gpg --edit-key YOUR_KEYID gpg> keytocard Select destination slot (1=Sign, 2=Encrypt, 3=Authenticate). Repeat for each subkey. Extract the authentication key for SSH:
enable-ssh-support default-cache-ttl 600 max-cache-ttl 7200 pinentry-program /usr/bin/pinentry-curses # or pinentry-mac on macOS Restart the agent: gpg dongle setup
brew install gnupg ykman pinentry-mac :
# PC/SC driver pcsc-driver /usr/lib/libpcsclite.so # Disable CCID (for YubiKey) disable-ccid # Enable card removal notification card-timeout 5 Edit ~/.gnupg/gpg-agent.conf : gpg --edit-key YOUR_KEYID gpg>