About using a smart card with your device
Smart cards store certificates and private keys. You can use a smart card reader to import certificates from a smart card to the key store on your BlackBerry® device, but you cannot import private keys. As a result, private key operations such as signing and decryption use the smart card, and public key operations such as verification and encryption use the public certificates on your device.
If you use a smart card certificate to authenticate with your device, after you connect your smart card reader to your device, your device requests authentication from the smart card each time that you unlock your device.
You can install multiple smart card drivers on your device, including drivers for microSD smart cards, but you can only authenticate to one smart card at a time. If you are authenticating using a microSD smart card and you want to transfer media files between your microSD smart card and your computer in mass storage mode, you must temporarily turn off two-factor authentication or select a different authentication option.