Just one of the problems with all crypto currency is that it's cloud money. That is, it's 100% dependent on internet technology. In war one of the first things attacked is communications, and if the attacker has nuclear weapons then a single high altitude detonation that produces an electromagnetic pulse will take out the grid and communications in a large area. A large solar flare such as the
1859 Carrington event could disrupt, damage or destroy much of the internet. By the time the internet is repaired many will find their crypto money has disappeared into a cloud of obscuration.