Patent ID: 7849326

Claim:
A data processing system comprising: a removable hardware device including: means for storing a private key of a first asymmetric cryptographic key pair and a public key of a second asymmetric cryptographic key pair; a first hardware interface for electrically engaging a system unit; and means for authenticating a hardware security unit; a system unit including: a second hardware interface for electrically engaging the removable hardware device; a hardware security unit including: means for storing a private key of the second asymmetric cryptographic key pair and a public key of the first asymmetric cryptographic key pair; means for authenticating the removable hardware device; and means for enabling the system unit to invoke cryptographic functions on the hardware security unit while the removable hardware device remains electrically engaged with the system unit after the removable hardware device and the hardware security unit have been mutually authenticated; means for executing a software security unit on the system unit, wherein the software security unit contains a private key of a third asymmetric cryptographic key pair and a public key of a fourth asymmetric cryptographic key pair, and wherein the hardware security unit contains a private key of the fourth asymmetric cryptographic key pair and a public key of the third asymmetric cryptographic key pair; means for performing a mutual authentication operation between the software security unit and the hardware security unit; means for enabling the software security unit to invoke functions on the hardware security unit while the removable hardware device remains electrically engaged with the system unit in response to successfully performing the mutual authentication operation between the software security unit and the hardware security unit; and means for generating a digital certificate for the software security unit by the hardware security unit in response to a request from the software security unit while the removable hardware device remains electrically engaged with the system unit.