You could solve this with a universal basic income like Friedrich Hayek and Milton Friedman have suggested [...] So what you need is a population register with people who qualify for UBI (citizens or similar).
This video explains a method to run a UBI program on a blockchain. I think it is a good start. Looks like UBI could be decentralized and you may not have to track citizens in the way that you might expect.
You can probably skip the first 15 min .. also, Youtube lets you speed up videos, you'll have to pop it out of the comment so it loads at youtube.com then under the settings gear icon try 1.5x speed ..