Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1RO9zX-0002fK-Kc for bitcoin-development@lists.sourceforge.net; Wed, 09 Nov 2011 15:23:07 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 74.125.82.53 as permitted sender) client-ip=74.125.82.53; envelope-from=etotheipi@gmail.com; helo=mail-ww0-f53.google.com; Received: from mail-ww0-f53.google.com ([74.125.82.53]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1RO9zT-00009g-He for bitcoin-development@lists.sourceforge.net; Wed, 09 Nov 2011 15:23:07 +0000 Received: by wwg7 with SMTP id 7so2237452wwg.10 for ; Wed, 09 Nov 2011 07:22:57 -0800 (PST) MIME-Version: 1.0 Received: by 10.180.105.102 with SMTP id gl6mr3300544wib.46.1320852177484; Wed, 09 Nov 2011 07:22:57 -0800 (PST) Received: by 10.180.85.1 with HTTP; Wed, 9 Nov 2011 07:22:57 -0800 (PST) Received: by 10.180.85.1 with HTTP; Wed, 9 Nov 2011 07:22:57 -0800 (PST) In-Reply-To: <4EBA9199.7050201@gmail.com> References: <4EBA9199.7050201@gmail.com> Date: Wed, 9 Nov 2011 10:22:57 -0500 Message-ID: From: Alan Reiner To: bitcoin-development@lists.sourceforge.net Content-Type: multipart/alternative; boundary=f46d04426dd4d6fa9304b14edc11 X-Spam-Score: -0.6 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (etotheipi[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1RO9zT-00009g-He Subject: Re: [Bitcoin-development] multisig, op_eval and lock_time/sequence... X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Nov 2011 15:23:07 -0000 --f46d04426dd4d6fa9304b14edc11 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Actually, I'm not sure if your solution works, because it relies on broadcasting a tx to the network that isn't valid. I believe that the first tx in your proposal will be rejected and thus you'll need to exchange the tx's offline. However, third-parties could pretty easily and conveniently host a service for this kind of exchange. --Sent from my overpriced smartphone On Nov 9, 2011 9:43 AM, "Alan Reiner" wrote: > That's what my proposal was for, in BIP 0010: > > https://github.com/genjix/**bips/blob/master/bip-0010.md > > However, I just found a minor problem with it that should be addressed if > we want to enable super-lightweight clients that only sign tx's without > needing the blockchain. Simply that the TxIns don't contain the value of > the TxOuts they are spending, which means the dumb tx-signers with no > blockchain can't tell how much input there is. They can only see the > output values and recipients, which means they can't figure out the tx fe= e, > or how much money is in each of the TxIns they are signing. > > And most users/clients will have access to the blockchain, so it's not a > dealbreaker. But it's something to consider. Otherwise, I think this is= a > big step towards bringing this complicatedprotocol a little closer to > Earth... > > > > > > > On 11/09/2011 05:22 AM, Michael Gr=F8nager wrote: > >> Hi All, >> >> Along with the multisig/op_eval BIPs (11/12) I am considering how the >> actual client functionality could be. >> >> Some of you might already have the solution for this - if not I would >> like to propose the following... >> >> Lets consider the 2 of 3 multisig - and lets say I now have some coins >> hence only redeemable using 2 key signatures. So when I want to spend th= em >> I would do: >> >> 1. from client1 I issue a transaction containing one of the signatures, >> with a locktime e.g. 10 minutes from now and a sequence of 0. This >> transaction is now posted to the p2p network. >> >> 2. client2 discovers the transaction and that it will affect its wallet. >> It hence modifies the transaction to includes also the second signature, >> changes the sequence to 0xFFFFFFFF=3Dfinal and the lock_time to 0 and >> retransmits the transaction. >> >> 3. The transaction is now valid and final and will be approved by the >> miners. >> >> However, for this setup to be possible, we need to reenable the >> replacement of transaction in the client.... >> >> Anyone working on this now ? >> >> Alternatively, the transactions would need to be sent between clients >> using another protocol... >> >> Cheers, >> >> Michael >> >> >> >> ------------------------------**------------------------------** >> ------------------ >> RSA(R) Conference 2012 >> Save $700 by Nov 18 >> Register now >> http://p.sf.net/sfu/rsa-**sfdev2dev1 >> ______________________________**_________________ >> Bitcoin-development mailing list >> Bitcoin-development@lists.**sourceforge.net >> https://lists.sourceforge.net/**lists/listinfo/bitcoin-**development >> > > --f46d04426dd4d6fa9304b14edc11 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

Actually,=A0 I'm not sure if your solution works,=A0 because it reli= es on broadcasting a tx to the network that isn't valid.=A0=A0 I believ= e that the first tx in your proposal will be rejected and thus you'll n= eed to exchange the tx's offline.

However,=A0 third-parties could pretty easily and conveniently host a se= rvice for this kind of exchange.

--Sent from my overpriced smartphone

On Nov 9, 2011 9:43 AM, "Alan Reiner" = <etotheipi@gmail.com> wrot= e:
That's what my proposal was for, in BIP 0010:

https://github.com/genjix/bips/blob/master/bip-0010.md

However, I just found a minor problem with it that should be addressed if w= e want to enable super-lightweight clients that only sign tx's without = needing the blockchain. =A0Simply that the TxIns don't contain the valu= e of the TxOuts they are spending, which means the dumb tx-signers with no = blockchain can't tell how much input there is. =A0They can only see the= output values and recipients, which means they can't figure out the tx= fee, or how much money is in each of the TxIns they are signing.

And most users/clients will have access to the blockchain, so it's not = a dealbreaker. =A0But it's something to consider. =A0Otherwise, I think= this is a big step towards bringing this complicatedprotocol a little clos= er to Earth...






On 11/09/2011 05:22 AM, Michael Gr=F8nager wrote:
Hi All,

Along with the multisig/op_eval BIPs (11/12) I am considering how the actua= l client functionality could be.

Some of you might already have the solution for this - if not I would like = to propose the following...

Lets consider the 2 of 3 multisig - and lets say I now have some coins henc= e only redeemable using 2 key signatures. So when I want to spend them I wo= uld do:

1. from client1 I issue a transaction containing one of the signatures, wit= h a locktime e.g. 10 minutes from now and a sequence of 0. This transaction= is now posted to the p2p network.

2. client2 discovers the transaction and that it will affect its wallet. It= hence modifies the transaction to includes also the second signature, chan= ges the sequence to 0xFFFFFFFF=3Dfinal and the lock_time to 0 and retransmi= ts the transaction.

3. The transaction is now valid and final and will be approved by the miner= s.

However, for this setup to be possible, we need to reenable the replacement= of transaction in the client....

Anyone working on this now ?

Alternatively, the transactions would need to be sent between clients using= another protocol...

Cheers,

Michael



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RSA(R) Conference 2012
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Register now
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