I realize that this post to your thread is a bit late, sorry that some of us are not replying as quickly as hoped for by others posting. Not all of us do visit this helpful forums everyday, you will have to pardon us.
Nevertheless, your issue might be related to a time issue. Not 100 percent sure, but I’m throwing it out there just in case.
From the Arch Wiki on this issue
There are multiple possible sources of this problem:
Outdated archlinux-keyring package.
Your ISP blocked the port used to import PGP keys.
Your pacman cache contains copy of unsigned packages from previous attempts.
When you do
does that correspond to your local time at this moment? If it does not, you can set the time like this:
timedatectl set-time "yyyy-MM-dd hh:mm:ss"
timedatectl set-time "2014-10-04 12:35:14"
Please do the following and make sure that it is set to RTC
timedatectl | grep local
You can also try to clean the pacman cache. You can try to do the following;
sudo pacman -Sc
sudo pacman-key --populate-archlinux along with an update/upgrade.
The other thing that you can try and this might be a good possibility is to reset all of the keys.
/etc/pacman.d is there a gnupg file inside that folder? There should be. If there is, remove gnupg as root and do the following:
sudo pacman-key --init
Let’s try those first and see what the results are.