diff options
author | Alan Reiner <etotheipi@gmail.com> | 2013-06-19 15:00:42 -0400 |
---|---|---|
committer | bitcoindev <bitcoindev@gnusha.org> | 2013-06-19 19:00:58 +0000 |
commit | 7f1ae1af4cb46535ba3618eaa2f01df4bc1b187f (patch) | |
tree | 8293a5e74e6d26438d74f4e814ca8fba4d13b35a | |
parent | 17d6a072165cb6a35a60182851a7e110b63cff35 (diff) | |
download | pi-bitcoindev-7f1ae1af4cb46535ba3618eaa2f01df4bc1b187f.tar.gz pi-bitcoindev-7f1ae1af4cb46535ba3618eaa2f01df4bc1b187f.zip |
Re: [Bitcoin-development] Optional "wallet-linkable" address format - Payment Protocol
-rw-r--r-- | f3/0ab09f14bde4a13aecbadff956535a46a4c380 | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/f3/0ab09f14bde4a13aecbadff956535a46a4c380 b/f3/0ab09f14bde4a13aecbadff956535a46a4c380 new file mode 100644 index 000000000..61479ab8d --- /dev/null +++ b/f3/0ab09f14bde4a13aecbadff956535a46a4c380 @@ -0,0 +1,231 @@ +Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] + helo=mx.sourceforge.net) + by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) + (envelope-from <etotheipi@gmail.com>) id 1UpNco-0002Ep-H8 + for bitcoin-development@lists.sourceforge.net; + Wed, 19 Jun 2013 19:00:58 +0000 +Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of gmail.com + designates 209.85.223.173 as permitted sender) + client-ip=209.85.223.173; envelope-from=etotheipi@gmail.com; + helo=mail-ie0-f173.google.com; +Received: from mail-ie0-f173.google.com ([209.85.223.173]) + by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) + (Exim 4.76) id 1UpNcn-0000dT-Il + for bitcoin-development@lists.sourceforge.net; + Wed, 19 Jun 2013 19:00:58 +0000 +Received: by mail-ie0-f173.google.com with SMTP id k13so14330599iea.32 + for <bitcoin-development@lists.sourceforge.net>; + Wed, 19 Jun 2013 12:00:52 -0700 (PDT) +X-Received: by 10.50.136.230 with SMTP id qd6mr2053027igb.4.1371668452227; + Wed, 19 Jun 2013 12:00:52 -0700 (PDT) +Received: from [192.168.1.85] (c-76-111-96-126.hsd1.md.comcast.net. + [76.111.96.126]) + by mx.google.com with ESMTPSA id ir8sm7396363igb.6.2013.06.19.12.00.51 + for <multiple recipients> + (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); + Wed, 19 Jun 2013 12:00:51 -0700 (PDT) +Message-ID: <51C1FFDA.1050308@gmail.com> +Date: Wed, 19 Jun 2013 15:00:42 -0400 +From: Alan Reiner <etotheipi@gmail.com> +User-Agent: Mozilla/5.0 (X11; Linux x86_64; + rv:17.0) Gecko/20130510 Thunderbird/17.0.6 +MIME-Version: 1.0 +To: Adam Back <adam@cypherspace.org> +References: <51BFD886.8000701@gmail.com> <20130619142510.GA17239@crunch> + <51C1C288.4000305@gmail.com> + <20130619152815.GA14729@netbook.cypherspace.org> + <20130619183657.GA16708@netbook.cypherspace.org> +In-Reply-To: <20130619183657.GA16708@netbook.cypherspace.org> +X-Enigmail-Version: 1.5.1 +Content-Type: multipart/alternative; + boundary="------------050302010302050007010608" +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: 1UpNcn-0000dT-Il +Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net> +Subject: Re: [Bitcoin-development] Optional "wallet-linkable" address format + - Payment Protocol +X-BeenThere: bitcoin-development@lists.sourceforge.net +X-Mailman-Version: 2.1.9 +Precedence: list +List-Id: <bitcoin-development.lists.sourceforge.net> +List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>, + <mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe> +List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development> +List-Post: <mailto:bitcoin-development@lists.sourceforge.net> +List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help> +List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>, + <mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe> +X-List-Received-Date: Wed, 19 Jun 2013 19:00:58 -0000 + +This is a multi-part message in MIME format. +--------------050302010302050007010608 +Content-Type: text/plain; charset=ISO-8859-1 +Content-Transfer-Encoding: 7bit + +On 06/19/2013 02:36 PM, Adam Back wrote: +> This maybe simpler and trivially compatible with existing type2 public +> keys +> (ones that are multiples of a parent public key): send an ECDSA +> signature of +> the multiplier, and as we know you can compute ("recover") the parent +> public +> key from an the ECDSA signature made using it. +> +> Adam +> +> On Wed, Jun 19, 2013 at 05:28:15PM +0200, Adam Back wrote: +>> [q-th root with unknown no discrete log artefact] +>> +>> If it was a concern I guess you could require a proof of knowledge of +>> discrete log. ie as well as public key parent, multiplier the +>> address must +>> include ECDSA sig or Schnorr proof of knowledge (which both demonstrate +>> knowledge of the discrete log of Q to base G.) + +It's a cool trick but requiring a signature on each multiplier defeats +one of the purposes of a deterministic wallet. I don't want to have to +explicitly export a whole bunch of signatures from my offline system +just to exercise this address option. The "observer wallet" should be +able to do anything it needs to on its own, without help from the +offline wallet. + +Unless you mean that there is a one-time signature from the offline +computer that works for all addresses, that can be exported with the +observer wallet...? If all you want to do is prove that /someone/ owns +that private key, you could send {Sign(MagicString), Multiplier}. So +it becomes one signature operation *per wallet*, but creating new +wallets would require going back to the offline computer for that +one-time signature. That's better than the alternative, but it's still +extra bloat for the wallet apps. + +Either way, I'm not convinced that these are a problem for the specified +use cases I outlined. In cases where you have a persistent business +relationship, they need to verify the parent public key exchange +anyway. After that, the software doesn't technically require the +transmission of the PubKey, it only needs the Name/ID of the party and +the multiplier and it will fetch the PubKey from its data store. Or it +is transmitted and the payer verifies it's correct. Computing an +alternate {PubKey', Mult'} that produces the same address and then using +it in a MitM attack doesn't work here if the two parties pre-verified +the public keys. + +In the case that a business is checking whether the cashout address of a +customer is the same as the last time: if the first payout was not +replaced by an attacker, then the business already has the correct +public key in their DB and a replacement of further payout requests will +fail validation. If the first payout was replaced... well that could've +been done anyway (with or without this alternate form), and the customer +wouldn't have received their money and the whole process would be +flagged and terminated before further transactions. + +-Alan + + + +--------------050302010302050007010608 +Content-Type: text/html; charset=ISO-8859-1 +Content-Transfer-Encoding: 7bit + +<html> + <head> + <meta content="text/html; charset=ISO-8859-1" + http-equiv="Content-Type"> + </head> + <body text="#000000" bgcolor="#FFFFFF"> + On 06/19/2013 02:36 PM, Adam Back wrote:<br> + <blockquote + cite="mid:20130619183657.GA16708@netbook.cypherspace.org" + type="cite">This maybe simpler and trivially compatible with + existing type2 public keys + <br> + (ones that are multiples of a parent public key): send an ECDSA + signature of + <br> + the multiplier, and as we know you can compute ("recover") the + parent public + <br> + key from an the ECDSA signature made using it. + <br> + <br> + Adam + <br> + <br> + On Wed, Jun 19, 2013 at 05:28:15PM +0200, Adam Back wrote: + <br> + <blockquote type="cite">[q-th root with unknown no discrete log + artefact] + <br> + <br> + If it was a concern I guess you could require a proof of + knowledge of + <br> + discrete log. ie as well as public key parent, multiplier the + address must + <br> + include ECDSA sig or Schnorr proof of knowledge (which both + demonstrate + <br> + knowledge of the discrete log of Q to base G.) + <br> + </blockquote> + </blockquote> + <br> + It's a cool trick but requiring a signature on each multiplier + defeats one of the purposes of a deterministic wallet. I don't want + to have to explicitly export a whole bunch of signatures from my + offline system just to exercise this address option. The "observer + wallet" should be able to do anything it needs to on its own, + without help from the offline wallet. <br> + <br> + Unless you mean that there is a one-time signature from the offline + computer that works for all addresses, that can be exported with the + observer wallet...? If all you want to do is prove that <i>someone</i> + owns that private key, you could send {Sign(MagicString), + Multiplier}. So it becomes one signature operation <b>per wallet</b>, + but creating new wallets would require going back to the offline + computer for that one-time signature. That's better than the + alternative, but it's still extra bloat for the wallet apps.<br> + <br> + Either way, I'm not convinced that these are a problem for the + specified use cases I outlined. In cases where you have a + persistent business relationship, they need to verify the parent + public key exchange anyway. After that, the software doesn't + technically require the transmission of the PubKey, it only needs + the Name/ID of the party and the multiplier and it will fetch the + PubKey from its data store. Or it is transmitted and the payer + verifies it's correct. Computing an alternate {PubKey', Mult'} that + produces the same address and then using it in a MitM attack doesn't + work here if the two parties pre-verified the public keys. <br> + <br> + In the case that a business is checking whether the cashout address + of a customer is the same as the last time: if the first payout was + not replaced by an attacker, then the business already has the + correct public key in their DB and a replacement of further payout + requests will fail validation. If the first payout was replaced... + well that could've been done anyway (with or without this alternate + form), and the customer wouldn't have received their money and the + whole process would be flagged and terminated before further + transactions.<br> + <br> + -Alan<br> + <br> + <br> + </body> +</html> + +--------------050302010302050007010608-- + + |