To successfully use a Common Access Card (CAC) on a personal computer, downloading and installing Department of Defense (DoD) root certificates is essential. These certificates allow your computer to recognize and trust the identity of official military websites, preventing security warnings and ensuring secure two-factor authentication.
A prompt will ask if you want to trust the certificates; select to finalize the installation. For macOS Users (Manual Method) download cac reader certificates
Even with a functioning CAC reader and drivers, the authentication process may fail because the web browser cannot verify the digital signatures on your card. To successfully use a Common Access Card (CAC)