Microsoft Message Queuing (MSMQ) - SHA 2 Is the Default Hash Algorithm

Affected Platforms

Clients - Windows XP | Windows Vista | Windows 7
Servers - Windows Server 2003 | Windows Server 2008 | Windows Server 2008 R2

Feature Impact

Severity - Low
Frequency - Low


In Windows 7, MSMQ uses SHA-2 as the default when signing an outgoing message. Additionally, all incoming messages must be signed with SHA-2. You can enable support for a lower encryption algorithm through an administrator-accessible registry key.

Manifestation of Impact

  • MSMQ in Windows 2003 or below will not accept signed messages originating from MSMQ in Windows 7
  • MSMQ in Windows 7 will not accept signed messages originating from Windows 2008 or below


Users should consider upgrading to Windows 7 to leverage the stronger signing algorithm. To enable seamless signed message exchange between Windows 7 and any down-level operating system, the Administrator must add appropriate exceptions on the MSMQ machines.