Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of bitpay.com
	designates 209.85.212.173 as permitted sender)
	client-ip=209.85.212.173; envelope-from=jgarzik@bitpay.com;
	helo=mail-wi0-f173.google.com; 
MIME-Version: 1.0
In-Reply-To: <CANEZrP20E5R3D+Em4hordpSpe-e88iyHwyq=WdffsTCpTm+RVA@mail.gmail.com>
References: <CANEZrP1t3Pz3FOgxkxsj+sSgyQhPxfUTdCGXTC7=yxeZkGt-DQ@mail.gmail.com>
	<CAJHLa0NhZ=RuUMts19EUhY6C1+dy1yaje3Hb5Lfm+AqjRRL5uw@mail.gmail.com>
	<CANEZrP20E5R3D+Em4hordpSpe-e88iyHwyq=WdffsTCpTm+RVA@mail.gmail.com>
From: Jeff Garzik <jgarzik@bitpay.com>
Date: Wed, 16 Jul 2014 10:25:17 -0400
Message-ID: <CAJHLa0NcFcRhczf9WWGj+4fYBdYCUBb7Zm__Y5+qhprXL21wUA@mail.gmail.com>
To: Mike Hearn <mike@plan99.net>
Content-Type: text/plain; charset=UTF-8
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Draft BIP for geutxos message
Precedence: list

On the specific issue I raised, the BIP only says "Querying multiple
nodes and combining their answers can be a partial solution to this"
which is not very helpful advice.  That's a partial answer to my
question #2 with zero response for question #3.

This sort of thing really needs a warning label like "use only if you
don't have a trusted solution" and discussion of that choice is
completely absent (question #1).


On Wed, Jul 16, 2014 at 8:37 AM, Mike Hearn <mike@plan99.net> wrote:
> Thanks Jeff.
>
> I do feel like a lot of this is covered in the writeup I attached to the
> implementation pull request, and I went over it again in the ensuing
> discussion, and also in the BIP.
>
> The discussion of how to make it secure is covered in the "Upgrade" section
> of the writeup and in the "Authentication" section of the BIP. Please do let
> me know if these sections are missing something. The ideas discussed there
> are not implemented in this pull request because outside of some special
> cases, it is a very large project that involves a chain fork. You can see
> the start of a solution here:
>
> https://github.com/bitcoin/bitcoin/pull/3977
>
>>
>> If one implements your BIP in a naive manner -- simply find a node, and
>> issue a single query -- they are dangerously exposed to malicious
>> information.  The BIP should describe this major security issue, and
>> describe at least one method of solving it (ditto implementation, if
>> lighthouse has not already solved this).
>
>
> The BIP already does discuss this, in the authentication section.
> Suggestions for how to make it better are welcome.
>
>>
>> Comparison between this and BIP 35 (mempool command) are not apt, as
>> miners and full nodes treat "mempool" returned data just like any other
>> randomly solicited "tx" command on the network.  Unlike "mempool" cmd, this
>> "getutxos" cmd proffers post-verification trusted data.
>
>
> I don't think it does proffer that, but if a part of the BIP could be read
> as doing so, let me know which part and I'll fix it.


-- 
Jeff Garzik
Bitcoin core developer and open source evangelist
BitPay, Inc.      https://bitpay.com/