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[96.82.67.198]) by smtp.gmail.com with ESMTPSA id v62sm1839997pfv.44.2017.05.09.18.19.43 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 09 May 2017 18:19:43 -0700 (PDT) Date: Tue, 9 May 2017 18:19:30 -0700 From: Christopher Jeffrey To: Johnson Lau Message-ID: <20170510011930.GA14666@gmail.com> Mail-Followup-To: Johnson Lau , bitcoin-dev References: <20170405174343.GA7180@gmail.com> <20170509005659.GA1902@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="HcAYCG3uE/tztfnV" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.2 (2017-04-18) X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: bitcoin-dev Subject: Re: [bitcoin-dev] Extension block proposal by Jeffrey et al X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 May 2017 01:19:45 -0000 --HcAYCG3uE/tztfnV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline > To make it completely transparent to unupgraded wallets, the return outputs have to be sent to something that is non-standard today, i.e. not P2PK, P2PKH, P2SH, bare multi-sig, and (with BIP141) v0 P2WPKH and v0 P2WSH. Johnson, I feel that's not as much of an issue with v0 witness programs. Segwit isn't activated yet, and segwit-capable wallets aren't as widely deployed for production. Not to mention, they're all going to require further development anyway: the address serialization for witness programs only became a BIP this week. No segwit wallets should ever be planning to receive money to naked witness programs right now, since addresses are for it aren't even available. I think we have the benefit of timing here. The state of segwit wallet development incidentally creates a window of time where this maturity rule can be implemented. On Wed, May 10, 2017 at 01:56:28AM +0800, Johnson Lau wrote: > To make it completely transparent to unupgraded wallets, the return outputs have to be sent to something that is non-standard today, i.e. not P2PK, P2PKH, P2SH, bare multi-sig, and (with BIP141) v0 P2WPKH and v0 P2WSH. > > Mainchain segwit is particularly important here, as that allows atomic swap between the bitcoin and xbitcoin. Only services with high liquidity (exchanges, payment processors) would need to occasionally settle between the chains. > > > > On 9 May 2017, at 08:56, Christopher Jeffrey wrote: > > > > Johnson, > > > > Yeah, I do still see the issue. I think there are still some reasonable > > ways to mitigate it. > > > > I've started revising the extension block specification/code to coexist > > with mainchain segwit. I think the benefit of this is that we can > > require exiting outputs to only be witness programs. Presumably segwit > > wallets will be more likely to be aware of a new output maturity rule > > (I've opened a PR[1] which describes this in greater detail). I think > > this probably reduces the likelihood of the legacy wallet issue, > > assuming most segwit-supporting wallets would implement this rule before > > the activation of segwit. > > > > What's your opinion on whether this would have a great enough effect to > > prevent the legacy wallet issue? I think switching to witness programs > > only may be a good balance between fungibility and backward-compat, > > probably better all around than creating a whole new > > addr-type/wit-program just for exits. > > > > [1] https://github.com/tothemoon-org/extension-blocks/pull/16 > > > -- Christopher Jeffrey (JJ) CTO & Bitcoin Menace, purse.io https://github.com/chjj --HcAYCG3uE/tztfnV Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEtLH2LbrAhOMz86BKiWKrneZma70FAlkSaqIACgkQiWKrneZm a71EJAgAmeMLug09RLsRw1hpF1v9JkjS9S3s/s7SrWLmgPc8zkgOqlEGt60TMKa2 NZjV000Dbc/C1sQhX7JyxncISY5qZYcxVx+fFM1zukdd7aH0WaThSGQx4u/4gj/u Ss/mtjbjeIHe1bTWAILExEOrGRNaTfrl3v/bULAOUz3wjlEYS8HrfVf0+VuqglSx SzMKWsRDGUH/IGcVAJYyEnQ/VeGMGGe/q4tH+x+LLMGhjQ//SkvbL/QrN3GZcFq9 rio6pC8XizmGqje/1HW+CyEuSo3LrfsLrntE9DukquilDysqRbCcsv2bXFN7Eo9n 6OmAYb/tpNQs6pYqRdz/T2xit3d4og== =BKBF -----END PGP SIGNATURE----- --HcAYCG3uE/tztfnV--