different passwords for subkeys of the same masterkey

[Faramir]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Hello,

El 21-01-2015 a las 7:58, s7r escribió:
> Thank you very much for your reply.

...
> I have the public key of John Doe <john.doe at example.com> . He has
> more UserIDs associated with the same masterkey, as follows: John
> Doe <john.doe at example.com> John Smith <john.smith at foo.com> Bob
> Jones <bob.jones at test.net> Primary UserID is John Doe
> <john.doe at example.com>
> 
> I want to sign this key, but just to confirm the UserID John Smith 
> <john.smith at foo.com> and not sign/certify his other UserIDs
> belonging to the same key. Is this possible?

  Yes, using the command line, but I'm not sure what are the commands
involved, since I use a GUI that lets me select the key I want to
sign, and the key I want to use to issue the signature (after that,
the GUI invokes GPG, gives it the command and parameters and let you
continue the process using GPG on the command line), you will have to
check the manual to figure out how to do that from command line. Once
you get there, you will get a screen asking if you are sure you want
to sign all the UIDs, if you say NO, it will suggest you to select the
UIDs you want to sign (you will notice each UID is numbered from 1 to
n). Enter the number of a UID to select it, press enter, and then you
can either select another, or enter the sign (or lsign for local
signatures, or tsign for trust signatures) command and follow the
dialog to complete the signature process. I don't remember, but I
think you may need to end with the SAVE command to save the changes to
the key. It's been a long time since I signed a key.

  Best Regards
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iQEcBAEBCAAGBQJUwCxFAAoJEMV4f6PvczxAr1AH/jQA69wZb9IMDt9k2hvGq/5B
zjC32PtYL8doLM8O9KwBdKPMTS7GulaZCKLKgcMqe/vvCnY3imhBs6cST+vVIjvI
+saqkwA2yu28V1cjw1ncBFvopTvdiT8MIDwv30wusrYMEq+iL6gLuZSPmUnnFQxB
Nx+r3gf6sEnI45HHPaeyMleCUIw/aPMzkRtjJMYgfYJ247HvvDzUPk2ho/n8dn75
fAudm1HmXav4nvZvs9FmoMttLLx4P+j9BrJZKdIVtbzqwanAbJBOukP87BGsvUiE
yj3pn7RwhKPHYXbNgz/8yDQvIrDt9csCn2blyP7lU8b6owUxPGCpVBZ687D4zSw=
=htf7
-----END PGP SIGNATURE-----