Receive private payments from anyone on a single static address without requiring any interaction or extra on-chain overhead.
The recipient generates a so-called silent payment address and makes it publicly known. The sender then takes a public key from one of their chosen inputs for the payment, and uses it to derive a shared secret that is then used to tweak the silent payment address. The recipient detects the payment by scanning every transaction in the blockchain.
Compared to previous schemes[^1], this scheme avoids using the Bitcoin blockchain as a messaging layer[^2] and requires no interaction between sender and recipient[^3] (other than needing to know the silent payment address). The main downsides are the scanning requirement, the lack of light client support, and the requirement to control your own input(s). An example use case would be private one-time donations.