What are silent payments (BIP-352)?
A reusable payment code. Each sender works out a fresh address from it, so two payments to the same code cannot be linked on chain.
Publishing an address usually means reuse: everyone can watch what arrives at it. A silent-payment code instead lets each sender combine it with their own payment's data to derive a one-off address, which only the receiver can recognise and spend from.
The receiver must scan the chain to notice payments, which costs more work than an ordinary wallet check. BIP-352 is finished and ready to adopt, but each wallet chooses whether to support it; sending to a code needs one that does.
References
- Bitcoin Improvement Proposals, “BIP-352: Silent Payments”.