Deterministic payer ID based on the contact

[Zk2u]

I haven't checked features or functionality for this, but assuming based on the release notes of 2.3.4, it may be a good idea to support deterministic payer ID/key for each contact.

This way, contacts can attribute payments from the same person but payments cannot be correlated between senders. This is how, for example, MAC addresses for Apple's Private Network Addresses work, where the phone will use a persistent MAC for a given network.

I advise this is the default as it's a good balance between privacy and usability, but the other two options should still be available.

Thanks for an awesome project!

[dpad85]

That's a good idea. There are several options, like using a mix of the user's payer key + a static element of the payee's offer to build this deterministic payer key. Or an attribute from the device.

We're still iterating so I think we can try a few things and maybe make a BLIP eventually.

[t-bast]

Thanks for the suggestion, I started drafting something like this in https://github.com/lightning/blips/pull/42