Anonymous multiparty transfer

It would be nice if there was some Monero like functionality where A can send B some cash. Right now, that would be: A swaps into TORN, on another day A redeems with B’s receiver address. However, A would have to leave its deposit in the Pool for a while, to increase anonymity - there would be no instant settlement. Also, A could send the note to B, but B would have no guarantee that A doesn’t spend the note - that would be no settlement.

The leanest approach would be a functionality of a note, which can be restricted to be only be redeemed by a specified address. A would generate this note with Bs address and after the deposit send the note to B. B could verify that the deposit is in TORN and nobody but B could spend the note. This would be a two-party anonymous transfer with instant settlement.

The next feature then would be B creating a new note, restricted to C’s address, but instead of depositing some ETH, B can redeem the note he got by A.

Because in that case B uses tornado cash without adding to its anonymity set, a protocol fee could be required from B (anonymous transfer fee).

This is the direction tornado cash is moving towards. A year ago there was already a prototype repo of tornado pool that allows arbitrary deposit/withdraw amounts and can do split/join transactions (2 input / 2 output) inside the pool. And it was even cheaper on chain than the current version. Obviously since then there was some progress in this direction.

Sounds great. Is there some repository we could look at?

I think this may be the repo.