All money is bearer cash in the sandbox

JP Koning of the Moneyness blog:

I don't want to pick on them too much, but all these authors are describing a particular implementation of central bank digital money: account-based digital money. There's an entirely different way to design a CBDC, as digital bearer tokens. My guess is that the authors omit this distinction because macroeconomists tend to abstract away from the differences between various types of money.

There is still confusion about sandbox and secure element.  If I have a secure element, then I do honest double entry accounting, and am tamper proof and can treat any money as bearer cash.

What is JP missing?

He fails to understand that digital money means you have a device in your hand.   We are making that device as secure as gold and as intelligent as a central banker (Janet, not Ben).  If you define money that needs a ledger service, fine, but the cash device in our hand can defer the ledger service and pass the cash around as the user decides,  The distinction of bearer cash is gone.

What are the basic requirements needed yo replace the entire global system with digital money?

Give everyone the secure element and make the thousand lines of code in the Redneck S&L trading pit open source. No one needs a ledger system in pure cash.  You need ledger systems when you bet time and space because you have to check that the digits have arrived at the time and space specified.  All that is in the smart layer.  Pure cash support ledger systems of all sorts, for whatever reason, but pure cash itself is ledgerless, and honest and tamper proof.