This policy setting allows you to manage the reading of all certificates from the smart card for logon.
During logon Windows will by default only read the default certificate from the smart card unless it supports retrieval of all certificates in a single call. This setting forces Windows to read all the certificates from the card. This can introduce a significant performance decrease in certain situations. Please contact your smart card vendor to determine if your smart card and associated CSP supports the required behavior.
If you enable this setting, then Windows will attempt to read all certificates from the smart card regardless of the feature set of the CSP.
If you disable or do not configure this setting, Windows will only attempt to read the default certificate from those cards that do not support retrieval of all certificates in a single call. Certificates other than the default will not be available for logon.