#atualizar as keys GPG
/etc/pacman.conf
SigLevel = Required DatabaseOptional
TrustedOnly is a default compiled-in pacman parameter. The default configuration is identical to using the global option of:

SigLevel = Required DatabaseOptional TrustedOnly

Initializing the keyring
To initialize the pacman keyring run:

# pacman-key --init

Managing the keyring
Verifying the master keys
The initial setup of keys is achieved using:

# pacman-key --populate

# pacman -Sy archlinux-keyring

# pacman-key --refresh-keys