Key protection device for smart cards

摘要

This invention concerns a key protection device for smart cards and is characterized by the fact that: each input user key is coded using a random key and stored; protection data that corresponds to each coded user key's dependant data is generated and associated to each coded user key; a detection device is installed on the card that allows the user to verify the stored user key's integrity by comparing the protection data to verification data that is generated using the card's stored user key; and an interlock device that allows the user to block any further calculation using the stored key in the event that the verification data is not identical to the protection data.