Good to hear the bip32 wallet structure is _so_ close to being standardised. For MultiBit HD, we have put in support for 12/18/24 words but have the UI 'suggest' to use 12. You can see this on the wallet creation wizard Gary recently blogged about: https://multibit.org/blog/2014/03/26/multibit-hd-welcome-wizard.html
There's a little combo for the seed length, with 12 as the default. @Thomas. You mention gaps. We are creating new addresses on the UI in a panel marked 'Request' where the user also types in a QR code label and a note to themselves. This gets stored away as a first class 'PaymentRequest'. The UI 'suggests' that each address is used once. There will be some gaps (where the payment request is never paid) but we aren't bulk creating addresses. I am hoping this shouldn't cause Electrum a problem. We are also storing a timestamp (the number of days since the genesis block) to help wallet restore but that is SPV specific. On Thu, Mar 27, 2014, at 01:49 PM, Thomas Voegtlin wrote: > > > Le 27/03/2014 13:49, Mike Hearn a écrit : IP32 allows for a range of entropy sizes and it so happens that > > they picked 256 bits instead of 128 bits. > > > > I'd have thought that there is a right answer for this. 2^128 should not > > be brute forceable, and longer sizes have a cost in terms of making the > > seeds harder to write down on paper. So should this be a degree of freedom? > > > > > Here is what I understand: > > 2^128 iterations is not brute forcable today, and will not be for the > foreseeable future. > > An EC pubkey of length n can be forced in approximately 2^(n/2) > iterations (see http://ecc-challenge.info/) Thus, Bitcoin pubkeys, which > are 256 bits, would require 2^128 iterations. This is why unused > addresses (160 bits hash) are better protected than already used ones. > > However, people tend to believe that a public key of size n requires 2^n > iterations. This belief might have been spread by this popular image: > https://bitcointalk.org/index.php?topic=508880.msg5616146#msg5616146 > > > ------------------------------------------------------------------------------ > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development -- http://bitcoin-solutions.co.uk ------------------------------------------------------------------------------ _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
