Request for Proposals: Note Discovery Protocol

[Anon]

[Proposal] View Tag Batch PIR

A note discovery protocol. Notes expose a 16-bit view-tag H(shared_secret || offset)[:2] ([1], [2], [3]), over which batch PIR [4] queries are made, reducing sync bandwidth of notes by up to 98%. Details tx = { ephemeral_pk, notes: [{view_tag, ciphertext}, ..] } view_tag = H(dh_shared_secret || offset)[:2] offset increments for repeated shared_secrets. e.g. if a tx sends 3 notes to 2 addresses, the view-tags would be H(secret_1 || 0), H(secret_1 || 1), H(secret_2 || 0). To ensure no pri…