Guide to setting up your existing YubiKey for GPG & SSH authentication on a Mac 1. Download and install GPG Tools Suite https://gpgtools.org/ 2. Launch GPG Keychain application & import your public key & set it's trust level to Ultimate 3. Edit the file ~/.gnupg/gpg-agent.conf & add the following lines to it enable-ssh-support default-cache-ttl 60 max-cache-ttl 120 pinentry-program /usr/local/MacGPG2/libexec/pinentry-mac.app/Contents/MacOS/pinentry-mac 4. Create or edit bash_profile & add the following lines to it: GPG_TTY=$(/usr/bin/tty) SSH_AUTH_SOCK="$HOME/.gnupg/S.gpg-agent.ssh" export GPG_TTY SSH_AUTH_SOCK gpgconf --launch gpg-agent 5. Source the bash_profile by running the following command: source ~/.bash_profile 6. Test the configuration by running the following command: ssh-add -L If you are able to see ssh-rsa & your key then Profit 🎉