Fingerprints have been successfully extracted from photographs on a number of occasions (the fingerprints of Angela Merkel made the headlines). To do a secret r

Fingerprints have been successfully extracted from photographs on a number of occasions (the fingerprints of Angela Merkel made the headlines). To do a secret retina scan with other kind of technology is a matter of time. Compared to a password or an RSA key, I would say that biometrics are even dangerous.