Ladies and gentlemen, I tried to update a debian squeeze OS, with a /etc/apt/sources.list deb http://archive.debian.org/debian/ squeeze contrib main non-free I got GPG error: http://archive.debian.org squeeze Release: The following signatures were invalid: KEYEXPIRED 1520281423 KEYEXPIRED 1501892461 Is there a possibility to avoid this message like in ubuntu, debian wheezy ? Yours sincerely C.Mielech