RSA (smartcard algorithm) and BK (boxkey)

each smartcard and set-top box has got an unique rsa and bk
that's the reason that smarcard can't be readed by other set-top box or external reader
also mean your smartcard and set-top box can be easily reconized because of unique rsa and bk between the two devices

recently most of satellite providers implemented rsa and bk

sky it
rsabksdk.JPG
if the screen displays "Smart Card not associated" or "Smart Card recognition in progress"? Notice 07, you are not enabled to view due to the missing association of your Smart Card with the Sky decoder in use. Take note of the STB ID code, view a video within the message and continue with the next steps to make the association.

telekom rom
RSA.jpg


here is an example of rsa bk keys
keyrsabk.jpg