Technologists still deluding the central banks

Other central banks, notably the UK's Bank of England, have been actively exploring the technology for use as a basis for a new kind of digital currency. And, in June, Canada's central bank unveiled a digital money prototype it has designed, dubbed "CAD-Coin".

The FirstRand Bank paper is, in part, a deeper dive into what a central bank digital currency might look like, invoking the term “sovereign blockchain” as it weighs what officials could use the system for if it was fully realized.

The authors note:

“Once such a sovereign blockchain is created with a [central bank cryptocurrency], other financial instruments such as bonds, equities, derivatives and even land and car registries could migrate to the same sovereign blockchain. This would allow the central bank to conceivably see the creation of all commercial bank assets in an economy.”

Here is the problem, a central banks thinks block chains allows it to see all the assets moves.  
Not so, the incentive to hold or delay block chain verification grows as the central bank looks on.   Central banks will be getting a wholly different view, a compressed view in which the central bank risk is already priced in.