How about doing the obvious and searching for that warning? You’ll learn about
Secure Apt and PGP keys.
I did this and am did not find the correct answer.
Long ago I installed debian-archive-keyring via synaptic, this solved
all problems then, but lately I added another archive to pick up come
codecs stuff and started getting those error messages again. I no
longer suscribe to those so I have no problems now - and your answer
would not help.
Would it not be better to tell what needs to be installed if you know
it? Pointing to where the person could find more info is also extremely
helpful but may add to confusion.
