Bitcoin Blockchain Initial Sync Time Dramatically Reduced By Headers-First Sync

Caleb Chen @bitxbitxbitcoin
October 18, 2014

Downloading the Bitcoin blockchain is about to become a lot easier, ending a common complaint that users have about the barrier of entry to using Bitcoin software. With this new feature, new users can be fully synced with Bitcoin Core closer to 4 hours, as opposed to 2 days on an average internet connection. The common complaint about Bitcoin is that the start-up time in getting set up with the original BitcoinQT client.Previously, in order to run a full node, the Bitcoin client requires a complete copy of the Bitcoin blockchain (22 GB at the time of writing). One bootstrap solution has been to torrent the Bitcoin blockchain data separately as it usually downloads faster that way.

Also read: Bitcoin In Bloom: How IBLTs Allow Bitcoin to Scale

Jeff Garzik first reached out to the Bitcoin community several days ago to call for review and testing. Developer Pieter Wuille explained why this implementation was so long in the making, despite having been on the backburner for years, on SourceForge:

Historically, this mode of operation has been known for years (Greg Maxwell wrote up a description of a very similar method in in early 2012, but it was known before that), but it took a long time to refactor these code enough to support it…So, the code is available as a github pull request (, or packaged on, where you can also find binaries to test with.

Bitcoin Blockchain Changes

Other potential future changes include CHECKLOCKTIMEVERIFY, presented by Peter Todd a few weeks ago, and Invertible Bloom Lookup Tables, proposed by Gavin Andresen. With this newest update, which will be pushed out in Bitcoin Core version 0.10, running a Bitcoin node will become a lot less cumbersome. Eventually, some hope, it will even be possible to run a full Bitcoin node on a mobile device, the way that one can use an android device to earn Bitcoins while supporting the Tor network. For now, though, a Raspberry Pi will have to do.

What do you think about this new development? Comment below!

Images from Shutterstock.

Last modified (UTC): October 18, 2014 05:07

Caleb Chen @bitxbitxbitcoin

Caleb is a graduate of the University of Virginia where he studied Economics, East Asian Studies, and Mathematics. He is currently pursuing his MSc in Digital Currency at the University of Nicosia.