According to one embodiment, a method for delivering a mating key to a smart card coupled to a decoding device with a built-in descrambler. The mating key is used by the smart card to encrypt the derived descrambling key for the specific decoder with descrambler. The corresponding mating key is a derivation calculated within the descrambler circuit using a unique value stored in the decoding device, and is of a message that comprises a unique predetermined value that identifies a manufacturer of the decoding device, the digital device targeted to receive the encrypted key data, and the service provider.