Published on: 2022-08-01T11:38:29+00:00
In response to feedback from Ruben Somsen, Alfred Hodler has made several updates to his proposal for a new BIP that aims to enhance the privacy and future-proofing of two-party transactions. Ruben pointed out that the proposal introduces a scanning requirement to detect incoming notifications, which complicates light client implementation. He recommended that Alfred include this information in the BIP to ensure readers are aware of this downside.Ruben also noted that Alfred's proposal is similar to the BIP47 protocol improvement suggestions made in Prague, with the only difference being the addition of an extra ECDH calculation to hide the recipient payment code. This additional step leads to the scanning requirement, but allows users to broadcast notifications themselves instead of outsourcing them. Ruben suggested acknowledging this similarity and giving credit to the participants of the Prague discussion.Furthermore, Ruben advised Alfred to revisit the "Allowing collisions" paragraph from the Prague discussion, as it has the potential to reduce the size by up to 28 bytes. Despite these concerns, Ruben expressed support for Alfred's proposal and appreciated the effort put into working out details such as address formats.Alfred has taken Ruben's feedback into consideration and implemented some changes. He has incorporated Ruben's suggestion of using only the first four bytes of the notification code, as well as added Ruben as a co-author. Alfred explained that hiding the recipient in the notification not only allows Alice to send a notification herself, but also breaks the link between the notifier and Bob. This avoids social graph building issues and unique per-recipient notification addresses found in BIP47.However, light clients will need to rely on an OP_RETURN indexing service, which Alfred considers an acceptable inconvenience. This reliance reduces social metadata on the blockchain, prevents censorship of certain recipients by notification services, allows wallets to choose their level of outsourcing, and protects against attacks from adversaries monitoring notifications.Overall, Alfred's proposed BIP aims to enhance the privacy and future-proofing of two-party transactions. It builds upon the BIP47 protocol and offers increased privacy features. The proposal can be found on GitHub, and Alfred is seeking feedback to further refine it before it can be assigned a BIP number. Once the BIP is deemed viable, a reference implementation will be published.
Updated on: 2023-08-02T07:14:07.713900+00:00