[Am-info] United States Patent: 6,330,670

[Geoffrey]

 From what I've read of this, it would seem to be a software solution, 
not hardware.  It all talks of an OS, not a CPU.

Martin Sandberg wrote:
> I've edited this down some, but the whole thing is at:
> 
> http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='6330670'.WKU.&OS=PN/6330670&RS=PN/6330670
> 
> 
> The key thing is that M$ is proposing a CPU with  a private key inside it that won't boot an "Untrusted" OS, I.E. an open-source OS. This is the most blatent thing I've seen yet to kill Linux.
>  
> 
> 	United States Patent	 6,330,670 England ,   et al. December 11, 2001
> 
> Digital rights management operating system
> 
> Abstract
> 
> A digital rights management operating system protects rights-managed data, such as downloaded content, from access by untrusted programs while the data is loaded into memory or on a page file as a result of the execution of a trusted application that accesses the memory. To protect the rights-managed data resident in memory, the digital rights management operating system refuses to load an untrusted program into memory while the trusted application is executing or removes the data from memory before loading the untrusted program. If the untrusted program executes at the operating system level, such as a debugger, the digital rights management operating system renounces a trusted identity created for it by the computer processor when the computer was booted. To protect the rights-managed data on the page file, the digital rights management operating system prohibits raw access to the page file, or erases the data from the page file before allowing such access. Alternatively,
 the digital rights management operating system can encrypt the rights-managed data prior to writing it to the page file. The digital rights management operating system also limits the functions the user can perform on the rights-managed data and the trusted application, and can provide a trusted clock used in place of the standard computer clock.
> 
> 
> Inventors: England; Paul (Bellevue, WA); DeTreville; John D. (Seattle, WA); Lampson; Butler W. (Cambridge, MA) Assignee: Microsoft Corporation (Redmond, WA) Appl. No.: 227561 Filed: January 8, 1999
> 
> Current U.S. Class: 713/2; 713/200 Intern'l Class: G06F 009/44 Field of Search: 713/1,2,155,164-167,200 717/11
> 
> References Cited <http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-adv.htm&r=0&f=S&l=50&d=CR01&Query=ref/6,330,670>[Referenced By]
> 
> U.S. Patent Documents
> <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F4827508>4827508May., 1989Shear. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F4969189>4969189Nov., 1990Ohta et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F4977594>4977594Dec., 1990Shear. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5050213>5050213Sep., 1991Shear. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5140634>5140634Aug., 1992Guillou et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fneta
html%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5276311>5276311Jan., 1994Hennige. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5410598>5410598Apr., 1995Shear. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5473690>5473690Dec., 1995Grimonprez et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5473692>5473692Dec., 1995Davis. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5544246>5544246Aug., 1996Mandelbaum et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5654
746>5654746Aug., 1997McMullan, Jr. et al. <http://patft.uspto.gov/neta
> rser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5721781>5721781Feb., 1998Deo et al.380/25. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5796824>5796824Aug., 1998Hasebe et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5812662>5812662Sep., 1998Hsu et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5812980>5812980Sep., 1998Asai. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5892900>5892900Apr., 1999Ginter. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f
=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5910987>5910987Jun., 1999Ginter et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5915019>5915019Jun., 1999Ginter et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5917912>5917912Jun., 1999Ginter et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5920861>5920861Jul., 1999Hall et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5933498>5933498Aug., 1999Schneck et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5940504>5940504Aug., 19
99Griswold. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect
> =PALL&RefSrch=yes&Query=PN%2F5943422>5943422Aug., 1999Van Wie et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5949876>5949876Sep., 1999Ginter et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5953502>5953502Sep., 1999Helbig, Sr. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5982891>5982891Nov., 1999Ginter et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5991876>5991876Nov., 1999Johnson et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6006332>6006332Dec., 1999Rabn
e et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6009274>6009274Dec., 1999Fletcher et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6009401>6009401Dec., 1999Horstmann. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6073124>6073124Jun., 2000Krishnan et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6112181>6112181Aug., 2000Shear et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6138119>6138119Oct., 2000Hall et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1
&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL
> ttp://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6157721>6157721Dec., 2000Shear et al. <http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6185683>6185683Feb., 2001Ginter et al.
> 
> Primary Examiner: Heckler; Thomas M.
> Attorney, Agent or Firm: Lee & Hayes, PLLC
> 
> Parent Case Text
> 
> 
> 
> RELATED APPLICATIONS
> 
> This application is a continuation-in-part of U.S. provisional patent application Ser. No. 60/105,891 filed on Oct. 26, 1998, which is herein incorporated by reference, and is related to co-pending and co-filed applications titled "System and Method for Authenticating an Operating System to a Central Processing Unit, Providing the CPU/OS with Secure Storage, and Authenticating the CPU/OS to a Third Party" Ser. No. 09/266,207, filed on Mar. 10, 1999, "Loading and Identifying a Digital Rights Management Operating System" Ser. No. 09/227,611, filed on Jan. 8, 1999, "Key-based Secure Storage" Ser. No. 09/227,568, filed Jan. 8, 1999, and "Digital Rights Management Using One Or More Access Prediates, Rights Manager Certificates, And Licenses" Ser. No. 09/227,559. filed Jan. 8, 1999.
> 
> Claims
> 
> 
> 
> Stripped out too many claims!
> 
> Description
> 
> 
> 
> FIELD OF THE INVENTION
> 
> This invention relates generally to computer operating systems, and more particularly to booting and identifying an operating system that enforces digital rights.
> 
> COPYRIGHT NOTICE/PERMISSION
> 
> A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. The following notice applies to the software and data as described below and in the drawings hereto: Copyright.COPYRGT. 1998, Microsoft Corporation, All Rights Reserved.
> 
> BACKGROUND OF THE INVENTION
> 
> More and more content is being delivered in digital form, and more and more digital content is being delivered online over private and public networks, such as Intranets, the Internet and cable TV networks. For a client, digital form allows more sophisticated content, while online delivery improves timeliness and convenience. For a publisher, digital content also reduces delivery costs. Unfortunately, these worthwhile attributes are often outweighed in the minds of publishers by the corresponding disadvantage that online information delivery makes it relatively easy to obtain pristine digital content and to pirate the content at the expense and harm of the publisher.
> 
> Piracy of digital content, especially online digital content, is not yet a great problem. Most premium content that is available on the Web is of low value, and therefore casual and organized pirates do not yet see an attractive business stealing and reselling content. Increasingly, though, higher-value content is becoming available. Books and audio recordings are available now, and as bandwidths increase, video content will start to appear. With the increase in value of online digital content, the attractiveness of organized and casual theft increases.
> 
> The unusual property of digital content is that the publisher (or reseller) gives or sells the content to a client, but continues to restrict rights to use the content even after the content is under the sole physical control of the client. For instance, a publisher will typically retain copyright to a work so that the client cannot reproduce or publish the work without permission. A publisher could also adjust pricing according to whether the client is allowed to make a persistent copy, or is just allowed to view the content online as it is delivered. These scenarios reveal a peculiar arrangement. The user that possesses the digital bits often does not have full rights to their use; instead, the provider retains at least some of the rights. In a very real sense, the legitimate user of a computer can be an adversary of the data or content provider. "Digital rights management" is therefore fast becoming a central requirement if online commerce is to continue its rapid growth
. Content providers and the computer industry must quickly provide technologies and protocols for ensuring that digital content is properly handled in accordance with the rights granted by the publisher. If measures are not taken, traditional content providers may be put out of business by widespread theft, or, more likely, will refuse altogether to deliver content online.
> 
> Traditional security systems ill serve this problem. There are highly secure schemes for encrypting data on networks, authenticating users, revoking certificates, and storing data securely. Unfortunately, none of these systems address the assurance of content security after it has been delivered to a client's machine. Traditional uses of smart cards offer little help. Smart cards merely provide authentication, storage, and encryption capabilities. Ultimately, useful content must be assembled within the host machine for display, and again, at this point the bits are subject to theft. Cryptographic coprocessors provide higher-performance cryptographic operations, and are usually programmable but again, fundamentally, any operating system or sufficiently privileged application, trusted or not, can use the services of the cryptographic processor.
> 
> There appear to be three solutions to this problem. One solution is to do away with general-purpose computing devices and use special-purpose tamper-resistant boxes for delivery, storage, and display of secure content. This is the approach adopted by the cable industry and their set-top boxes, and looks set to be the model for DVD-video presentation. The second solution is to use secret, proprietary data formats and applications software, or to use tamper-resistant software containers, in the hope that the resulting complexity will substantially impede piracy. The third solution is to modify the general-purpose computer to support a general model of client-side content security and digital rights management.
> 
> This invention is directed to a system and methodology that falls generally into the third category of solutions.
> 
> A fundamental building block for client-side content security is a secure operating system. If a computer can be booted only into an operating system that itself honors content rights, and allows only compliant applications to access rights-restricted data, then data integrity within the machine can be assured. This stepping-stone to a secure operating system is sometimes called "Secure Boot." If secure boot cannot be assured, then whatever rights management system the secure OS provides, the computer can always be booted into an insecure operating system as a step to compromise it.
> 
> Secure boot of an operating system is usually a multi-stage process. A securely booted computer runs a trusted program at startup. The trusted program loads an initial layer of the operating system and checks its integrity (by using a code signature or by other means) before allowing it to run. This layer will in turn load and check the succeeding layers. This proceeds all the way to loading trusted (signed) device drivers, and finally the trusted application(s).
> 
> An article by B. Lampson, M. Abadi, and M. Burrows, entitled "Authentication in Distributed Systems: Theory and Practice," ACM Transactions on Computer Systems v10, 265, 1992, describes in general terms the requirements for securely booting an operating system. The only hardware assist is a register that holds a machine secret. When boot begins this register becomes readable, and there's a hardware operation to make this secret unreadable. Once it's unreadable, it stays unreadable until the next boot. The boot code mints a public-key pair and a certificate that the operating system can use to authenticate itself to other parties in order to establish trust. We note that in this scheme, a malicious user can easily subvert security by replacing the boot code.
> 
> Clark and Hoffman's BITS system is designed to support secure boot from a smart card. P. C. Clark and L. J. Hoffman, "BITS: A Smartcard Operating System," Comm. ACM. 37, 66, 1994. In their design, the smart card holds the boot sector, and PCs are designed to boot from the smart card. The smart card continues to be involved in the boot process (for example, the smart card holds the signatures or keys of other parts of the OS).
> 
> Bennet Yee describes a scheme in which a secure processor first gets control of the booting machine. B. Yee, "Using Secure Coprocessors", Ph.D. Thesis, Carnegie Mellon University, 1994. The secure processor can check code integrity before loading other systems. One of the nice features of this scheme is that there is a tamper-resistant device that can later be queried for the details of the running operating system.
> 
> Another secure boot model, known as AEGIS, is disclosed by W. Arbaugh, D. G. Farber, and J. M Smith in a paper entitled "A Secure and Reliable Bootstrap Architecture", Univ. of Penn. Dept. of CIS Technical Report, IEEE Symposium on Security and Privacy, page 65, 1997. This AEGIS model requires a tamper-resistant BIOS that has hard-wired into it the signature of the following stage. This scheme has the very considerable advantage that it works well with current microprocessors and the current PC architecture, but has three drawbacks. First, the set of trusted operating systems or trusted publishers must be wired into the BIOS. Second, if the content is valuable enough (for instance, e-cash or Hollywood videos), users will find a way of replacing the BIOS with one that permits an insecure boot. Third, when obtaining data from a network server, the client has no way of proving to the remote server that it is indeed running a trusted system.
> 
> On the more general subject of client-side rights management, several systems exist or have been proposed to encapsulate data and rights in a tamper-resistant software package. An early example is IBM's Cryptolope. Another existent commercial implementation of a rights management system has been developed by Intertrust. In the audio domain, AT&T Research have proposed their "A2b" audio rights management system based on the PolicyMaker rights management system.
> 
> Therefore, there is a need in the art for a digital rights management operating system that protects the rights of the content provider while operating on a general-purpose personal computer without requiring additional hardware directed at securing downloaded content.
> 
> SUMMARY OF THE INVENTION
> 
> The above-mentioned shortcomings, disadvantages and problems are addressed by the present invention, which will be understood by reading and studying the following specification.
> 
> A digital rights management operating system protects rights-managed data, such as downloaded content, from access by untrusted programs while the data is loaded into memory or on a page file as a result of the execution of a trusted application that accesses the memory. To protect the rights-managed data resident in memory, the digital rights management operating system refuses to load an untrusted program into memory while the trusted application is executing or removes the data from memory before loading the untrusted program. In the latter instance, the digital rights management system can terminate the trusted application as well. If the untrusted program executes at the operating system level, such as a debugger, the digital rights management operating system renounces a trusted identity created for it by the computer processor when the computer was booted. To protect the rights-managed data on the page file, the digital rights management operating system prohibits ra
w access to the page file, or erases the data from the page file before allowing such access. Alternatively, the digital rights management operating system can encrypt the rights-managed data prior to writing it to the page file.
> 
> In one aspect of the invention, the digital rights management operating system also provides a trusted clock mechanism so that a user cannot reset the computer's clock to circumvent time restrictions placed on trusted components. In other aspects of the invention, the digital rights management operating system limits the functions the user can perform on the rights-managed data and the trusted application.
> 
> Thus, the digital rights management system of the present invention protects content downloaded to a general-purpose personal computer and does so within the framework of a standard operating system, alleviating the need for additional and specialized hardware.
> 
> The present invention describes systems, clients, servers, methods, and computer-readable media of varying scope. In addition to the aspects and advantages of the present invention described in this summary, further aspects and advantages of the invention will become apparent by reference to the drawings and by reading the detailed description that follows.
> 
> BRIEF DESCRIPTION OF THE DRAWINGS
> 
> FIG. 1A is a diagram of the hardware and operating environment in conjunction with which exemplary embodiments of the invention may be practiced;
> 
> FIG. 1B is a diagram of a client computer for use with exemplary embodiments of the invention;
> 
> FIG. 2 is a diagram illustrating a system-level overview of an exemplary embodiment of the invention;
> 
> FIG. 3 is a flowchart of a method to be performed by a client when booting or loading system components according to an exemplary embodiment of the invention;
> 
> FIG. 4 is a diagram of a certificate revocation list data structure for use in an exemplary implementation of the invention;
> 
> FIG. 5 is a flowchart of a method to be performed by a client to create a boot log according to an exemplary embodiment of the invention;
> 
> FIG. 6 is a block diagram of an exemplary boot log created using the method of FIG. 5;
> 
> FIGS. 7A, 7B and 7C are block diagrams of boot blocks for use in an exemplary embodiment of the invention;
> 
> FIG. 8 is a block diagram of key generation functions according to an exemplary embodiment of the invention;
> 
> FIG. 9 is a diagram of a rights manager certificate data structure for use in an exemplary implementation of the invention;
> 
> FIG. 10 is a diagram of a required properties access control list data structure for use in an exemplary implementation of the invention; and
> 
> FIG. 11 is a diagram of a license data structure for use in an exemplary implementation of the invention.
> 
> DETAILED DESCRIPTION OF THE INVENTION
> 
> In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
> 
> The detailed description is divided into four sections. In the first section, the hardware and the operating environment in conjunction with which embodiments of the invention may be practiced are described. In the second section, a system level overview of the invention is presented. The third section described methods and data structures employed by various exemplary embodiments of the invention. Finally, in the fourth section, a conclusion of the detailed description is provided.
> 
> Hardware and Operating Environment
> 
> FIG. 1A is a diagram of the hardware and operating environment in conjunction with which embodiments of the invention may be practiced. The description of FIG. 1A is intended to provide a brief, general description of suitable computer hardware and a suitable computing environment in conjunction with which the invention may be implemented. Although not required, the invention is described in the general context of computer-executable instructions, such as program modules, being executed by a computer, such as a personal computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types.
> 
> Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
> 
> The exemplary hardware and operating environment of FIG. 1A for implementing the invention includes a general purpose computing device in the form of a computer 20, including a processing unit 21, a system memory 22, and a system bus 23 that operatively couples various system components, including the system memory 22, to the processing unit 21. There may be only one or there may be more than one processing unit 21, such that the processor of computer 20 comprises a single central-processing unit (CPU), or a plurality of processing units, commonly referred to as a parallel processing environment. The computer 20 may be a conventional computer, a distributed computer, or any other type of computer; the invention is not so limited.
> 
> The system bus 23 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory may also be referred to as simply the memory, and includes read only memory (ROM) 24 and random access memory (RAM) 25. A basic input/output system (BIOS) 26, containing the basic routines that help to transfer information between elements within the computer 20, such as during start-up, is stored in ROM 24. The computer 20 further includes a hard disk drive 27 for reading from and writing to a hard disk, not shown, a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29, and an optical disk drive 30 for reading from or writing to a removable optical disk 31 such as a CD ROM or other optical media.
> 
> The hard disk drive 27, magnetic disk drive 28, and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32, a magnetic disk drive interface 33, and an optical disk drive interface 34, respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for the computer 20. It should be appreciated by those skilled in the art that any type of computer-readable media that can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs), and the like, may be used in the exemplary operating environment.
> 
> A number of program modules may be stored on the hard disk, magnetic disk 29, optical disk 31, ROM 24, or RAM 25, including an operating system 35, one or more application programs 36, other program modules 37, and program data 38. A user may enter commands and information into the personal computer 20 through input devices such as a keyboard 40 and pointing device 42. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 21 through a serial port interface 46 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port, or a universal serial bus (USB). A monitor 47 or other type of display device is also connected to the system bus 23 via an interface, such as a video adapter 48. In addition to the monitor, computers typically include other peripheral output devices (not shown), such as spea
kers and printers.
> 
> The computer 20 may operate in a networked environment using logical connections to one or more remote computers, such as remote computer 49. These logical connections are achieved by a communication device coupled to or a part of the computer 20; the invention is not limited to a particular type of communications device. The remote computer 49 may be another computer, a server, a router, a network PC, a client, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 20, although only a memory storage device 50 has been illustrated in FIG. 1. The logical connections depicted in FIG. l include a local-area network (LAN) 51 and a wide-area network (WAN) 52. Such networking environments arc commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
> 
> When used in a LAN-networking environment, the computer 20 is connected to the local network 51 through a network interface or adapter 53, which is one type of communications device. When used in a WAN-networking environment, the computer 20 typically includes a modem 54, a type of communications device, or any other type of communications device for establishing communications over the wide area network 52, such as the Internet. The modem 54, which may be internal or external, is connected to the system bus 23 via the serial port interface 46. In a networked environment, program modules depicted relative to the personal computer 20, or portions thereof, may be stored in the remote memory storage device. It is appreciated that the network connections shown are exemplary and other means of and communications devices for establishing a communications link between the computers may be used.
> 
> The hardware and operating environment in conjunction with which embodiments of the invention may be practiced has been described. The computer in conjunction with which embodiments of the invention may be practiced may be a conventional computer, a distributed computer, or any other type of computer; the invention is not so limited. Such a computer typically includes one or more processing units as its processor, and a computer-readable medium such as a memory. The computer may also include a communications device such as a network adapter or a modem, so that it is able to communicatively couple to other computers.
> 
> One exemplary embodiment of a suitable client computer is described in the related application titled "System and Method for Authenticating an Operating System to a Central Processing Unit, Providing the CPU/OS with Secure Storage, and Authenticating the CPU/OS to a Third Party," and illustrated in FIG. 1B as subscriber unit 124. The CPU 140 in the subscriber unit 124 is able to authenticate the identity of the boot block and OS components that have been loaded into the computer, and to provide quoting and secure storage operations based on this identity as briefly described next. Full descriptions of various embodiments for the subscriber unit 124 are provided in the related application.
> 
> The CPU 140 has a processor 160 and also can have a cryptographic accelerator 162. The CPU 140 is capable of performing cryptographic functions, such as signing, encrypting, decrypting, and authenticating, with or without the accelerator 162 assisting in intensive mathematical computations commonly involved in cryptographic functions.
> 
> The CPU manufacturer equips the CPU 140 with a pair of public and private keys 164 that is unique to the CPU. For discussion purpose, the CPU's public key is referred to as "K.sub.CPU " and the corresponding private key is referred to as "K.sub.CPU.sup.-1 ". Other physical implementations may include storing the key on an external device to which the main CPU has privileged access (where the stored secrets are inaccessible to arbitrary application or operating systems code). The private key is never revealed and is used only for the specific purpose of signing stylized statements, such as when responding to challenges from a content provider, as is discussed below.
> 
> The manufacturer also issues a signed certificate 166 testifying that it produced the CPU according to a known specification. Generally, the certificate testifies that the manufacturer created the key pair 164, placed the key pair onto the CPU 140, and then destroyed its own knowledge of the private key "K.sub.CPU.sup.-1 ". In this way, only the CPU knows the CPU private key K.sub.CPU.sup.-1 ; the same key is not issued to other CPUs and the manufacturer keeps no record of it. The certificate can in principle be stored on a separate physical device associated with the processor but still logically belongs to the processor with the corresponding key.
> 
> The manufacturer has a pair of public and private signing keys, K.sub.MFR and K.sub.MFR.sup.-1. The private key K.sub.MFR.sup.-1 is known only to the manufacturer, while the public key K.sub.MFR is made available to the public. The manufacturer certificate 166 contains the manufacturer's public key K.sub.MFR, the CPU's public key K.sub.CPU, and the above testimony. The manufacture signs the certificate using its private signing key, K.sub.MFR.sup.-1, as follows:
> 
> Mfr. Certificate=(K.sub.MFR, Certifies-for-Boot, K.sub.CPU), signed by K.sub.MFR.sup.-1
> 
> The predicate "certifies-for-boot" is a pledge by the manufacturer that it created the CPU and the CPU key pair according to a known specification. The pledge further states that the CPU can correctly perform authenticated boot procedures, as are described below in more detail. The manufacturer certificate 166 is publicly accessible, yet it cannot be forged without knowledge of the manufacturer's private key K.sub.MFR.sup.-1.
> 
> The CPU 140 has an internal software identity register (SIR) 168, which contains the identity of an authenticated operating system 180 or a predetermined false value (e.g., zero) if the CPU determines that the operating system 180 cannot be authenticated. The operating system (OS) 180 is stored in the memory 142 and executed on the CPU 140. The operating system 180 has a block of code 182 that is used to authenticate the operating system to the CPU during the boot operation. The boot block 182 uniquely determines the operating system, or class of operating systems (e.g. those signed by the same manufacturer). The boot block 182 can also be signed by the OS manufacturer.
> 
> 
> 


-- 
Until later: Geoffrey		esoteric@3times25.net

I didn't have to buy my radio from a specific company to listen
to FM, why doesn't that apply to the Internet (anymore...)?