archlinux-keyring 20160123-1 is needed, but not available, if testing isn't used.
Packages (11) boost-1.60.0-2 boost-libs-1.60.0-2 cmake-3.4.2-1 confuse-2.8-1 dhcpcd-6.10.1-1 libvpx-1.5.0-4 ntp-4.2.8.p6-1 openmpi-1.10.2-1 pacman-mirrorlist-20160124-1 python-setuptools-1:19.6-1 python2-setuptools-1:19.6-1
error: confuse: signature from "Thorsten Töpper email@example.com" is unknown trust :: File /var/cache/pacman/pkg/confuse-2.8-1-x86_64.pkg.tar.xz is corrupted (invalid or corrupted package (PGP signature)).
# pacman-key --refresh-keys --updatedb
This fixed the issue with the signature. However, the current keyring package isn't available.
"archlinux-keyring 20160123-1" - https://www.archlinux.org/packages/testing/any/archlinux-keyring/ "archlinux-keyring 20151220-1" - https://www.archlinux.org/packages/core/any/archlinux-keyring/
# pacman -Q archlinux-keyring archlinux-keyring 20151220-1 # pacman -Si archlinux-keyring | grep Ver Version : 20151220-1
My apologies, after taking a look at the archive, I noticed that this issue already was reported.
I couldn't notice it, since there's an issue with my account:
"Note: your list delivery is currently disabled; it was disabled due to excessive bounces. The last bounce was received on 12-Jan-2016."