How-to verify GPG key of official .ISO images
1. Download an ISO file and the corresponding .sig file from the official sources (see Download Manjaro below).
Install GPG and wget using a Manjaro package manager (pamac or pacman):
pamac install gnupg wget
3. Next, you have 2 possible ways to import Manjaro's keys. Choose one of them:
3.1 Download all keys from the Manjaro Developers from GitLab:
wget gitlab.manjaro.org/packages/core/manjaro-keyring/-/raw/master/manjaro.gpg
Next, import all the keys in the downloaded .gpg file into your gnupg keyring:
gpg --import manjaro.gpg
3.2 If you do not trust GitLab, import Manjaro Build Server's GPG key to your system (afterwards, select the key by entering its number and pressing ENTER):
gpg --keyserver keyserver.ubuntu.com --search-keys 279E7CF5D8D56EC8
4. Finally, verify if the .iso image file was built by the Manjaro Build Server, one of the Manjaro’s Developers, or Philip Müller:
gpg --verify manjaro-xfce-21.0.7-210614-linux510.iso
Compare the key, which was used to sign the .iso file to the key
Check, whether the .ISO was verified by Manjaro Build Server's GPG key ("279E7CF5D8D56EC8"), another Manjaro Developer's key, or the Philip Müller's key which you have imported to your system. If this is the case, you can be sure that your .iso file was built by Philip Müller or another Manjaro Developer.