Reality that so many security experts opt to not speak

Hitoshi Kokumai
3 min readJul 15, 2021


“Touch ID and Face ID: Real biometrics or not?”

Reading reports like the above, probably not a few people would react quickly and critically, mentioning the absence of cancellability of our body features and the privacy concerns it causes.

Few people, however, speak about the fact that the overall security is brought down to the level lower than that of a default password/PIN where the biometrics is used with a default password/PIN in a ‘two-entrance’ deployment (as against ‘two-layer’ deployment).

This security-lowering effect is the inevitable consequence of biometrics being probabilistic, as against deterministic; body features of living animals are unpredictably variable in ever changing environment.

Here is the reality that so many security experts opt to not speak — a two-layer deployment of two authenticators decreases the attack surface, whereas a two-entrance deployment increases the attack surface, thus providing a better convenience to bad guys as closely examined here —

Key References

“What we need to do for NOT achieving Solid Digital Identity”

Removal of Passwords and Its Security Effect

Negative Security Effect of Biometrics Deployed in Cyberspace

External Body Features Viewed as ‘What We Are’

Additional References

For Achieving Solid Digital Identity on Information Security Buzz (Mar/2021)

What We Know for Certain about Authentication Factors

Digital Identity for Global Citizens
Image-to-Code Conversion by Expanded Password System

Summary and Brief History — Expanded Password System

Proposition on How to Build Sustainable Digital Identity Platform

Account Recovery with Expanded Password System

History, Current Status and Future Scenarios of Expanded Password System

Availability-First Approach

Update: Questions and Answers — Expanded Password System and Related Issues

< Videos on YouTube>

Slide: Outline of Expanded Password System (3minutes 2seconds)

Digital Identity for Global Citizens (10minutes — narrated)

Demo: Simplified Operation on Smartphone for consumers (1m41s)

Demo: High-Security Operation on PC for managers (4m28s)

Demo: Simple capture and registration of pictures by users (1m26s)

Slide: Biometrics in Cyber Space — “below-one” factor authentication



Hitoshi Kokumai

Advocate of ‘Identity Assurance by Our Own Volition and Memory’, Inventor of Expanded Password System and Founder of Mnemonic Identity Solutions Limited in UK.