Description: Invalid or corrupted PGP signature

Additional info:
* package version(s)
* config and/or log files etc.

I don't have any corrupt versions of the package in my cache and have uninstalled it from my system, the issue was not resolved. Other packages work fine.

todd@iwakura ~ $ sudo pacman -S confuse
resolving dependencies...
looking for conflicting packages...

Packages (1) confuse-2.8-1

Total Download Size: 0.03 MiB
Total Installed Size: 0.11 MiB

:: Proceed with installation? [Y/n]
:: Retrieving packages ...
confuse-2.8-1-x86_64 33.8 KiB 325K/s 00:00 [###################################] 100%
(1/1) checking keys in keyring [###################################] 100%
(1/1) checking package integrity [###################################] 100%
error: confuse: signature from "Thorsten Töpper <atsutane@freethoughts.de>" 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)).
Do you want to delete it? [Y/n] ]
error: failed to commit transaction (invalid or corrupted package (PGP signature))
Errors occurred, no packages were upgraded.

Steps to reproduce:

~$ pacman -S confuse