{"type":"rich","version":"1.0","author_name":"npub1xvnnyhz8e4eklaakjc9xgm5w8pzkuckt923uacz2cftqdqx23g7q3c5rqg","author_url":"https://nostr.ae/npub1xvnnyhz8e4eklaakjc9xgm5w8pzkuckt923uacz2cftqdqx23g7q3c5rqg","provider_name":"njump","provider_url":"https://nostr.ae","html":"📅 Original date posted:2014-03-26\n📝 Original message:For every branch (say multiple accounts), how would a new wallet be able to\nknow how many sequence items to scan?  It seems like not only do you need\nto have standard rules for the hierarchy, but how the usage can be\ndetected.  The other scanning seems pretty straightforward.  For accounts,\nit seems like you could have a situation where you want to initially set up\n10 different accounts, but only account #10 gets any transactions.  If a\nnew wallet was trying to scan with this seed, it would have to know to keep\nscanning each account until it found the account.  The user would have to\nbe responsible for knowing how many accounts there are, or some rules would\nneed to be in place to not allow creating accounts until earlier accounts\ncan be proven to have existed in the blockchain.  Or I am missing something.\n\n-Allen\n\nOn Wed, Mar 26, 2014 at 3:49 PM, Mike Hearn \u003cmike at plan99.net\u003e wrote:\n\n\u003e Myself, Thomas V (Electrum) and Marek (Trezor) got together to make sure\n\u003e our BIP32 wallet structures would be compatible - and I discovered that\n\u003e only I was planning to use the default structure.\n\u003e\n\u003e Because I'm hopeful that we can get a lot of interoperability between\n\u003e wallets with regards to importing 12-words paper wallets, we brainstormed\n\u003e to find a structure acceptable to everyone and ended up with:\n\u003e\n\u003e   /m/cointype/reserved'/account'/change/n\n\u003e\n\u003e The extra levels require some explanation:\n\u003e\n\u003e    - cointype:  This is zero for Bitcoin. This is here to support two\n\u003e    things, one is supporting alt coins based off the same root seed. Right now\n\u003e    nobody seemed very bothered about alt coins but sometimes feature requests\n\u003e    do come in for this. Arguably there is no need and alt coins could just use\n\u003e    the same keys as Bitcoin, but it may help avoid confusion if they don't.\n\u003e\n\u003e    More usefully, cointype can distinguish between keys intended for\n\u003e    things like multisig outputs, e.g. for watchdog services. This means if\n\u003e    your wallet does not know about the extra protocol layers involved in this,\n\u003e    it can still import the \"raw\" money and it will just ignore/not see the\n\u003e    keys used in more complex transactions.\n\u003e\n\u003e    - reserved is for \"other stuff\". I actually don't recall why we ended\n\u003e    up with this. It may have been intended to split out multisig outputs etc\n\u003e    from cointype. Marek, Thomas?\n\u003e\n\u003e    - account is for keeping essentially wallets-within-a-wallet to avoid\n\u003e    mixing of coins. If you want that.\n\u003e\n\u003e    - change is 0 for receiving addresses, 1 for change addresses.\n\u003e\n\u003e    - n is the actual key index\n\u003e\n\u003e For bitcoinj we're targeting a deliberately limited feature set for hdw v1\n\u003e so I would just set the first three values all to zero and that is a\n\u003e perfectly fine way to be compatible.\n\u003e\n\u003e The goal here is that the same seed can be written down once, and meet all\n\u003e the users needs, whilst still allowing some drift between what wallets\n\u003e support.\n\u003e\n\u003e Pieter made the I think valid point that you can't really encode how keys\n\u003e are meant to be used into just an HDW hierarchy and normally you'd need\n\u003e some metadata as well. However, I feel interop between wallets is more\n\u003e important than arriving at the most perfect possible arrangement, which\n\u003e feels a little like bikeshedding, so I'm happy to just go with the flow on\n\u003e this one.\n\u003e\n\u003e\n\u003e\n\u003e ------------------------------------------------------------------------------\n\u003e\n\u003e _______________________________________________\n\u003e Bitcoin-development mailing list\n\u003e Bitcoin-development at lists.sourceforge.net\n\u003e https://lists.sourceforge.net/lists/listinfo/bitcoin-development\n\u003e\n\u003e\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20140326/48a94563/attachment.html\u003e"}