external keystore option?

[Mikolaj J. Habryn]

>>>>> "WK" == Werner Koch <wk at gnupg.org> writes:

    WK> The needed key is identified by the 64 bit KeyID.  There is an
    WK> option for a wildcard KeyID in which case gpg tries each
    WK> available secret key in turn.

  Hmm. How can one tell if one has found the right key? Magic in the
plaintext?

    WK> You don't need the secret key for encryption - I guess you are
    WK> thinking of signing a message.

  Yep, or things like signing keys. I presume that in both cases (and
any others?), gpg builds some kind of value which needs to be
encrypted with the secret key and returned (?). I guess the question
boils down to - are there any operations that gpg performs with a
secret key that can't be transformed into an encryption/decryption
with some independent munging of data formats on either side of it?

m.