Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Z1Gw4-0007ZK-Ju for bitcoin-development@lists.sourceforge.net; Sat, 06 Jun 2015 16:27:04 +0000 X-ACL-Warn: Received: from mail-qg0-f53.google.com ([209.85.192.53]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1Z1Gw3-0007q8-FE for bitcoin-development@lists.sourceforge.net; Sat, 06 Jun 2015 16:27:04 +0000 Received: by qgg3 with SMTP id 3so14404801qgg.2 for ; Sat, 06 Jun 2015 09:26:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=VVSFus36XxlmAG/x6jkF0rnTFU8RQdRNzF04akYZkgY=; b=mfR8JQs8MAS205EfrIKowsGw10pXMwbACL4XQa1MMgctPXsyS4z4PTVC79wcEVwgsQ ARFc001t2Cw4ingEawpOF9LMul4oPj56qZwOnu9WunhpwXY82/N66bibcTR+58rZ431u GAOuWQWEZ0ne2AVMGc9ebgZ1YCNPdfOfNY9dhmMggVTj30A9eImFQqRiUDysa2foIMrG et4onEwX9tWy8tlWvZbwDeKYshQccRrsKp3RHjU2BZgYJppCvT6IDSj8t33NKfYigC3U f2YG7SJXN/9UfZmbjyadWO3jxOeAPwOO/tM6zBP/wKrEBI9GGsTg2GAFjl/UvV3wgix3 DeRg== X-Gm-Message-State: ALoCoQlGRF+b0uIioCwxzigRluMfSmZID6Wxn3l+RQN/vfPloWtsdj7hTEKsqi+70D+odXDfV7Z+ MIME-Version: 1.0 X-Received: by 10.55.16.33 with SMTP id a33mr17133234qkh.51.1433607641998; Sat, 06 Jun 2015 09:20:41 -0700 (PDT) Received: by 10.96.145.9 with HTTP; Sat, 6 Jun 2015 09:20:41 -0700 (PDT) In-Reply-To: References: Date: Sat, 6 Jun 2015 18:20:41 +0200 Message-ID: From: Kalle Rosenbaum To: Pieter Wuille Content-Type: text/plain; charset=UTF-8 X-Spam-Score: 0.3 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. 0.3 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1Z1Gw3-0007q8-FE Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] BIP for Proof of Payment 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: Sat, 06 Jun 2015 16:27:04 -0000 >> The idea is to simplify implementation. Existing software can be used >> as is to sign and validate PoPs. But I do agree that it would be a >> cleaner specification if we would make the PoP invalid as a >> transaction. I'm open to changes here. I do like the idea to prepend a >> constant string. But that would require changes in transaction signing >> and validation code, wouldn't it? > > > Yes, of course. An alternative is adding a 21M BTC output at the end, or > bitflipping the txin prevout hashes, or another reversible transformation on > the transaction data that is guaranteed to invalidate it. If we do decide to make Pops invalid as transactions, there are a lot of ways to do that. I guess the main question is if we should make Pops invalid as transactions or not. So far I prefer to keep them valid for the above reason. > > I think that the risk of asking people to sign something that is not an > actual transaction, but could be used as one, is very scary. > I would feel comfortable doing it. It's just a matter of trusting your wallet, which you already do with your ordinary transactions. >> >> > Also, I would call it "proof of transaction intent", as it's a >> > commitment to >> > a transaction and proof of its validity, but not a proof that an actual >> > transaction took place, nor a means to prevent it from being double >> > spent. >> >> >> Naming is hard. I think a simpler name that explains what its main >> purpose is (prove that you paid for something) is better than a name >> that exactly tries to explain what it is. > > > "Proof of Payment" indeed does make me think it's something that proves you > paid. But as described, that is not what a PoP does. It proves the ability > to create a particular transaction, and committing to it. There is no actual > payment involved (plus, payment makes me think you're talking about BIP70 > payments, not simple Bitcoin transactions). > >> >> "Proof of transaction >> intent" does not help me understand what this is about. But I would >> like to see more name suggestions. The name does not prevent people >> from using it for other purposes, ie internet over telephone network. > > > I don't understand why something like "Proof of Transaction Intent" would be > incompatible with internet over telephone network either... > No, I meant that it's ok to call it Proof of Payment even though people may use it for other stuff. > -- > Pieter >