Re: [openpgp] Deriving an OpenPGP secret key from a human readable seed

[Phillip Hallam-Baker <[e-mail]>]

On Tue, Oct 15, 2019 at 4:15 PM Jon Callas <joncallas=
[e-mail]> wrote:

> >
> > I hope some of this message makes sense.
> >
>
> I think it makes sense. You're looking at having a way to seed a DRBG
> (PRNG), so that that seed can be used to deterministically generate a key,
> and that seed being reasonably small, and can be encoded in a way that's
> easy to store on paper as well as use for generating the same key later.
>
> This sounds like a good idea, but as others have said, it's more general
> than OpenPGP. Really what you want is a standardized, loadable DRBG, and
> then that DRBG could be bolted into some OpenPGP implementation for key
> generation.
>
> That latter part is software issue and really ought to be generalized
> beyond OpenPGP, and then some implementation of OpenPGP could have the
> feature of creating a key from such a loadable seed.
>
> It sounds useful to some people, but outside the scope of OpenPGP
> documents, just as the design of other RNGs is beyond the scope of OpenPGP
> documents.
>

IETF already has such a function HMAC-KDF. RFC 5869.

The current UDF document does not have the text. I am just finishing up the
code and should have a new draft out tomorrow with the text.