Hi,

On Mon, Jun 27, 2022 at 2:14 PM Alfred Hodler via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> 2. Notification transactions still exist but no longer leave a privacy
> footprint on the blockchain. Instead, a notification transaction is simply
> a single OP_RETURN containing a value that only Alice and Bob can
> calculate. If Alice's notification transaction uses UTXOs not associated
> with her identity, there is never a footprint showing that either her or
> Bob are using private payments. If Alice uses tainted coins, only she is
> exposed as a user of Private Payments but Bob still isn't.
>

That's a neat trick. What about not using OP_RETURN at all, and just
publishing on a tor hidden service that other wallets check?  Alice
wouldn't have to expose on-chain that she is a sender of a private payment.

- Bryan
https://twitter.com/kanzure