I'm just thinking about it from a merchant's point of view. A merchant is only interested in knowing if it's "credit money" (which to them is digital) or "cash money" (which is immediate). If you say "digital cash" to a merchant thats like saying "credit-cash" and loads it with ambiguity.

i.e. To a merchant the word "digital" equals PDQ machines and that means fees, adverse chargebacks and all. So it has negative conotations.

To make it unambiguous (for the merchant) I think it should be cash. Private-Instant-Cash.