I really like this idea, Martin! It’s a lot like Ryan Fugger’s original Ripple concept, with its focus on user-issued tokens and lines of trust between users. At the end of the day, money has value because people believe it does. Bitcoin and other cryptos have demonstrated that this belief isn’t reliant on physical trappings like a gold standard or government backing. But the wealth distributions of Bitcoin & Co. are horrible — they have far heavier tails than fiat wealth distributions. So why not issue tokens to everybody?

The main question I have is about Sybil attacks. Is being in a Circle with someone else transitive? What I mean is, say I’ve got 10 people that trust me (have me within their Circle, so that my currency and theirs’ are fungible) and I issue 1 Jackcoin per hour. I create 100 new accounts, and they all trust the Jack account, and vice-versa. I guess the new accounts’ currencies are permanently stamped with the new accounts’ names (and not “Jack”), so even if they were funneled through the Jack account, the new coins would not be fungible with the 10 other users’ currencies. (This requires users to pay an awful lot of attention to not just who they’re trusting, but to their next-nearest-neighbors as well.)

Anyway, I think the details may need some tweaking — as I understand it, one takeaway from the old Ripple model is that the concept of “trust lines” was just too complicated, and users didn’t really understand or use it — but the basic concept is very cool.