GPG error; The following signatures were invalid KEYEXPIRED [duplicate]

Solution 1:

Actually the problem come from What should I do when I got the KEYEXPIRED error message after an apt-get update?

I can not select the kynana's answer as the best answer so I just put it here. Thank you @Kynan https://serverfault.com/users/53358/kynan

To find any expired repository keys and their IDs, use apt-key as follows:

sudo apt-key list | grep expired

You will get a result similar to the following:

pub   4096R/BE1DB1F1 2011-03-29 [expired: 2014-03-28]

The key ID is the bit after the / i.e. BE1DB1F1 in this case.

To update the key, run

sudo apt-key adv --recv-keys --keyserver keys.gnupg.net BE1DB1F1