This is purely a MultiBit HD thing. Nothing to do with the BIP, unless the
wider community felt that it would be generally useful.

It has nothing to do with internal word list checking and is purely an
additional check to reduce the blockchain search load for SPV clients when
restoring wallets.


On 12 March 2014 19:35, Jean-Paul Kogelman <jeanpaulkogelman@me.com> wrote:

>
>
> On Mar 12, 2014, at 09:49 AM, Gary Rowe <g.rowe@froot.co.uk> wrote:
>
> Jean-Paul, it may be worth noting that the BIP39 word list is integrated
> into Bitcoinj so will likely become the de facto standard for Android,
> Trezor web and several desktop wallets. Anyone deviating from that word
> list would likely find themselves in an isolated pocket.
>
> Regarding the timestamp, MultiBit HD uses a simple timestamp of "number of
> days since midnight of Bitcoin genesis block in UTC with modulo 97 checksum
> appended". Thus a new seed generated on 27 January 2014 would have
> "1850/01" as its checksum.
>
>
> I'm a bit confused, are you changing the way the checksum is calculated,
> or fudging the input seed to produce a specific checksum? Or is checksum in
> this case another value calculated over the mnemonic list?
>
>
> When creating a new wallet the users are tested that they have written the
> timestamp down along with the associated 12/18/24 words.
>
>
> So this is specific to MultiBit HD? Wouldn't it be better to include this
> into the BIP?
>
>