SAML - Multiple Signing Keys

Are you talking about having multiple SAMLs ??

You can have multiple configs for 'SAML Authentication Handler' here /system/console/configMgr 

Multiple signing keys from the same IDP.  I don't think it's a SAML configuration issue as much as it a back end capability to accept multiple signing keys from the same IDP.

From our Security Engineering Group

Here is the basic flow:

1.   Receive SAML Token signed with Certificate X
2.   Does Certificate 1, registered within the Adobe application, match Certificate X?
   1.   If yes, use Certificate 1 to validate the signature of the SAML Token
   2.   If no, does Certificate 2, registered within the Adobe application, match Certificate X?
      1.                            If yes, use Certificate 2 to validate the signature of the SAML Token
      2.                          If no, failure

Additionally, once a certificate is found, it could be flagged for some session period to become the default certificate for validation purposes which would help eliminate the need to perform the IF-ELSE checks each time.

Thanks for details. We store idpCertAlias as string & need to change to array to match your need. Sounds doable, can you please file a support request to track this enhancement?