Why not allow the user create currency ex nihilo like how Central Banks do it.  That way the currency is worthless and people would only create it temporarily in order to engage in trade

Lets say I've got pies that I wanna trade for socks.  But the sock guy don't need pies.  But lets say there is an electronic exchange w order books w people with things to trade for something else.  The exchange would match up all the trades necessary for all transactions to come full circle.  Each trader generates some amount of currency (credit for their goods) then the exchange looks for trades to match up the orders.  Then the orders are executed all at once and each user ends up with a coupon for what they need and gives a coupon redeemable for exchange of hard goods.  In essence each user is issuing currency but only redeemable in assets that they can back.  So I issue my pie note convertible for 1 pie.  Sock guy issues sock note convertible to 1 pair of socks.  The exchange has to find all the orders so that there is no excess currency in the system.  All balance sheets close to zero after the orders are complete.

The currency itself is ephemeral and not worth anything.  No value ever so only the backing asset has intrinsic value.

I'm just toying w the idea conceptually as a mental exercise.  Probably in practice it would require too much energy compared to centrally controlled currency