After the latest updates I got a message from Synaptic to the effect that I was missing a public key. My research yielded the following remedy:
Code:
gpg --keyserver pgpkeys.mit.edu --recv-key  A8AA1FAA3F055C03
But when I tried it, I got this:
Code:
gpg: requesting key 3F055C03 from hkp server pgpkeys.mit.edu
gpgkeys: HTTP fetch error 6: Couldn't resolve host 'pgpkeys.mit.edu'
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
(Same result with pgpkeys.ubuntu.org.) I encountered this problem a couple of years ago and found a solution, but I no longer remember what it was. Can anyone help?

The answer to this belongs in some FAQ or other.