(1) Unknown Nature of Biometrics ( 2) Overlooked Security in Cyberspace ( 3) Ignored Nature of Humans’ Identity 1. Unknown Nature of Biometrics It is getting known that NIST no longer allows biometrics to be used on its own but requires it to be used ‘only as part of multi-factor authentication with a physical authenticator (something you have)’ in view of the inherent vulnerabilities of biometrics as stated in 5.2.3 ‘Use of Biometrics’ of Digital Identity Guidelines 800-63B. Privacy issues of biometrics are relatively well known. Not a few people are aware that it will be catastrophic when biometrics data are leaked, since it is impossible to change or cancel biometrics data. (‘when’ rather than ‘if’ in view of the long lists of data breach by sophisticated attacks.) But the security aspect of biometrics brought by the co-use with a fallback password is unknown. It is probably due to the indifference of the participants to those ...