keystore and certificate for BI4.1 Cluster

Dear All,

regarding the Chapter "Generate keystore and certificate for SAP BO BI4.0" on topic report below :

     http://bobi.blog.com/2014/04/12/sap-administrationhow-to-setup-sso-against-sap-bw-with-sap-bo-bi4-0-common-semantic-layer-unx-or-bics/

In a BI4.1 Cluster Do I have to make a certificate for each Server ?

And afterwards Do I have to load all these certificates in SAP BW ?

Best Regards,

MJ