Published: May 12, 2015 | Updated: October 13, 2015
On May 12, 2015, Microsoft announced the availability of an update to cryptographic cipher suite prioritization in Windows 7, Windows Server 2008 R2, Windows 8, Windows Server 2012, Windows 8.1, and Windows Server 2012 R2. The update added additional cipher suites to the default list on affected systems and improved cipher suite priority ordering. The improvements were in keeping with ongoing efforts to bolster the effectiveness of encryption in Windows operating systems.
Microsoft initially offered the update via the Microsoft Download Center (DLC) only in order to give customers the opportunity to test the new features before making them a default part of their environments.
Windows Server 2008 R2 for x64-based Systems Service Pack 1
Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
Windows 8 for 32-bit Systems
Windows 8 for x64-based Systems
Windows Server 2012
Windows 8.1 for 32-bit Systems
Windows 8.1 for x64-based Systems
Windows Server 2012 R2
Server Core installation option
Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
Windows Server 2012 (Server Core installation)
Windows Server 2012 R2 (Server Core installation)
**What is the scope of the advisory?**
The purpose of this advisory is to notify customers of an available update that is part of Microsoft’s ongoing efforts to bolster the effectiveness of security controls in Windows.
**What does the update do?**
The update adds the following cryptographic cipher suites to the default list in all affected operating systems and includes improvements to the cipher suite priority ordering.
Cipher Suites Added by the Update
**What do these cipher suites do?**
The cipher suites add support for Perfect Forward Secrecy (PFS). While providing enhanced security, PFS could have a noticeable effect on system performance in some scenarios due to its higher computing requirements. For more information, see [Microsoft Knowledge Base Article 3042058](http://support.microsoft.com/kb/3042058).
**What internal testing should be done with respect to this update?**
Any applications, including Internet Explorer, IIS, SQL Server, or Exchange Server, that use Schannel to implement or negotiate SSL/TLS connections should be tested thoroughly. Especially scenarios where a large number of simultaneous connections are made, such as with web or database servers that host many users, or edge servers that handle many secure connections and forward them to internal servers. All existing SSL/TLS applications should behave as expected. Note that although the new cipher suites are more secure, they are likely to be more resource intensive. Therefore, customers should test for an increase in resource consumption when the number of SSL/TLS connections scales up (in both server and client scenarios).
- You can provide feedback by completing the Microsoft Help and Support form, [Customer Service Contact Us](http://support.microsoft.com/kb/?scid=sw;en;1257&showpage=1&ws=technet&sd=tech).
- Customers in the United States and Canada can receive technical support from [Security Support](http://go.microsoft.com/fwlink/?linkid=21131). For more information, see [Microsoft Help and Support](http://support.microsoft.com/).
- International customers can receive support from their local Microsoft subsidiaries. For more information, see [International Support](http://go.microsoft.com/fwlink/?linkid=21155).
- [Microsoft TechNet Security](http://go.microsoft.com/fwlink/?linkid=21132) provides additional information about security in Microsoft products.
The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
- V1.0 (May 12, 2015): Advisory published.
- V1.1 (October 13, 2015): Advisory revised to announce that the Default Cipher Suite Prioritization update (3042058), originally released May 12, 2015 via the Microsoft Download Center (DLC) only, is now also available via Microsoft Update (MU) and Windows Server Update Services (WSUS). This is an update offering venue change only. There were no changes to the update files. Customers who have already successfully installed the update do not need to take any action.
*Page generated 2015-10-07 11:07-07:00.*