Periodically copy them to an encrypted external (thumb) drive and keep that in a safe place. Use two if you want to store one of them off-site. Piece of cake wi

Periodically copy them to an encrypted external (thumb) drive and keep that in a safe place. Use two if you want to store one of them off-site. Piece of cake with LUKS and dm-crypt on any modern Linux distro. Just use a long passphrase that you can remember.