Method and apparatus for communicating securely with a token

#The Trusted Platform Computing Alliance (TPCA) in the TPCA's Main Specification, Version 1.1a, dated Dec. 1, 2001 describes a Trusted Platform Module (TPM) or token that provides increased confidence and that enables enhancements of existing services and new services. The token supports auditing and logging of software processes, platform boot integrity, file integrity, and software licensing. The token provides a protected information store for the platform (e.g., a personal computer), and can be used to attest to the identity of the platform as defined by the hardware that is present (e.g. processors, chipsets, firmware, etc.) on the platform. The secure features of the token encourage third parties to grant the platform access to information that would otherwise be denied.

#The token contains an isolated computing engine whose processes can be trusted because they cannot be altered. These processes and the binding of the subsystem to the platform combine to reliably measure and report the state of the main computing environment inside the platform. The token provides a root of trust for the booting of the platform. A local or remote entity may query the token to reliably obtain security information and decide whether the platform's behavior enables it to be trusted for the intended purpose. Confidence in the loading of software is improved, because the token can attest to the current state of the operating system.

#The token may include several registers, that may be used to store encrypted digests of files, including software programs, which may be retrieved and authenticated. Information written to and read from the token is to be secure in order for third parties to trust the platform. The mapping of the registers as traditional Input/Output (I/O) mapped registers is undesirable as a device on the same interface as the token may be programmed to map to the same I/O addresses, thereby compromising the security of the token.

#One or more embodiments of the present invention described herein are illustrated by way of example and not by way of limitation in the accompanying figures. For simplicity and clarity of illustration, elements illustrated in the figures are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.

#FIG. 1 illustrates a computing device comprising a token according to one embodiment of the invention.

#FIG. 2 illustrates a flow diagram for communicating with a token according to one embodiment of the invention.

#Described is a method and apparatus for communicating securely with a token. In the following description, numerous specific details such as communication protocols, types and interrelationships of system components etc. are set forth in order to provide a thorough understanding of the one or more embodiments of the present invention. It will be apparent, however, to one of ordinary skill in the art that the one or more embodiments of the present invention may be practiced without these specific details. In other instances, well-known architectures, control structures, gate level circuits and full software instruction sequences and techniques have not been shown to avoid unnecessarily obscuring this description. Those of ordinary skill in the art, with the included description, will be able to implement appropriate functionality without undue experimentation.

#References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

#In the following description and claims, the terms “coupled” and “connected”, along with derivatives such as “communicatively coupled” may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other.