Re: [bitcoin-dev] Bip44 extension for P2SH/P2WSH/...

From: Daniel Weigl <Daniel.Weigl@mycelium•com>
To: Bitcoin Protocol Discussion <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Bip44 extension for P2SH/P2WSH/...
Date: Sun, 15 May 2016 14:08:14 +0200	[thread overview]
Message-ID: <573866AE.9070205@mycelium.com> (raw)
In-Reply-To: <CACq0ZD4BvvCryYmO-J9Rof-ogQJ1wNLgmUEU596nuTH=-U8Hag@mail.gmail.com>

Hi,

> 0x40000000 would be the next available to specify witness addresses.
> This is compatible with existing accounts and wallet layouts.

my main concern here is that
 -) every Bip<this-bip>-compatible wallet in the future will have to implement all (then probably) legacy derivation and tx schemes.
 -) it does not fail in a deterministic way, if I import a seed or xPriv/xPub across different capable wallets.
	It is more visible if one account has [no funds/does not show up] at all after an import than if something shows up but you need to make sure that the balance is what you might expect.

Daniel/Mycelium

On 2016-05-13 18:03, Aaron Voisine wrote:
> We use the default BIP32 wallet layout, mentioned in BIP43 as purpose
> "0". We were thinking of of having 4 chains below the "account"
> level, the original 0 and 1 for receive and change addresses, and
> then 0x40000000 and 0x40000001 for P2WPKH-in-P2SH versions of receive
> and change addresses.
> 
> I like the idea of specifying the type of address as a bit field
> flag. 0x80000000 is already used to specify hardened derivation, so
> 0x40000000 would be the next available to specify witness addresses.
> This is compatible with existing accounts and wallet layouts.
> 
> As Daniel mentioned, the downside is that trying to recover on
> non-segwit software will miss segwit receives, however it does avoid
> the problem of having to check multiple address types for each key.
> 
> Aaron Voisine co-founder and CEO breadwallet
> <http://breadwallet.com>
> 
> On Fri, May 13, 2016 at 8:00 AM, Pavol Rusnak via bitcoin-dev
> <bitcoin-dev@lists•linuxfoundation.org
> <mailto:bitcoin-dev@lists•linuxfoundation.org>> wrote:
> 
> On 13/05/16 15:16, Daniel Weigl via bitcoin-dev wrote:
>> 2) Define a new derivation path, parallel to Bip44, but a different
>> 'purpose' (eg. <BipNumber-of-this-BIP>' instead of 44'). Let the
>> user choose which account he want to add ("Normal account",
>> "Witness account").
> 
> We had quite a long discussion in our team some time ago and we
> agreed on that option #2 is much better and we'd like to implement
> this way in myTREZOR.
> 
>> +) Wallet needs only to take care of 1 address per public key
> 
> True, if this BIP only supports P2WPKH.
> 
> P2WSH should probably be handled by another account type and another 
> BIP, anyway.
> 
>> Has any Bip44 compliant wallet already done any integration at this
>> point?
> 
> We have something in the pipeline, but no visible results yet.
> 
> -- Best Regards / S pozdravom,
> 
> Pavol "stick" Rusnak SatoshiLabs.com 
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