcoinj support will help so that satoshidice and similar sites can pay to P2SH change. As for multisig's P2SH overhead for a 1-of-2 and 2-of-2 and 3-of-3, is 10%, 8.6% and 6.2% respectively, all pretty minor, especially if you assume the blocksize limit will be raised. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAEBCAAGBQJR4vX+AAoJEEWCsU4mNhiPg/EIAKWFaMsugbY4zZ+dpgnaTcUr D1ZnY5PogETVqcwuXdVdHe2zCUcBhejsBe8ic9vp8OnttXTxo8uXJp9xBuq9VYBN vXMyGKtxacLL5WS5ShAWnWS47xLf9wnKCJSGX0nqaETIQEUgqCMjTGspZNOpC9W0 fKBIDi4cZbpXn1EQx45v9vplZhFg+vBQV/Ia2/5rjZLPFvdqZoSBruOVTB/X2SDU Hq36DQkRFblp/s3Ktv9c3yUQ8HocRIXD8jKRsE+uCNfEeI2b9oLpPp1cPsOvjveI McJnHod8EDzxwbm6abK2cxHWBpGmBa5AABsRmQfpJK+u7GDQoPqzfJ68M1otZjk= =uP4n -----END PGP SIGNATURE----- ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
