Bitcoin Core’s privacy fix reaches v32 code while the v31 patch remains open

Introduction

Bitcoin Core has merged a privacy fix into its 32.x source branch addressing behavior that could correlate private-broadcast connections with ordinary node connections.

Current State

The backport for 31.x remains open as of Oct. 8, leaving users who enable the feature on the latest stable release, 31.1, awaiting the repair. Private broadcast is disabled by default.

Background

The Oct. 1 backport includes the original change, which reached the main development branch on Sept. 25. A separate proposal to bring the fix to 31.x received an approval from reviewer vasild on Oct. 6 and carries a 31.2 milestone.

Impact

Users enable the privatebroadcast option for submissions through sendrawtransaction, the command for sending a raw transaction to the network. This path uses dedicated, short-lived connections to Tor or I2P peers, or to IPv4 and IPv6 peers through Tor.

Concerns

The connection-linking concern applies to this private-broadcast activity, rather than every node running the default configuration. The problem involves “discouragement,” Bitcoin Core’s handling of certain misbehaving peers, the other nodes it connects to.

Solution

The patch separates those behaviors. Private-broadcast peers are excluded from normal discouragement handling, while misbehaving private peers are still disconnected. Conversely, discouraging an ordinary peer no longer disconnects private-broadcast connections sharing its address.

Related Reading

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