Bitcoin Core's private broadcast now always opens all three connections
Serguey Asael Shinder1 min readBitcoin Core merged pull request #36277, "net: always complete all initial private broadcast connections", on 6 October. The author is andrewtoth.
The change. The patch makes sure all three connections are sent out when a private broadcast starts. When a transaction is received back or conflicts with the mempool, it is now marked as resolved (MarkResolved) instead of being removed, and the code tracks disconnects and grants new retry connections explicitly (TryGrantRetry) to prevent additional stale retries.
Why. The pull request describes itself as an alternative to an earlier proposal, #34707, and says it addresses a theoretical timing attack raised in review there, as well as other theoretical timing attacks discussed during review of #29415, the pull request that introduced private broadcast. The principle it implements is quoted from that discussion: "always send 3 times regardless if the tx is received in our mempool or is otherwise invalid."
The change is in the networking code and will reach users in a future release; the pull request does not name one.