Andrew Haldane said one solution would be for the Bank of England to issue a state-backed digital currency based on bitcoin. Supporting this initiative would be a negative interest rate levied on paper currency relative to the digital currency, with these measures do you think there is more possibilities that sometime:
Paper money will be banned entirely?
How long do you think that happens?
would it work?
What security and privacy risks would it raise?
And how would public and privately issued monies interact?
No, I do not think that paper money will be banned, at least not anytime soon. Governments are in full control of today's currency, and it would make no sense for them to get rid of it and move to a cryptocurrency or any other form of payment online. It would be much harder for them to control / manipulate it to their favour.
However, I do see an end to paper money in the next few decades, maybe even earlier. It has been used for quite some time now and has become 'outdated' compared to today's society. If we were to invest more time, money and energy into developing secure, fast online transaction methods (Bitcoin per se) then paper money would definitely come to a halt.