[frigaardj]

True digital cash: secure, anonymous, portable, offline etc.

[codewithcheese]

+ universally and instantly spendable :)

[mdevere]

That's not a problem, that's a product

[thomasrossi]

Offline and secure it's the possibly impossible part, but it would be nice!!

[IkmoIkmo]

That doesn't really have all that much to do with what is considered finance. It's maybe a bit like saying an open issue in computer science is having a great keyboard.