Re: Going after bitcoins is probably the result of the increased sanctions
Obviously the DPRK has little difficulty in acquiring / spending hard currencies.
Foreign Guest Workers are paid with Korean People's Won when in the country and a choice of the Euro or US Dollar when exit account balance is paid.
I also carry electronic components in when I visit and I am promptly compensated against the invoice prices. What is amusing, there is a forgery detector light for recipients to use!