Re: [Bitcoin-development] Multisign payment protocol?

[Miron <c1.sf-bitcoin@niftybox.net>]

On Tue, 2014-03-11 at 16:18 +0100, Mike Hearn wrote:
> You can follow HDW progress in bitcoinj on this branch:
> 
> 
>   https://github.com/bitcoinj/bitcoinj/commits/keychain
> 
>    
> I've been working on it for a couple of months now. Electrum (Thomas
> V) is also making good progress, and Trezor already uses HD wallets. I
> think most popular end user wallets except blockchain.info and Bitcoin
> Core will support HDW soon enough.

Interestingly, Blockchain's android wallet is based on Android Wallet /
bitcoinj.  So with HD in bitcoinj we would get Multibit, Android Wallet
(Andreas Schildbach's) and remove one roadblock to Blockchain going HD.
Electrum HD seems more or less ready.  So I'm optimistic that we'll see
a pretty fast transition to HD for the majority of the user base.

HD is important for some multisig flows, including the watchdog type
where you want to detect change going back to the wallet.

> 
> At any rate, as Gavin said already, the best way to make a feature you
> want happen is just to write it. Devrandom is already working on a
> watchdog service, as is another group (TrustedCoin), and that's an
> obvious use for multisig/p2sh. They have API's already, it's just a
> case of standardising them once we get more experience.

We have a proposed flow for watchdog type multisig
here:

https://cryptocorp.co/technology.htm

and a reference implementation off the Electrum 2.0 branch.

It actually works just like a regular spend from a UX point of view,
unless the watchdog decides that it needs a second factor for a risky
transaction.  With a risky transaction, the user just gets a
callback or enters an OTP.

-- 
Miron