Thanks for starting the discussion on finding a better structure. For me, the most important thing is either we're 100% interoperable or 0%. There should not be anything inbetween, as users will delete seeds without knowing there is still money in them on another implementation. I heard from multiple sources that using this standard some wallets will only see a subset of the addresses/keys of some other wallets. Implementation differences can always happen (and should addresses as bugs), but I think its unacceptable that this source of issues is by design.
I suggest we agree on an even simpler least common denominator and wallets that want to implement some feature on top of that can do but are encouraged to pick a totally different "cointype". I guess that would mean removing reserved and account. I'm still thinking it might be a good idea to have a separate chain for "refunds". Refunds will be rarely used and thus need a much slower moving window than receiving addresses or change. On 03/26/2014 09:49 PM, Mike Hearn wrote: > Myself, Thomas V (Electrum) and Marek (Trezor) got together to make sure > our BIP32 wallet structures would be compatible - and I discovered that > only I was planning to use the default structure. > > Because I'm hopeful that we can get a lot of interoperability between > wallets with regards to importing 12-words paper wallets, we > brainstormed to find a structure acceptable to everyone and ended up with: > > /m/cointype/reserved'/account'/change/n > > The extra levels require some explanation: > > * cointype: This is zero for Bitcoin. This is here to support two > things, one is supporting alt coins based off the same root seed. > Right now nobody seemed very bothered about alt coins but sometimes > feature requests do come in for this. Arguably there is no need and > alt coins could just use the same keys as Bitcoin, but it may help > avoid confusion if they don't. > > More usefully, cointype can distinguish between keys intended for > things like multisig outputs, e.g. for watchdog services. This means > if your wallet does not know about the extra protocol layers > involved in this, it can still import the "raw" money and it will > just ignore/not see the keys used in more complex transactions. > > * reserved is for "other stuff". I actually don't recall why we ended > up with this. It may have been intended to split out multisig > outputs etc from cointype. Marek, Thomas? > > * account is for keeping essentially wallets-within-a-wallet to avoid > mixing of coins. If you want that. > > * change is 0 for receiving addresses, 1 for change addresses. > > * n is the actual key index > > For bitcoinj we're targeting a deliberately limited feature set for hdw > v1 so I would just set the first three values all to zero and that is a > perfectly fine way to be compatible. > > The goal here is that the same seed can be written down once, and meet > all the users needs, whilst still allowing some drift between what > wallets support. > > Pieter made the I think valid point that you can't really encode how > keys are meant to be used into just an HDW hierarchy and normally you'd > need some metadata as well. However, I feel interop between wallets is > more important than arriving at the most perfect possible arrangement, > which feels a little like bikeshedding, so I'm happy to just go with the > flow on this one. > > > > ------------------------------------------------------------------------------ > > > > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > ------------------------------------------------------------------------------ _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
