RFC 4880 says this in the "Security Considerations" part: > * Many security protocol designers think that it is a bad idea to use > a single key for both privacy (encryption) and integrity > (signatures). In fact, this was one of the motivating forces > behind the V4 key format with separate signature and encryption > keys. If you as an implementer promote dual-use keys, you should > at least be aware of this controversy.
Where's your question coming from? As a theoretical musing, it's interesting. In practice, I don't see why you would ever create a subkey with both capabilities set.[1] Also note that it is useful to keep around (and backup) an encryption subkey, to decrypt old stuff. A primary key is useful to backup as it collects certifications. But a signing subkey is not useful to keep around. You might want to refresh your signing subkey more often than your encryption key for that reason. Peter. [1] That doesn't mean there is no reason. -- I use the GNU Privacy Guard (GnuPG) in combination with Enigmail. You can send me encrypted mail if you want some privacy. My key is available at <http://digitalbrains.com/2012/openpgp-key-peter> _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users