gnupg private-keys encryption

[Robert J. Hansen]

> How can I control the encryption on the private-key?

Change the passphrase.  Just changing configuration file preferences
doesn't change the way the key is stored on disk.  It only says "the
next time you have to alter the way the key is stored on disk, use these
new parameters".

Changing the passphrase on the key will force GnuPG to write it out to
disk again, at which point your new preferences will take effect.

Warning: this information was correct for GnuPG 1.4 and 2.0.  I'm not
sure about 2.2, as I've never needed to do it on 2.2.