On Sun, Feb 09, 2014 at 03:44:34PM -0500, Peter Todd wrote: > On Sun, Feb 09, 2014 at 01:04:58PM -0500, Peter Todd wrote: > > Alex Mizrahi recently outlined a mechanism(1) based on SIGHASH_SINGLE > > that allows colored coins and similar embedded consensus system assets > > to be securely transferred to another party in exchange for Bitcoins > > atomically. In summary his p2p 2-step-trade mechanism operates as > > follows: > > I'm told there's probably at least one if not more earlier > attributions/reinventions for the 2-step-trade protocol using > SIGHASH_SINGLE. Please reply with them if you have them so we can give > credit where credit is due. Got this: Message-ID: <52418EBA.3080602@monetize.io> Date: Tue, 24 Sep 2013 06:08:10 -0700 From: Mark Friedenbach Organization: Monetize.io Inc. To: Meni Rosenfeld Subject: Re: Freimarkets and investment If assets were tagged you could do a very limited form of pre-signed offers: in: 10 btc SINGLE|ANYONECANPAY out: 1 AAA These are composable, in that you can append the inputs and outputs of multiple offers together and result in a valid transaction. However this is pretty much the limit of what is possible without adding new SIGHASH modes, and if you're going to hard-fork to add tagging, then you might as well go the whole distance with explicit hierarchical sub-transactions as we did with Freimarkets. Cheers, Mark On 9/24/13 5:44 AM, Meni Rosenfeld wrote: > Hi Jorge, > > The video was sent to me by Amos Meiri, I think eToro funded its production. > > Maybe I don't understand SIGHASH_ANYONECANPAY very well. In the > transaction, there will be an output of 1 "my stock" to an initially > unknown address. Can I provide a signature for my input of 1 "my stock" > that will be valid even with the output details provided later? > > In any case, I think that's out of scope for the presentation. > > Meni > > On 24/09/2013 13:10, Jorge Timón wrote: >> Yes, it's a nice presentation. >> I love the video with the chameleons that you link at the end !! >> >> As a little sugestion, I think the biggest advantage of tagging is not >> inflatable assets, it's open binding orders. Even without granular >> subtransactions as freimarket has, you could sign your input (say, >> representing 1 "My stock") and only the output you're interested in >> (say 100 bitstampUSD to myAddress) with SIGHASH_SINGLE | >> SIGHASH_ANYONECANPAY. >> >> Without tagging, you need to know where the inputs come from to check >> they're really bitstampUSD, because the network won't enforce the "100 >> bistampUSD" in your output, any uncolored coins filling the btc >> quantity you wanted to represent those 100 usd will be ok, for miners. >> >> Goog luck with the talk, I'm eager to hear it. >> >> By the way, Mark, the explanation of the blockchain image sounds a >> little bit like hashcasttle, no? well, just merged mining every new >> asset, sounds like jaromil's freecoin too. >> >> >> On 9/24/13, Meni Rosenfeld wrote: >>> Hi Mark, >>> >>> We currently have a more general mathematical framework for the concept of >>> colored coins - a color is a combination of initial state and a kernel >>> function that maps input colors to output colors. Order-based coloring is >>> one such kernel function, tagging is another. As long as you can point at an >>> output and say what its color is, we call it a colored coin system. >>> >>> The blockchain image is a stand-in for "using a new block chain for each >>> asset". >>> >>> Meni >>> >>> On 24/09/2013 00:42, Mark Friedenbach wrote: > Hi Meni, > > I did call Freimarkets "colored coins" in the early days, but the term > colored coin itself within the community seems to have become > identified with the specific proposal of assigning value to specific > satoshis, and running an order based coloring algorithm to determine > asset flow, e.g. Bitcoin-X. Freimarkets allows issuance of entirely > new assets and has explicit tagging of outputs, so we decided to avoid > the phrase "colored coin" so as to keep from confusing people. But as > an academic, yes you are correct. > > You presentation looks great. BTW, what's the first logo for the > "Alternative token systems" slide? Or is that just a stand-in for the > block chain? > > Mark > > On 9/23/13 12:24 PM, Meni Rosenfeld wrote: >>>>>> Hi, >>>>>> >>>>>> As you might know I'm giving a talk about Colored Coins in >>>>>> Amsterdam. >>>>>> >>>>>> My presentation is available at >>>>>> https://bitcoil.co.il/files/Colored Coins.pptx (I'm not posting >>>>>> this link publicly until after the talk). >>>>>> >>>>>> I'll be happy for any feedback. >>>>>> >>>>>> I'm listing Freimarkets as an implementation of Colored Coins. It >>>>>> doesn't look like you're identifying with the term, but it does fit >>>>>> the definition (and though it does obviously do much more than >>>>>> just implement colored coins.) >>>>>> >>>>>> Thanks, Meni >>>> >>> >> > -- 'peter'[:-1]@petertodd.org 0000000076654614e7bf72ac80d47c57bca12503989f4d602538d3cd7892ca7d