Why not just reward people for mining the way bitcoin does? This way it is a non-centralized government recognized currency that also pays for govt activities.
Anyone in the world could mine the currency for the govt, and it would be taxed world wide, and then spent in the country by the govt.
*facepalm* good point.
I guess then the only issue would be people picking between a distributed decentralised currency that charges taxes, and one that doesn't.