public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: William Swanson <swansontec@gmail•com>
To: Kefkius <kefkius@maza•club>
Cc: Bitcoin Dev <bitcoin-development@lists•sourceforge.net>
Subject: Re: [Bitcoin-development] Request For Discussion / BIP number - Multi-Currency Hierarchy For Use In Multisignature Deterministic Wallets
Date: Thu, 9 Apr 2015 15:24:11 -0700	[thread overview]
Message-ID: <CABjHNoQq7OmkmawA-Z-ugd37EFTefh5KqjUThF=fbg1k4u_ThQ@mail.gmail.com> (raw)
In-Reply-To: <5526DE29.1060605@maza.club>

On Thu, Apr 9, 2015 at 1:16 PM, Kefkius <kefkius@maza•club> wrote:
> I've amended the proposal's "Motivation" section slightly for
> clarification. I'm not sure how a "cosigner_index" branch would benefit
> this proposal. Granted, I don't fully understand the benefits of the
> "cosigner_index" branch in BIP-0045. From what I understand, the
> "wallet" branch of my proposal seems to accomplish a similar goal.

Suppose Alice and Bob share a multi-sig wallet. Alice would like to
accept payment from Mallory, and Bob would like to accept payment from
Maude. So, they would each like to create a separate payment address.
If Alice and Bob both generate the same address, the incoming funds
would be mixed together (bad), and Mallory and Maude might learn about
the relationship between Alice and Bob (also bad).

Unfortunately, Alice and Bob are in a place where they can't
communicate (maybe Bob has no cell service). There is no way for Bob
to send a message like "I'm making a request on address_index N,
Alice, please use a different index for your request."

The cosigner_index solves this. When they set up the wallet, Alice and
Bob agree to always use a different value for the cosigner_index. That
way, addresses from Alice will never overlap with addresses from Bob,
since they are on different branches. Doing it this way adds privacy
and doesn't cost anything.

With this added in, your path would be:

m / purpose' / wallet' / coin_type / cosigner_index / change / address_index

XPUB's generated from your wallet would then be compatible with XPUB's
generated by other multi-sig wallets like CoPay, since the
(cosigner_index / change / address_index) structure stays the same.

-William Swanson



  reply	other threads:[~2015-04-09 22:24 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-08  7:05 Kefkius
2015-04-08  7:46 ` William Swanson
2015-04-08 16:28   ` 木ノ下じょな
2015-04-08 16:41     ` William Swanson
2015-04-09 20:16       ` Kefkius
2015-04-09 22:24         ` William Swanson [this message]
2015-04-09 22:37           ` Alan Reiner
2015-04-10  2:02             ` William Swanson
2015-04-10  2:26               ` Alan Reiner
2015-04-16 13:11         ` Vertoe Qhor

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='CABjHNoQq7OmkmawA-Z-ugd37EFTefh5KqjUThF=fbg1k4u_ThQ@mail.gmail.com' \
    --to=swansontec@gmail$(echo .)com \
    --cc=bitcoin-development@lists$(echo .)sourceforge.net \
    --cc=kefkius@maza$(echo .)club \
    /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