Download the DualShield IdP Certificate 

       
         Log in to the DualShield Administration Console, Navigate to "SSO | SSO Servers".
         Select the context "..." menu of 'Single Sign-on Server' then select, "Download IdP Certificate". A CRT file will be saved to the local machine: 

Note: If the IdP Certificate is a Self-Signed certificate, then you need to import this Certificate in to the SharePoint machine account.