Patent Abstract:
Embodiments of apparatuses, articles, methods, and systems for binding various platform identities for a policy negotiation are generally described herein. Other embodiments may be described and claimed.

Full Description:
RELATED APPLICATION 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 11/323,333, filed Dec. 29, 2005, entitled “METHOD, APPARATUS AND SYSTEM FOR PLATFORM IDENTITY BINDING IN A NETWORK NODE,” and claims priority to the Ser. No. 11/323,333 application. 
     
    
     FIELD 
       [0002]    Embodiments of the present invention relate generally to the field of networks, and more particularly to binding a plurality of platform identities on a node to be used in such networks. 
       BACKGROUND 
       [0003]    Wireless networks are proliferating at a rapid pace as computer users become increasingly mobile. Wireless networks offer users significant flexibility to “roam” across networks without being tied to a specific location. This roaming must be managed by a variety of management solutions. One downside of wireless networks, however, is that they typically face significant security issues. Since the connection is “wireless,” i.e., not physical, and connects to different administrative domains, any party with a compatible wireless network interface may position themselves to inspect and/or intercept wireless packets. In other words, any third-party hacker or attacker may, with relative ease, gain access to packets being transmitted across a wireless network, regardless of who the packets are actually destined for. Employment of security measures to control access to a network may help secure the network; however, administration may be complicated by an increasing amount of entities requesting access. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which: 
           [0005]      FIG. 1  illustrates a network in accordance with an embodiment of the present invention; 
           [0006]      FIG. 2  illustrates an end node utilizing active management technology in accordance with an embodiment of the present invention; 
           [0007]      FIG. 3  illustrates an end node utilizing a virtualized active management technology in accordance with an embodiment of the present invention; 
           [0008]      FIG. 4  illustrates an end node utilizing active management technology in accordance with another embodiment of the present invention; 
           [0009]      FIG. 5  illustrates a policy negotiation of an end node in accordance with an embodiment of the present invention; 
           [0010]      FIG. 6  illustrates a policy negotiation between network entities in accordance with an embodiment of the present invention; and 
           [0011]      FIG. 7  illustrates a session-state data structure in accordance with an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Embodiments of the present invention may provide a method, apparatus, and system for enabling a secure wireless platform. More specifically, embodiments of the present invention may provide a network node capable of binding a plurality of platform identities in negotiation of an access policy to the network. 
         [0013]    Various aspects of the illustrative embodiments will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that alternate embodiments may be practiced with only some of the described aspects. For purposes of explanation, specific devices and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that alternate embodiments may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments. 
         [0014]    Further, various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present invention; however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation. 
         [0015]    The phrase “in one embodiment” is used repeatedly. The phrase generally does not refer to the same embodiment; however, it may. The terms “comprising,” “having,” and “including” are synonymous, unless the context dictates otherwise. 
         [0016]    The phrase “A and/or B” means “(A), (B), or (A and B).” The phrase “at least one of A, B and C” means “(A), (B), (C), (A and B), (A and C), (B and C) or (A, B and C).” 
         [0017]      FIG. 1  illustrates a network  100  having network nodes  104 ,  108 , and  112  communicatively coupled to one another via communication links such as over-the-air links  116  and  120  as shown in accordance with an embodiment of the present invention. The over-the-air links  116  and  120  may be a range of frequencies within the radio spectrum, or a subset therein, designated for wireless communication between the nodes of the network  100 . In other embodiments, communication links may additionally/alternatively include wired links. 
         [0018]    In discussion of the present embodiment the node  104  may also be referred to as end node  104 , the node  108  may also be referred to as a network access device (NAD)  108 , and the node  112  may also be referred to as authentication node  112 . However, in various embodiments, the nodes  104 ,  108 , and  112  may be any type of device that is capable of communicating with other devices over the network  100 . Generally such devices may include personal computers, servers, access points, laptops, portable handheld computers (e.g., personal digital assistants or “PDAs”), set-top boxes, intelligent appliances, wireless telephones, web tablets, wireless headsets, pagers, instant messaging devices, digital cameras, digital audio receivers, televisions and/or other devices that may receive and/or transmit information wirelessly (including hybrids and/or combinations of the aforementioned devices). 
         [0019]    The NAD  108  may serve as an entry point to provide the end node  104  with access to other nodes of the network  100 , including node  112  as well as other devices not specifically shown. The NAD  108  may be a stand-alone device and/or be incorporated as part of another network device such as a network bridge, router, or switch. 
         [0020]    At a network entry event, e.g., a power-on event or an event signifying end node  104  has come within the transmission/reception range of NAD  108 , the end node  104  may engage in a negotiation with the authentication node  112 , through the NAD  108 , that is designed to procure an access policy to control the end node  104  access and/or participation with the network  100 . This may sometimes be referred to as end-point access control and verification (EACV). This EACV may be used to facilitate, e.g., authenticated client access to an enterprise network. The authentication node  112  may include an authentication device  124  to provide preliminary authentication measures to verify aspects of communication from end node  104 , and a policy decision point (PDP) device  128  to formulate and communicate a network access policy to the NAD  108  and/or the end node  104 , to control network access of the end node  104 . The authentication device  124  and the PDP  128  may be co-located in the same device or separate from one another. 
         [0021]    The end node  104  may include a host partition  132 , including an operating system (OS) and other components to provide various user functions. The end node  104  may also have a dedicated partition  136 , which may operate independently from the operating system of the host partition  132 , to provide various management functions. In an embodiment, the dedicated partition  136  may provide a network administrator access to the end node  104  regardless of the power state or OS condition. This ability to communicate with the end node  104  remotely may be called “out-of-band” (OOB) management to indicate that the channel may be OS-agnostic and always available. 
         [0022]    The host partition  132  may include an upper layer  140 , which may include the OS, coupled to a network interface, e.g., a wireless network interface card (WNIC)  144 , to access the over-the-air link  116 . More specifically, the upper layer  140  may be coupled to a media access control (MAC) layer  148  of the WNIC  144 , which is in turn coupled to a physical (PHY) layer  152 . Similarly, an upper layer  156  of the dedicated partition  136  may access the over-the-air link  116  through the MAC layer  160 , of the WNIC  144 , and the PHY layer  152 . The PHY layer  152 , which may refer to the physical layer in the Open Systems Interconnect (OSI) model, may provide the hardware for the end node  104  to send and receive data. 
         [0023]    The MAC layers  148  and  160 , which may be sublayers of the data link layer of the OSI model, may be responsible for transmitting data packets between the WNIC  144  and the upper layers  140  and  156 , respectively. Each of the MAC layers  148  and  160  may provide framing, addressing, and/or medium accessing operations to facilitate data being transmitted to/from the respective upper layers  140  and  156 . 
         [0024]    In various embodiments, upper layers  140  and/or  156  may include one or more layers and/or sublayers of the OSI model including, a logical link control sublayer, a network layer, a transport layer, a session layer, a presentation layer, and/or an application layer. 
         [0025]    While a node having multiple MAC layers may have certain advantages, it may also complicate management and procurement of network access permissions as the upper layers  140  and  156  may be working independently and potentially unaware of one another. The operation of the MAC layers  148  and  160  and/or the upper layers  140  and  156 , may contribute to the existence of multiple identities on the platform. Other network entities, e.g., authentication node  112 , may not realize the various identities are operating from a common platform. As used herein, “platform” may refer to the general framework of the end node  104  including, e.g., the various hardware, software, and/or firmware configurations, some of which are to be described in further detail below. 
         [0026]    Therefore, in accordance with an embodiment of the present invention, the dedicated partition  136  may provide an independent and secure environment to bind the various identities of the end node  104  to one another. With the platform identities bound to one another, the dedicated partition  136  may perform various platform policy negotiations with the authentication node  112  in order to procure a platform policy for network access. As used herein, a platform policy may include one or more network access policies and/or filters, which may be applied to the entities of a platform, or a subset thereof. The platform policy may be applied through hardware and/or software components on the platform. Further details of these interactions are described in detail later in the specification. 
         [0027]    While some embodiments of the present invention are discussed with two MAC layers, other embodiments may have less or more MAC layers. 
         [0028]    Although  FIG. 1  illustrates two partitions, host partition  132  and dedicated partition  136 , other embodiments may have any number of partitions including, e.g., a dedicated partition and a plurality of host partitions. 
         [0029]    In various embodiments, the dedicated partition  136  may comprise a variety of different types of partitions, including an entirely separate hardware partition (e.g., utilizing Active Management Technologies (AMT), “Manageability Engine” (ME), Platform Resource Layer (PRL) and/or other comparable or similar technologies) and/or a virtualized partition (e.g., a virtual machine in a Virtualization Technology (VT) scheme). In various embodiments, a virtualized host may also be used to implement AMT, ME, and PRL technologies (as described in further detail below). 
         [0030]    In this embodiment, the nodes  104 ,  108 , and  112  may each have antennae structures  162 ,  164 , and  168 , respectively, to facilitate wireless transmission/reception of data. An antenna structure may provide a respective wireless network interface with communicative access to an over-the-air link. In various embodiments, each of the antenna structures  162 ,  164 , and/or  168  may include one or more directional antennas, which radiate or receive primarily in one direction (e.g., for 120 degrees), cooperatively coupled to one another to provide substantially omnidirectional coverage; or one or more omnidirectional antennas, which radiate or receive equally well in all directions. 
         [0031]    In various embodiments, the nodes  104 ,  108 , and/or  112  may have one or more transmit and/or receive chains (e.g., a transmitter and/or a receiver and an antenna). For example, in various embodiments, nodes  104 ,  108 , and/or  112  may be a single-input, single-output (SISO) node, a multiple-input, multiple-output (MIMO) node, single-input, multiple-output (SIMO), or multiple-input, single-output (MISO) node. 
         [0032]    The network  100  may comply with a number of topologies, standards, and/or protocols. In one embodiment, various interactions of the network  100  may be governed by a standard such as one or more of the American National Standards Institute/Institute of Electrical and Electronics Engineers (ANSI/IEEE) standards (e.g., IEEE 802.1X-REV-2004, along with any updates, revisions, and/or amendments to such). In various embodiments, the network  100  may additionally or alternatively comply with other communication standards, e.g., other 802.1 standards, 802.11 standards, 802.16 standards, standards conforming to the 3G International Telecommunications Union (ITU) specification for mobile communications technology, etc. 
         [0033]    In various embodiments, the network  100  may comprise any type of network architecture including, but not limited to, local area network (LANs), wireless LANs (WLANs), wireless wide area networks (WWANs), wireless metropolitan area network (WMAN) and/or corporate intranets. 
         [0034]      FIG. 2  illustrates an end node  200  utilizing AMT in accordance with an embodiment of the present invention. The end node  200  may be similar to, and substantially interchangeable with, end node  104 . Various embodiments of the present invention may also be implemented in other similar and/or comparable implementations of AMT. Only the components pertinent to describing the AMT environment have been illustrated in order not to unnecessarily obscure embodiments of the present invention, additional components may be included without departing from the spirit of embodiments of the invention. 
         [0035]    Thus, as illustrated in  FIG. 2 , the end node  200  may include a host OS  204 , running on a host partition, and system hardware  208 . According to one embodiment, the hardware  208  may include two processors, a host processor  212  to perform processing tasks for host OS  204  and a dedicated processor  216  dedicated exclusively to managing the device via AMT  218  running on a dedicate partition. Each processor may have associated resources on the end node  200  and may share one or more other resources. Thus, as illustrated in this example, host processor  212  and dedicated processor  216  may each have portions of memory dedicated to them, e.g., host memory  220  and dedicated memory  224 , respectively; portions of a NIC  228  dedicated to them, e.g., host MAC layer  232  and dedicated MAC layer  236 , respectively; but they may share other portions of the NIC  228 , e.g., PHY layer  240 . 
         [0036]      FIG. 3  illustrates an end node  300  utilizing virtualization in accordance with an embodiment of the present invention. The end node  300  may be similar to, and substantially interchangeable with, end node  104 . It may include only a single processor  304  but a virtual machine monitor (VMM)  308  on the device may present multiple abstractions and/or views of the device, such that the underlying hardware of the node  300  appears as one or more independently operating virtual machines (VMs), e.g., host partition  312  and dedicated partition  316 . VMM  308  may be implemented in software (e.g., as a stand-alone program and/or a component of a host operating system), hardware, firmware and/or any combination thereof. VMM  308  may manage allocation of resources on the node  300  and perform context switching as necessary to cycle between the host partition  312  and the dedicated partition  316  according to a round-robin or other predetermined scheme. Although only processor  304  is illustrated, embodiments of the present invention are not limited to only one processor. In various embodiments, multiple processors may also be utilized within a virtualized environment. For example, if the end node  300  includes two processors the dedicated partition  316  may be assigned a dedicated processor while the host partition  312  (and other host partition VMs) may share the resources of a host processor. 
         [0037]    While the node  300  shows two VM partitions, host partition  312  and dedicated partition  316 , other embodiments may employ any number of virtual machines. VMs may function as self-contained partitions respectively, running their own software hosted by VMM  308 , illustrated as host software  320  and AMTsoftware  324 . 
         [0038]    The host software  320  and AMT software  324  may each operate as if it were running on a dedicated computer rather than a virtual machine. That is, host software  320  and AMT software  324  may each expect to control various events and have access to hardware resources on node  300 , e.g., a NIC  328 . 
         [0039]    A physical hardware partition with a dedicated processor (as illustrated in  FIG. 2 , for example) may provide a higher level of security than a virtualized partition (as illustrated in  FIG. 3 , for example), but embodiments of the invention may be practiced in either environment and/or a combination of these environments to provide varying levels of security. For the purposes of simplicity, embodiments of the invention are described in an AMT environment, but embodiments of the invention are not so limited. Instead, any reference to AMT, a “dedicated partition,” a “secure partition,” a “security partition,” and/or a “management partition” shall include any physical and/or virtual partition (as described above). 
         [0040]      FIG. 4  illustrates a node  400  in accordance with an embodiment of the present invention. The node  400  may be similar to, and substantially interchangeable with, the end node  104 . The node  400  may include a host partition  404 , a dedicated partition, e.g., AMT  408 , and a NIC  412 , which may be similar to like-named elements described above. The AMT  408  may be separated from the host partition  404 , e.g., via physical separation, virtual separation, or a combination thereof, to enhance the security on the wireless platform. 
         [0041]    The host partition  404  may include components such as an ME agent  416  to provide an ME of the AMT  408  with limited access and control of components of the host partition  404 . Access to the ME agent  416  by the operating system of the host partition  404  may be restricted, wholly or in part. The ME agent  416 , which may be limited to a network stack  420 , may gather data on critical parameters about behavior and/or state of the host partition  404 , may provide certain controls of the host partition  404 , e.g., reboot, and/or may provide various security mechanisms. Interactions between the host partition  404  and the AMT  408  may take place over a dedicated channel  424  protected against forgery, eavesdropping, delayed messages, and/or replay attacks. 
         [0042]    In some embodiments, the network stack  420 , e.g., Transport Control Protocol (TCP), Internet Protocol (IP), User Dependent Protocol (UDP), and/or Dynamic Host Configuration Protocol (DHCP), may perform various routing, flow control, segmentation/desegmentation, and/or error control functions. 
         [0043]    In some embodiments the host partition  404  may have an authenticator  428  complying with, e.g., an extensible authentication protocol (EAP) framework. The authenticator  428  may allow for authentication and/or key generation procedures with other entities, e.g., the NAD  108  and/or authentication node  112 . 
         [0044]    In some embodiments, the host partition  404  may also have a driver  432  that may be part of a link layer implementation within an OS, to facilitate communication between the components of the host partition  404  and the NIC  412 . 
         [0045]    As illustrated, the AMT  408  may include an authenticator  436 , a network stack  440 , and a driver  444 , which may be similar to like-named components of the host partition  404 . The AMT  408  may also include an end-point access control (EAC) trust agent  448  and a posture attestor  452  to facilitate collection and attesting of platform posture information. In some embodiments, the AMT  408  may also have a policy applicator  456  to facilitate application of a platform policy. 
         [0046]    In an embodiment, the end node  400  may include a trusted platform module  460  coupled to the host partition  404  and the dedicated partition  408  for establishing a root of trust between the partitions. 
         [0047]    Details of the interaction of the various components described above may be given below in accordance with some embodiments. 
         [0048]      FIG. 5  illustrates a policy negotiation of the end node  400  in accordance with an embodiment of the present invention. A platform policy negotiation may be initiated at the beginning of a communication session ( 500 ). Reference to operations depicted in  FIG. 5  may be indicated by numerals enclosed in parentheses. The AMT  408  may access the over-the-air link  116  and perform registration and mutual authentication operations with the authentication node  112  via the NAD  108  ( 504 ). The trust agent  448  may collect posture information on the AMT  408  and transmit the collected posture information to the authentication node  112 , via the NAD  108 . Posture information may be information related to the state of the AMT  408  which may include, but is not limited to, basic input/output system (BIOS) revision level, firmware revision level, antivirus state, status, and/or configuration settings. 
         [0049]    The AMT  408  may be deemed to be a compliant entity upon successful registration and mutual authentication and may therefore be validated by the authentication node  112 . Upon validation, the AMT  408  may cooperate with the authentication node  112  to effectively bind the host partition  404  to the AMT  408  ( 508 ). In one embodiment, the binding of the identities may communicate to other network participants, e.g., NAD  108 , authentication node  112 , network administrator, etc., that the host partition  404  and the AMT  408  co-reside on the end node  400 . This may, in turn, facilitate assignment and enforcement of the platform policy received from the authentication node  112 . 
         [0050]    The trust agent  448  may cooperate with the ME agent  416  over the dedicated channel  424  to collect posture information on the host partition  404 . The host posture information may be attested through the posture attestor  452 . In some embodiments, posture information may be attested through cryptographic signing mechanisms. This posture information may then be registered with the authentication node  112  ( 512 ). 
         [0051]    The AMT  408  may then receive a platform policy from the authentication node  112 , more particularly, from the PDP  128 . The policy applicator  456  may then verify the policy and implement it on the host partition  404  ( 516 ). 
         [0052]      FIG. 6  illustrates a more detailed policy negotiation in accordance with an embodiment of the present invention. In this embodiment, at initiation the host partition  404  and the AMT  408  may establish a root of trust by having the trusted platform module  460  sign certificate (Cert-AMT)  600  and certificate (Cert-H)  604  for the AMT  408  and the host partition  404 , respectively. These certificates may be used to ensure that both the host partition  404  and the AMT  408  co-reside on the same platform. These certificates may be signed by one or more of the following parties: original equipment manufacturer (OEM), enterprise information technology (IT) department, platform vendor, or other trusted party. 
         [0053]    In an embodiment, the AMT  408  may initially transmit a message  608  to block the driver  432  of the host partition  404  from initiating connections with the NAD  108  pending registration and authentication operations of the AMT  408 . 
         [0054]    In accordance with an embodiment of the present invention, the AMT  408  and authentication node  112  may perform a mutual authentication and registration exchange  610 . The AMT  408 , using Cert-AMT, may perform a mutual authentication exchange  612  with the authentication node  112 , using Cert-AN. This mutual authentication exchange  612  may result in a shared secret between the AMT  408  and the authentication node  112  that may be referred to as a master secret key (MSK). The MSK may be used to derive a tunnel session key (TSK) and/or a key confirmation key (KCK). In various embodiments, the TSK and/or KCK may be used to facilitate protection of the communication channel between the AMT  408  and the authentication node  112  for payload integrity verification, confidentiality, and prevention of replay attacks. 
         [0055]    In an embodiment, the authentication node  112  may send message  616  to query the AMT  408  for posture information. The AMT  408  may transmit its posture information in a message  620   KCK  that may be protected with a message authentication code computed under the KCK. The authentication node  112  may use its KCK to verify the integrity of the AMT  408  posture communication and, if verified, transmit acceptance message  624 . Protection of a message with a message authentication code computed under KCK may be represented by the KCK subscript. Subsequent verification of a KCK protected message at the receiving entity through use of the receiving entity&#39;s KCK may be assumed unless otherwise stated. This symmetric key authentication may be used to reduce the computational burden on the AMT  408 , which may have a constrained processor. However, other embodiments may use other types of authentication. 
         [0056]    In an embodiment, the authentication node  112  may use its MSK to derive a pairwise master key (PMK), which it may subsequently provide to the NAD  108  in message  628  to be used to control the AMT  408  access to the network  100 . The AMT  408 , which may use its MSK to derive the PMK, may communicate the PMK to the NAD  108  to gain access to the network  100 . If the NAD  108  determines that the PMK provided by the authentication node  112  matches the PMK provided by the AMT  408  it may allow the AMT  408  access. 
         [0057]    The AMT  408  may complete its link authentication procedures and derive appropriate link layer keys with the link network peer  632 . As a result of the above operations, a posture authenticated AMT  408  may have access to the network  100  as a trusted entity  636 . 
         [0058]    The authenticated AMT  408  and the authentication node  112  may participate in the identity binding exchange  638  to bind the host partition  404  with the AMT  408 . After the AMT has collected a list of the host identities on the platform for which it will be reporting posture on, e.g., a host-id list, the AMT  408  may communicate the host-id list in a message  640   KCK  to the authentication node  112 . In an embodiment, the host-id list may include MAC addresses of the hosts. 
         [0059]    In an embodiment, message  640   KCK  may also include a Hash-SS. The Hash-SS may be used as session identifier in the negotiation to provide information relating to a present state of a session-state data structure of the AMT  408 . The authentication node  112  may use this information to fill in corresponding fields of its session-state data structure.  FIG. 7  illustrates a session-state data structure  700  that may be used in embodiments of the present invention. 
         [0060]    In an embodiment, the message  640   KCK  may also include a liveness marker, e.g., a random value (Nonce-AMT). The Nonce-AMT may be an unpredictable, random value generated by the AMT  408  using a hardware and/or software random number generator. The use of nonces to facilitate liveness check will be described in further detail below. 
         [0061]    In an embodiment, the message  640   KCK  may also include a MAC address of the AMT (MAC-AMT). The MAC-AMT may include an Internet Protocol (IP) address assigned by a network dynamic host configuration process (DHCP) server. 
         [0062]    In response to message  640   KCK , the authentication node may communicate a message  644   KCK  including, e.g., a MAC address of the authentication node  112  (MAC-AN), a Hash-SS, Nonce-ME, and/or a liveness marker generated by the authentication node  112  (Nonce-AN). The AMT  408  may verify KCK integrity of  644   KCK  and liveness and transmit message  648   KCK  communicating Hash-SS and Nonce-AN. 
         [0063]    The generation, transmission, and repetition of the Nonce values of this identity binding  508  may provide a bi-party proof-of-liveness check. For example, repetition of Nonce-AMT in the message  644   KCK  may show that the message  644   KCK  was generated after receiving message  640   KCK . 
         [0064]    Following the binding of the identities, the AMT  408  may send message  652  to the driver  432  to initiate connection with NAD  108  so that the host partition  404  may acquire an IP address from the network DHCP server. 
         [0065]    In an embodiment, following the identity binding exchange  638 , the entities may engage in a posture registration exchange  656 . The authentication node  112  may transmit a liveness marker, e.g., a second generated nonce value (Nonce-AN2) in a message  660 . The AMT  408  may send a message  664  to the host partition  404  requesting posture information (Host-Posture). The AMT  408  may then transmit message  668   KCK  to authentication node  112  including, e.g., Hash-SS, Host-posture, Nonce-AN2, and another nonce value (Nonce-AMT2). The authentication node  112  may verify the integrity and liveness of the message  668   KCK  and transition into a policy exchange  672  by transmitting message  676   KCK , which may include hash-SS, an access policy for the host partition  404  (Host-Policy), and/or Nonce-AMT2. 
         [0066]    The AMT  408  may verify the integrity and liveness of the message  676   KCK  and proceed to transmit a message  680  to implement the Host-policy on the end node  400  through the policy applicator  440 . The AMT  408  may transmit a confirmation message  684   KCK  to indicate that the policies were applied correctly. The confirmation message  684   KCK  may include a Hash-SS, an indication of the status of the policy on the platform (e.g., Policy-Install-OK), a hash of which policies were applied (e.g., Hash-Host-Policy), and/or another liveness marker (Nonce-AMT3). As a result of the above-described exchanges, the platform end point access control verification may complete  688 . 
         [0067]    While  FIG. 6  illustrates a policy negotiation include the sequential transmission and reception of messages having defined content, other embodiments may have policy negotiations including additional/alternative sequences and/or content. 
         [0068]    Although the network nodes are shown and described above as having several separate functional elements, one or more of the functional elements may be combined with other elements and may be implemented by combinations of various hardware and logic circuitry for performing at least the functions described herein. For example, processing element, such as the dedicated processor  216  of the end node  200 , may comprise an implementing processor packaged in the network interface card  228 . 
         [0069]    Although the present invention has been described in terms of the above-illustrated embodiments, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This description is intended to be regarded as illustrative instead of restrictive on embodiments of the present invention.

Technology Classification (CPC): 7