bitcoin/doc/release-notes-29415.md

P2P and network changes

• Normally local transactions are broadcast to all connected peers with which we do transaction relay. Now, for the sendrawtransaction RPC this behavior can be changed to only do the broadcast via the Tor or I2P networks. A new boolean option -privatebroadcast has been added to enable this behavior. This improves the privacy of the transaction originator in two aspects:
  1. Their IP address (and thus geolocation) is never known to the recipients.
  2. If the originator sends two otherwise unrelated transactions, they will not be linkable. This is because a separate connection is used for broadcasting each transaction. (#29415)