public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: Jonas Schnelli <dev@jonasschnelli•ch>
To: Aaron Voisine <voisine@gmail•com>,
	Bitcoin Protocol Discussion
	<bitcoin-dev@lists•linuxfoundation.org>,
	bfd@cock•lu
Subject: Re: [bitcoin-dev] Committed bloom filters for improved wallet performance and SPV security
Date: Wed, 4 Jan 2017 08:47:10 +0100	[thread overview]
Message-ID: <f335731c-3928-6694-5ed8-aa1999b401f1@jonasschnelli.ch> (raw)
In-Reply-To: <CACq0ZD7XT_h8ADptKA0uBT7617fvvgh3uGndkc08RZUSQM2yQg@mail.gmail.com>


[-- Attachment #1.1: Type: text/plain, Size: 2215 bytes --]

Hi

> Unconfirmed transactions are incredibly important for real world use.
> Merchants for instance are willing to accept credit card payments of
> thousands of dollars and ship the goods despite the fact that the
> transaction can be reversed up to 60 days later. There is a very large
> cost to losing the ability to have instant transactions in many or
> even most situations. This cost is typically well above the fraud risk. 
>
> It's important to recognize that bitcoin serves a wide variety of use
> cases with different profiles for time sensitivity and fraud risk.
>
I agree that unconfirmed transactions are incredibly important, but not
over SPV against random peers.

If you offer users/merchants a feature (SPV 0-conf against random
peers), that is fundamentally insecure, it will – sooner or later – lead
to some large scale fiasco, hurting Bitcoins reputation and trust from
merchants.

Merchants using and trusting 0-conf SPV transactions (retrieved from
random peers) is something we should **really eliminate** through
education and by offering different solution.

There are plenty, more sane options. If you can't run your own full-node
as a merchant (trivial), maybe co-use a wallet-service with centralized
verification (maybe use two of them), I guess Copay would be one of
those wallets (as an example). Use them in watch-only mode.

For end-users SPV software, I think it would be recommended to...
... disable unconfirmed transactions during SPV against random peers
... enable unconfirmed transactions when using SPV against a trusted
peer with preshared keys after BIP150
... if unconfirmed transactions are disabled, show how it can be enabled
(how to run a full-node [in a box, etc.])
... educate, inform users that a transaction with no confirmation can be
"stopped" or "redirected" any time, also inform about the risks during
low-conf phase (1-5).

I though see the point that it's nice to make use of the "incoming
funds..." feature in SPV wallets. But – for the sake of stability and
(risk-)scaling – we may want to recommend to scarify this feature and –
in the same turn – to use privacy-preserving BFD's.

</jonas>



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  parent reply	other threads:[~2017-01-04  7:47 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-09  8:26 bfd
2016-05-09  8:57 ` Gregory Maxwell
2016-05-11 20:06 ` Bob McElrath
2016-05-11 20:29   ` Bob McElrath
2016-07-28 21:07     ` Leo Wandersleb
2017-01-06 22:07       ` Erik Aronesty
2017-01-03 20:24     ` bfd
     [not found] ` <77b6dd25-0603-a0bd-6a9e-38098e5cb19d@jonasschnelli.ch>
2017-01-03 20:18   ` bfd
2017-01-03 22:18     ` Aaron Voisine
2017-01-03 22:28       ` bfd
2017-01-03 23:06       ` adiabat
2017-01-03 23:46         ` Aaron Voisine
2017-01-04  0:10           ` bfd
2017-01-04  0:36             ` Aaron Voisine
2017-01-04  6:06               ` Eric Voskuil
2017-01-04 16:13         ` Leo Wandersleb
2017-01-04  7:47       ` Jonas Schnelli [this message]
2017-01-04  8:56         ` Aaron Voisine
2017-01-04 10:13           ` Jorge Timón
2017-01-04 11:00             ` Adam Back
2017-01-06  2:15           ` bfd
2017-01-06  7:07             ` Aaron Voisine
2017-01-05  7:06         ` Chris Priest
2017-01-05  7:45           ` Eric Voskuil
2017-01-05 14:48             ` Christian Decker
2017-01-06 20:15             ` Chris Priest
2017-01-06 21:35               ` James MacWhyte
2017-01-06 21:50                 ` Eric Voskuil
2017-01-06  2:04           ` bfd
2017-03-15 22:36             ` Tom Harding
2017-03-16  0:25               ` bfd
2017-03-16 15:05                 ` Tom Harding
2017-02-17  0:28 ` Chris Belcher
2017-04-01 23:49   ` bfd

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f335731c-3928-6694-5ed8-aa1999b401f1@jonasschnelli.ch \
    --to=dev@jonasschnelli$(echo .)ch \
    --cc=bfd@cock$(echo .)lu \
    --cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
    --cc=voisine@gmail$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox