Private Octopus Inc. DNS-SD (DNS Service Discovery) normally discloses information about both the devices offering services and the devices requesting services. This information includes host names, network parameters, and possibly a further description of the corresponding service instance. Especially when mobile devices engage in DNS Service Discovery over Multicast DNS at a public hotspot, a serious privacy problem arises. The draft currently progressing in the DNS-SD Working Group assumes peer-to-peer pairing between the service to be discovered and each of its clients. This has good security properties, but creates scaling issues, because each server needs to publish as many announcements as it has paired clients. This leads to large number of operations when servers are paired with many clients. Different designs are possible. For example, if there was only one server "discovery key" known by each authorized client, each server would only have to announce a single record, and clients would only have to process one response for each server that is present on the network. Yet, these designs will present different privacy profiles, and pose different management challenges. This draft analyses the tradeoffs between privacy and scaling in a set of different designs, using either shared secrets or public keys.