Preparing for 3DES Retirement - O365 Skype for Business
Published Apr 18 2019 08:58 AM 12.3K Views


We are planning to discontinue support for 3DES in O365 Skype for Business starting on July 10, 2019.  Please refer to the following O365 Encryption guidance for 3DES retirement preparation -



The following Office 365 Skype for Business clients and devices rely on 3DES and therefore must be updated or replaced:

    • Lync for Mac 2011
    • All Lync 2010 clients
    • Lync Phone Edition

To prepare your organization for the client connectivity scenarios, you should ensure that your clients meet the following minimum versions:

  • Skype for Business Click-to-Run - Requires the April 2018 Updates:
    •  Monthly and Semi-Annual Targeted - 16.0.9126.2152 and higher
    •  Semi-Annual and Deferred Channel - 16.0.8431.2242 and higher
  • Skype for Business 2019 volume license
  • Skype for Business 2016 Desktop Client, MSI 0.4678.1000 and higher, including Basic
  • Lync 2013 (Skype for Business 2015) Desktop Client, MSI and C2R, including Basic 0.5023.1000 and higher
  • Skype for Business for Mac 16.15 and higher
  • Skype for Business for iOS and Android 6.19 and higher
  • Certified Skype for Business Online Phones -  Further guidance is located here.
Version history
Last update:
‎Apr 18 2019 04:51 PM
Updated by: