Hello people,

We are working on some of this stuff. We had some very early draft on
how we envisioned multisig happening. It is all implemented in Haskoin
available as multiple repositories in Github. I am happy to see this
gathering momentum.

Our multisig system uses BIP-0032 HD wallets, and there will soon be
BIP-0039 support for keys compatibility.

Our wallet uses synced trees rooted at the extended pubkeys of the
participants. Currently we are sorting public keys in the scripts to
avoid ambiguity.

Download haskoin-wallet:

cabal install haskoin-wallet

Check out the hw command (installed in ~/.cabal/bin/hw). Use importtx to
bring transactions into the wallet. You must initialize first with a
seed and create an account. It supports both regular and multisig accounts.

Perhaps this can lead to interesting discussions on key exchange, and
the appropriate handling of wallet metadata. I’d love to work on a
proper standard that could lead us to compatible implementations.

This document explains how we do it now:

http://haskoin.com/~xeno/hd-multisig-wallet.html

Cheers!

-- 
Be Happy :)