Impact of Episodic Memory on Digital Identity

Hitoshi Kokumai
3 min readFeb 16, 2021

The secure digital identity can be achieved only by the joint work of citizens and systems. Episodic image memory plays a big role for the citizens to make it practicable in multiple aspects; it actually enables us to

come up with Expanded Password System as a legitimate successor to text passwords, “Digital Identity for Global Citizens” (90-second video)

convert a set of unforgettable images to a high-entropy complex password, “Image-to-Code Conversion by Expanded Password System”

regenerate the seed of symmetric and asymmetric cryptographic keys on-the-fly, “Account Recovery with Expanded Password System”

thwart nasty phishing attacks effectively, “Detection of Phishing by Episodic Image Memory” (new)

mitigate onerous insiders’ jobs and other persistent attacks, “Advanced Persistent Threats in Digital Identity”

and design a new breed of Brain-to-Machine Interface. “Password & BCI/BMI (Brain-Computer/Machine-Interface)”

A typical definition of Episodic Memory is “the ability to recall and mentally reexperience specific episodes from one’s personal past and is contrasted with semantic memory that includes memory for generic, context-free knowledge.”

While we are advocating a broad use of our episodic memory as the secret credentials for secure digital identity, some people are spreading badly misguided and misguiding perceptions that better security will be achieved by removing the secret credentials from digital identity. Below are our observations on these fallacies.

Bizarre Theory of Password-less Authentication

Removal of Passwords and Its Security Effect

Negative Security Effect of Biometrics Deployed in Cyberspace

Key References

Digital Identity for Global Citizens

What We Know for Certain about Authentication Factors

Summary and Brief History — Expanded Password System

Proposition on How to Build Sustainable Digital Identity Platform

Additional References

External Body Features Viewed as ‘What We Are’

History, Current Status and Future Scenarios of Expanded Password System

Availability-First Approach

Update: Questions and Answers — Expanded Password System and Related Issues (30/June/2020)

< 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

< Media Articles Published in 2020 >

Digital Identity — Anything Used Correctly Is Useful

‘Easy-to-Remember’ is one thing ‘Hard-to-Forget’ is another

Identity Assurance And Teleworking In Pandemic



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.