1 example for apt-key
# your_comment_here # downloads a key via port 80 in case you're firewalled restrictively: sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys $KEYID
# your_comment_here # downloads a key via port 80 in case you're firewalled restrictively: sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys $KEYID