Bitcoin Core Integrates Fix for Privacy Flaw in Sender-Anonymity Feature into Upcoming 32.x Series; Current 31.x Remains Unpatched

Bitcoin Core's development team has fixed a privacy flaw inherent in an experimental feature designed to conceal the origin of transactions on the Bitcoin (BTC) network. The fix has been integrated into the code for the upcoming 32.x series, while backporting to the current stable 31.x series remains incomplete, creating a disparity in remediation status between the two version lines.

According to development records on GitHub, the fix was merged on October 1. The target was an optional feature called "Private Broadcast," introduced experimentally in version 31.0. It is disabled by default and only operates when a user explicitly enables it.

The feature aims to make it harder for outside parties to identify the sender's IP address. Normally, Bitcoin transactions are broadcast through persistent connections between nodes, but Private Broadcast employs short-lived dedicated connections routed through anonymity networks such as Tor and I2P to transmit raw transactions.

The problem identified concerned the scope of discouragement penalties applied to misbehaving peer nodes. In the previous implementation, these dedicated connections were subject to the same discouragement measures as regular connections.