When the Keychat client fetches messages from Keychat relay, the relay requires the client to specify the receiving address. In other words, the client must say which receiving address it wants messages for, rather than simply asking the relay to return all kind 1059 messages from the past hour. We are not sure whether other relays enforce the same rule, but for private notes this requirement is very reasonable. We hope more relays will adopt it as well. That would make it much harder for outsiders to discover a group’s receiving address. Users can also click “Update My Group Key” from time to time. This will rotate the group’s receiving address.