Microsoft Smart Card Minidriver


Microsoft has introduced a new interface for smart card vendors to support smart card for Microsoft CryptoAPI, called Smart Card Minidriver. Microsoft has introduced a new CSP with name Microsoft Smart Card Base CSP which will support these minidrivers.

More information about the standard can be obtained from Microsoft Developer Network


Currently the product supports Smart Card Minidriver version 5.0 and 6.0, but not version 7.0. The reason for not supporting 7.0 is that there are no implementations available which use the new functions introduced with 7.0. The new version was introduced for a card management product from Microsoft, with unknown release date.

Application usage

An application using CryptoAPI with certificates from user certificate store will not need to do anything. An application concerned with the CSP used will need to use the name "Microsoft Smart Card Base CSP" instead of the name "Net iD – CSP".

Known limitations

When comparing CSP with Minidriver there are currently two known limitations with Minidriver: no support for secondary/role certificates and pin pad.

The first limitation, no support for secondary certificates, is really for unknown reasons. Ask Microsoft for more information about why Microsoft Smart Card Base CSP cannot handle multiple certificates for the same private key.

The second limitation, no support for pin pad, will probably be solved in the future by Microsoft Smart Card Base CSP, since part of the minidriver specification is not supported today.


The real difference between our CSP and Minidriver is the dialogs. Our CSP will show our dialogs and Microsoft Smart Card Base CSP working with our Minidriver will show Microsoft dialogs, our Minidriver will not show any dialogs.