Bitcoin private key from GnuPG secp256k1 secret key?

[NIIBE Yutaka]

Stefan Claas <stefan.claas at posteo.de> wrote:
> just wondering if there is an easy way to generate a Bitcoin secret key
> from a GnuPG  secp256k1 secret key. If so, how would you do that?

I don't know about secret key conversion.

In the past, I did something for public key:

    https://lists.gnupg.org/pipermail/gnupg-devel/2014-January/028147.html

However, soon after this scripting, it occurred the Mt. Gox incident in
Japan.  And I learned that most "users" don't control their private key
for Bitcoin at all, just like general citizen don't control printing of
paper money.  So, no further development for my side.  It was not
committed to GnuPG repo.  (I only have a transaction with the address.)

If someone will make transaction to that address for some amount, I
would resume the development again. :-)
--