using various subkeys
Tue Aug 20 17:31:01 2002
On 20 Aug 2002 16:37:20 +0200, Adrian 'Dagurashibanipal' von Bidder said:
> - import this into a new keyring and delete the encryption subkey.
> (the primary secret key contains no cryptographical data, right?)
Correct it is just a stub marked with the ID for a private key
protection algorithm which is the most secure cipher one can create -
there is no data at all.
> - it would be nice if --export-secret-subkeys would accept the
> <subkey-id>! syntax and only export a stripped secret key with that
> - It should be made really clear that the primary of such a key is a
> dummy and does not contain the secret key (--list-secret-keys
> output etc.).
With --list-packets you will notice a "gnu-dummy S2K" for the primary
> Possible issues - I hope I understand this correctly:
> - Keyservers will not work with my new key. (Except LDAP)
Because most can't cope with more than one subkey.
> - PGP users can verify such signatures from version ???
Afaik, current PGP versions can't verify - you have to hope for PGP 8.
> - gpg users can verify such signatures from version ???
Since ever I would say.
> - There is no way to tie a subkey to a userid (if I were to
> use encryption subkeys, this would be a hint 'if you mail me
> at this address, use that subkey).
Correct. User IDs belong top the primary key.
> - if the subkey is compromised, the attacker can sign documents with
> it (of course).
> - if the subkey is compromised, the attacker can sign other keys with
> it (I believe. Or can a key only be signed with the primary?)
No. There used to be a bug in an older GnuPG versions which accidently
used a signing subkey for signing user IDs. But this affected only
very few keys and GnuPG won't verify these key signatures anymore.
> - If I were to import a dummy-primary key into my master keyring, gpg
> merges the keys just right.
I hope so.
> - all this does not affect the management of the user ids in any
> - when the primary secret key is available, gpg will by default use
> it and not the additional signing subkey.
GnuPG always tries to use a subkey first, the primary key is the last
resort. An exception is key signing where only the primary key is