Patent ID: 7934096

Claim:
A method of authentication using a configured smart card with a configured client, the configured client including a trusted platform module, the method comprising: generating an integrity key that comprises a system code that uniquely identifies a state of the configured client and that is held tamperproof by the trusted platform module, wherein the integrity key is generated based on the system code and based on a storage root key that is held secret by the trusted platform module and based on a modifier, and wherein the integrity key is securely stored on the configured client; receiving, by the configured client, an encrypted modifier from the configured smart card, wherein the encrypted modifier is the modifier encrypted using the integrity key: decrypting the received encrypted modifier using the integrity key that is securely stored on the configured client; receiving, by the configured client from a user, a personal identification number; calculating a prime personal identification number based on the received personal identification number and the decrypted modifier; and unlocking the configured smart card using the calculated prime personal identification number, wherein the unlocking is based on the calculated prime personal identification number matching a previously-set prime personal identification number of the configured smart card.