If wallets implement this, it is nearly unstoppable. The event stores the money itself! It only redeemable by the owner of the public key. But there is a lock time condition, as well: if the owner doesn’t claim the ecash, you can refund to yourself after a time. All of this happens without touchi...

That's sounds cool, the question is do they all use the same mint? Trusting a mint, is the issue. Do you see clients establishing some sort of federation?

It took a bit to build but now all the pieces are there in the protocol: - P2PK that allows you to mint ecash that only the owner of an npub can spend [1] - DLEQ proofs that allow *anyone* to check if the ecash that is publicly posted is signed by the mint public keys [2] With this, we could do ...

Sounds overly complicated and such requirement would likely kill zaps.