---
# This file is licensed under the MIT License (MIT) available on
# http://opensource.org/licenses/MIT.
# Text originally from Bitcoin Core project
# Metadata and small formatting changes from Bitcoin.org project

## Please see _releases/0.10.0.md for a release template
required_version: 0.6.3
optional_date: 2012-06-25
title: Bitcoin-Qt version 0.6.3 released
---
Bitcoin-Qt version 0.6.3 is now available for download at:
  <http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.6.3/>

This is a bug-fix release, with no new features.

CHANGE SUMMARY
==============

Fixed a serious denial-of-service attack that could cause the
bitcoin process to become unresponsive. Thanks to Sergio Lerner
for finding and responsibly reporting the problem. (CVE-2012-3789)

Optimized the process of checking transaction signatures, to
speed up processing of new block messages and make propagating
blocks across the network faster.

Fixed an obscure bug that could cause the bitcoin process to get
stuck on an invalid block-chain, if the invalid chain was
hundreds of blocks long.

Bitcoin-Qt no longer automatically selects the first address
in the address book (Issue #1384).

Fixed minimize-to-dock behavior of Bitcon-Qt on the Mac.

Added a block checkpoint at block 185,333 to speed up initial
blockchain download.


Thanks to everybody who contributed to this release:
====================================================

- Chris Moore
- Christian von Roques
- Fordy
- Gavin Andresen
- Jeff Garzik
- Luke Dashjr
- Matt Corallo
- Michael Hendricks
- Peter Todd
- Philip Kaufmann
- Pieter Wuille
- R E Broadley
- Sergio Lerner
- Wladimir J. van der Laan
