To: Chris Priest <cp368202@ohiou.edu>,
	Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>,
	Jonas Schnelli <dev@jonasschnelli.ch>
References: <71d822e413ac457a530e1c367811cc24@cock.lu>
	<77b6dd25-0603-a0bd-6a9e-38098e5cb19d@jonasschnelli.ch>
	<74aeb4760316b59a3db56c0d16d11f28@cock.lu>
	<CACq0ZD7XT_h8ADptKA0uBT7617fvvgh3uGndkc08RZUSQM2yQg@mail.gmail.com>
	<f335731c-3928-6694-5ed8-aa1999b401f1@jonasschnelli.ch>
	<CAAcC9ysdaK1DqBBRvBM=7uHFnM7WW23R61v68xrAMj3rWJfqdg@mail.gmail.com>
From: Eric Voskuil <eric@voskuil.org>
Message-ID: <347a0909-affd-da0c-f7f8-09fa76bcb279@voskuil.org>
Date: Wed, 4 Jan 2017 23:45:18 -0800
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Subject: Re: [bitcoin-dev] Committed bloom filters for improved wallet
 performance and SPV security
Precedence: list

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On 01/04/2017 11:06 PM, Chris Priest via bitcoin-dev wrote:
> On 1/3/17, Jonas Schnelli via bitcoin-dev
> <bitcoin-dev@lists.linuxfoundation.org> wrote:
>>
>> There are plenty, more sane options. If you can't run your own full-no=
de
>> as a merchant (trivial), maybe co-use a wallet-service with centralize=
d
>> verification (maybe use two of them), I guess Copay would be one of
>> those wallets (as an example). Use them in watch-only mode.
>=20
> The best way is to connect to the mempool of each miner and check to
> see if they have your txid in their mempool.
>=20
> https://www.antpool.com/api/is_in_mempool?txid=3D334847bb...
> https://www.f2pool.com/api/is_in_mempool?txid=3D334847bb...
> https://bw.com/api/is_in_mempool?txid=3D334847bb...
> https://bitfury.com/api/is_in_mempool?txid=3D334847bb...
> https://btcc.com/api/is_in_mempool?txid=3D334847bb...
>=20
> If each of these services return "True", and you know those services
> so not engage in RBF, then you can assume with great confidence that
> your transaction will be in the next block, or in a block very soon.
> If any one of those services return "False", then you must assume that
> it is possible that there is a double spend floating around, and that
> you should wait to see if that tx gets confirmed. The problem is that
> not every pool runs such a service to check the contents of their
> mempool...
>=20
> This is an example of mining centralization increasing the security of
> zero confirm.

A world connected up to a few web services to determine payment validity
is an example of a bitcoin security catastrophe.

e


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