Physical Covid certificates are also not secure at all. They are easy to copy or fake. Any scheme which simply puts a cryptographic number on a some Physical card - or behind a regular QR is not secure. A simple photocopy will work just as well as the original. Not to mention Photoshop. But there is actually a new way to make physical things - like printed Covid vaccination cards - provably unique and authentic. Much…
meanwhile ime most places with vaccine requirement accept a photo on my cell phone - not exactly cryptographically signed stuff over here.