40 sats \ 5 replies \ @benthecarman 25 Oct 2023 \ parent \ on: Solving subscriptions on Bitcoin, one zap at a time bitcoin
NWC is more of a way to deliver invoices to a user's wallet, rather than prove you paid a merchant. It works great for subscriptions because you can send directly to the user without the user having to remember to pay the merchant.
Right! And I love it. I understand that it would work great. But I'm just saying there are privacy trade-offs. With NWC, a relay is incentivized to figure out all the billing addresses for one user, and then sell that list. The relay will basically have a honey-pot of a user's spending patterns. Assuming I understand the protocol correctly. Which, tbh, I haven't read it fully yet.
To simplify, NWC, has address-re-use privacy concerns, that could be reverse-engineered by a slightly ambitious relay. Have I got this part correct?
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No, relays can't interfere. These are encrypted requests.
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So the relays don't see a public key for the "billing address"?
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They just see encrypted DM's, that could be for any reason. But also, NWC dictates that a specific private/public keypair is used to communicate with the recipient. So even if they know a DM is meant for NWC (they wouldn't know), they couldn't do anything with it.
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Gotcha. I guess the relay would have to make more assumptions than I presumed, to get even crumbs of intelligence. Thanks for the taking her with me, Tony. Keep up the great work you guys are doing!
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