Bitcoin Core 32.0 targets speed and security fixes ahead of October 10 release

Bitcoin Core 32.0, the open-source program that powers the vast majority of full nodes on the network, tagged its first release candidate on September 14 and is targeting a stable release on October 10.

The update doesn't change Bitcoin's consensus rules. Instead, it focuses on under-the-hood improvements that make running a node faster, cheaper, and less likely to get exploited by a well-crafted attack.

The headline performance improvement in v32.0 comes from a rethinking of how the software validates blocks. Bitcoin Core now fetches transaction inputs in parallel during block validation, rather than processing them sequentially. In testing, this change produced up to 3x faster initial block downloads.

Initial block download, or IBD, is the process a new node goes through to sync with the entire Bitcoin blockchain from scratch. Cutting that time by a factor of three makes it meaningfully easier for new participants to join the network.

Version 32.0 introduces a mempool-based fee estimation mechanism that supplements the historical model. The mempool is essentially the waiting room for unconfirmed transactions. By examining what's currently sitting in the mempool, the software can recommend lower fees during periods of reduced congestion.