Are Crypto Currencies Money?

Crypto Currencies are neither issued by any state, nor to the best of my knowledge, does any state accept them in payment of taxes. Furthermore they do not represent anyone's IOU either, in that they are "mined" digitally.

A USD, AUD, GBP, and JPY are all sovereign currencies that the respective sovereign countries accept as payment of tax exclusively in their respective jurisdictions. They all have a predetermined face value and can be universally exchanged for real goods and services.

Outside gaming, digital speculation, and tokenism, can anyone explain where Crypto Currencies fit into our monetary and fiscal systems?