We released a new version of the Brave Browser today. It is signed with a new GPG key because the old one was about to expire.
If Ubuntu (or derivatives of Debian) users are seeing the error:
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://brave-browser-apt-release.s3.brave.com eoan InRelease: The following signatures were invalid: EXPKEYSIG A8580BDC82D3DC6C Brave Software <firstname.lastname@example.org> W: Failed to fetch https://brave-browser-apt-release.s3.brave.com/dists/eoan/InRelease The following signatures were invalid: EXPKEYSIG A8580BDC82D3DC6C Brave Software <email@example.com> W: Some index files failed to download. They have been ignored, or old ones used instead.
They should run the commands in the install documentation (https://brave-browser.readthedocs.io/en/latest/installing-brave.html#debian-9-ubuntu-14-04-and-mint-17).
Specifically you should import the new GPG key should be run:
curl -s https://brave-browser-apt-release.s3.brave.com/brave-core.asc | sudo apt-key --keyring /etc/apt/trusted.gpg.d/brave-browser-release.gpg add -
Then you can update to the newest Brave Browser package.