Patent Publication Number: US-10326741-B2

Title: Secure communication secret sharing

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This Utility patent application is a Continuation of U.S. patent application Ser. No. 15/150,354 filed on May 9, 2016, which is a Continuation of U.S. patent application Ser. No. 14/695,690 filed on Apr. 24, 2015, now U.S. Pat. No. 9,338,147 issued on May 10, 2016, the benefits of which are claimed under 35 U.S.C. § 120, and the contents of which are further incorporated in entirety by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to network monitoring, and more particularly, but not exclusively, to monitoring encrypted network traffic communicated over a network. 
     BACKGROUND 
     On most computer networks, bits of data arranged in bytes are packaged into collections of bytes called packets. These packets are generally communicated between computing devices over networks in a wired and/or wireless manner. A suite of communication protocols is typically employed to communicate between at least two endpoints over one or more networks. The protocols are typically layered on top of one another to form a protocol stack. One model for a network communication protocol stack is the Open Systems Interconnection (OSI) model, which defines seven layers of different protocols that cooperatively enable communication over a network. The OSI model layers are arranged in the following order: Physical (1), Data Link (2), Network (3), Transport (4), Session (5), Presentation (6), and Application (7). 
     Another model for a network communication protocol stack is the Internet Protocol (IP) model, which is also known as the Transmission Control Protocol/Internet Protocol (TCP/IP) model. The TCP/IP model is similar to the OSI model except that it defines four layers instead of seven. The TCP/IP model&#39;s four layers for network communication protocol are arranged in the following order: Link (1), Internet (2), Transport (3), and Application (4). To reduce the number of layers from four to seven, the TCP/IP model collapses the OSI model&#39;s Application, Presentation, and Session layers into its Application layer. Also, the OSI&#39;s Physical layer is either assumed or is collapsed into the TCP/IP model&#39;s Link layer. Although some communication protocols may be listed at different numbered or named layers of the TCP/IP model versus the OSI model, both of these models describe stacks that include basically the same protocols. For example, the TCP protocol is listed on the fourth layer of the OSI model and on the third layer of the TCP/IP model. To assess and troubleshoot communicated packets and protocols over a network, different types of network monitors can be employed. One type of network monitor, a “packet sniffer” may be employed to generally monitor and record packets of data as they are communicated over a network. Some packet sniffers can display data included in each packet and provide statistics regarding a monitored stream of packets. Also, some types of network monitors are referred to as “protocol analyzers” in part because they can provide additional analysis of monitored and recorded packets regarding a type of network, communication protocol, or application. 
     Generally, packet sniffers and protocol analyzers passively monitor network traffic without participating in the communication protocols. In some instances, they receive a copy of each packet on a particular network segment or VLAN from one or more members of the network segment. They may receive these packet copies through a port mirror on a managed Ethernet switch, e.g., a Switched Port Analyzer (SPAN) port, or a Roving Analysis Port (RAP). Port mirroring enables analysis and debugging of network communications. Port mirroring can be performed for inbound or outbound traffic (or both) on single or multiple interfaces. In other instances, packet copies may be provided to the network monitors from a specialized network tap or from a software agent running on the client or server. In virtual environments, port mirroring may be performed on a virtual switch that is incorporated within the hypervisor. 
     In some instances, a proxy is actively arranged between two endpoints, such as a client device and a server device. The proxy intercepts each packet sent by each endpoint and optionally transforms and forwards the payload to the other endpoint. Proxies often enable a variety of additional services such as load balancing, caching, content filtering, and access control. In some instances, the proxy may operate as a network monitor. In other instances, the proxy may forward a copy of the packets to a separate network monitor. 
     Furthermore as information technology infrastructure becomes more complex and more dynamic it may be more difficult to determine and monitor which devices and applications may be operative on a network. Also, the complexity may make it difficult, especially in large networks, for determining dependencies among the network devices and applications that are operative on the networks. However, as more network traffic is being encrypted, it has become more difficult for network monitors to analyze the content of monitored packets in a way that is both useful for analysis and helpful for troubleshooting a particular issue or event in a timely manner. Thus, it is with respect to these considerations and others that the present invention has been made. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the present innovations are described with reference to the following drawings. In the drawings, like reference numerals refer to like parts throughout the various figures unless otherwise specified. For a better understanding of the described innovations, reference will be made to the following Description of Various Embodiments, which is to be read in association with the accompanying drawings, wherein: 
         FIG. 1  illustrates a system environment in which various embodiments may be implemented; 
         FIG. 2  shows a schematic embodiment of a client computer; 
         FIG. 3  illustrates a schematic embodiment of a network computer; 
         FIG. 4  illustrates a logical architecture of a system for secure communication secret sharing in accordance with at least one of the various embodiments; 
         FIG. 5  illustrates a logical architecture of a system for secure communication secret sharing in accordance with at least one of the various embodiments; 
         FIG. 6  illustrates a logical representation of a table that a network monitoring device may employ to associate session keys for secure communication with particular secure communication session and/or network connection flow; 
         FIG. 7  illustrates an overview flowchart of a process that may be arranged to share secrets for secure communication in accordance with at least one of the various embodiments; 
         FIG. 8  illustrates a flowchart of a process that may be arranged to share secrets for secure communication in accordance with at least one of the various embodiments; and 
         FIG. 9  illustrates a flowchart of a process for correlating session keys with secure communication flows in accordance with at least one of the various embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Various embodiments now will be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments by which the invention may be practiced. The embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the embodiments to those skilled in the art. Among other things, the various embodiments may be methods, systems, media or devices. Accordingly, the various embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. The following detailed description is, therefore, not to be taken in a limiting sense. 
     Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment, though it may. Furthermore, the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments may be readily combined, without departing from the scope or spirit of the invention. 
     In addition, as used herein, the term “or” is an inclusive “or” operator, and is equivalent to the term “and/or,” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references. The meaning of “in” includes “in” and “on.” 
     For example embodiments, the following terms are also used herein according to the corresponding meaning, unless the context clearly dictates otherwise. 
     As used herein, the term “session” refers to a semi-permanent interactive packet interchange between two or more communicating endpoints, such as network devices. A session is set up or established at a certain point in time, and torn down at a later point in time. An established communication session may involve more than one message in each direction. A session may have stateful communication where at least one of the communicating network devices saves information about the session history to be able to communicate. A session may also provide stateless communication, where the communication consists of independent requests with responses between the endpoints. An established session is the basic requirement to perform a connection-oriented communication. A session also is the basic step to transmit in connectionless communication modes. 
     As used herein, the terms “network connection,” and “connection” refer to communication sessions with a semi-permanent connection for interactive packet interchange between two or more communicating endpoints, such as network devices. The connection may be established before application data is transferred, and where a stream of data is delivered in the same or different order than it was sent. The alternative to connection-oriented transmission is connectionless communication. For example, the datagram mode of communication used by the Internet Protocol (IP) and the Universal Datagram Protocol (UDP) may deliver packets out of order, since different packets may be routed independently and could be delivered over different paths. Packets associated with a TCP protocol connection may also be routed independently and could be delivered over different paths. However, for TCP connections the network communication system may provide the packets to application endpoints in the correct order. 
     Connection-oriented communication may be a packet-mode virtual circuit connection. For example, a transport layer virtual circuit protocol such as the TCP protocol can deliver packets of data in order although the lower layer switching is connectionless. A connection-oriented transport layer protocol such as TCP can also provide connection-oriented communications over connectionless communication. For example, if TCP is based on a connectionless network layer protocol (such as IP), this TCP/IP protocol can then achieve in-order delivery of a byte stream of data, by means of segment sequence numbering on the sender side, packet buffering and data packet reordering on the receiver side. Alternatively, the virtual circuit connection may be established in a datalink layer or network layer switching mode, where all data packets belonging to the same traffic stream are delivered over the same path, and traffic flows are identified by some connection identifier rather than by complete routing information, which enables fast hardware based switching. 
     As used herein, the term “handshake” refers the data and messages exchanged between a client computer and server computer to establish secure communication channel. The particular secure communication protocol defines the handshake protocol that must be employed to establish a secure communication channel. In at least one of the various embodiments, the purpose of a handshake may be to enable the client and server to agree on one or more cryptographic features to employ, such as, authentication methods, key exchange methods, key sizes, cipher methods, or the like, or combination thereof. 
     As used herein, the terms “session flow” and “network flow” refer to one or more network packets or a stream of network packets that are communicated in a session that is established between at least two endpoints, such as two network devices. In at least one of the various embodiments, flows may be useful if one or more of the endpoints of a session may be behind a network traffic management device, such as a firewall, switch, router, load balancer, or the like. In at least one of the various embodiments, such flows may be used to ensure that the packets sent between the endpoints of a flow may be routed appropriately. 
     Typically, establishing a TCP based connection between endpoints begins with the execution of an initialization protocol and creates a single bi-directional flow between two endpoints, e.g., one direction of flow going from endpoint A to endpoint B, the other direction of the flow going from endpoint B to endpoint A, where each endpoint is at least identified by an IP address and a TCP port. In at least one of the various embodiments, a tuple may be employed to identify a flow. Also, other protocols may establish a separate flow for control information that enables management of at least one or more flows between two or more endpoints. 
     As used herein, the terms “secure communication connection,” “secure communication channel,” or “secure communication session” refer to cryptographically secure network communication sessions between client computers and server computers. For example, SSL/TLS sessions may be considered secure communication sessions. In at least one of the various embodiments, secure communication session will be comprised of network packets that have an encrypted data portion and some portion that is unencrypted. The encrypted portion of the network packets may often be considered the payload or data. The unencrypted portion of the network packets may include meta-data such as routing information, or the like, as determined by the protocol being employed. In some embodiments, participants in a secure communication session may employ cryptographic session keys to encrypt and/or decrypt data included in the network packets comprising a secure communication channel. The particular secure communication protocol being used will define how session keys are exchanged and/or generated. 
     As used herein, the terms “network monitor”, “network monitor device”, or “NMD” refer to an application (software, hardware, or some combination) that is arranged to monitor and record flows of packets in a session that are communicated between at least two endpoints over at least one network. The NMD can provide information for assessing different aspects of these monitored flows. In at least one embodiment, the NMD passively monitors network packet traffic without participating in the communication protocols. This monitoring is performed for a variety of reasons, including troubleshooting and proactive remediation, end-user experience monitoring, SLA monitoring, capacity planning, application lifecycle management, infrastructure change management, infrastructure optimization, business intelligence, security, and regulatory compliance. The NMD can receive network communication for monitoring through a variety of means including network taps, wireless receivers, port mirrors or directed tunnels from network switches, clients or servers including the endpoints themselves, or other infrastructure devices. In at least some of the various embodiments, the NMD may receive a copy of each packet on a particular network segment or virtual local area network (VLAN). Also, for at least some of the various embodiments, they may receive these packet copies through a port mirror on a managed Ethernet switch, e.g., a Switched Port Analyzer (SPAN) port, or a Roving Analysis Port (RAP). Port mirroring enables analysis and debugging of network communications. Port mirroring can be performed for inbound or outbound traffic (or both) on single or multiple interfaces. 
     The NMD may track network connections from and to end points such as a client and/or a server. The NMD may also extract information from the packets including protocol information at various layers of the communication protocol stack. The NMD may reassemble or reconstruct the stream of data exchanged between the endpoints. The NMD may perform decryption of the payload at various layers of the protocol stack. The NMD may passively monitor the network traffic or it may participate in the protocols as a proxy. The NMD may attempt to classify the network traffic according to communication protocols that are used. 
     The NMD may also perform one or more actions for classifying protocols that may be a necessary precondition for application classification. While some protocols run on well-known ports, others do not. Thus, even if there is traffic on a well-known port, it is not necessarily the protocol generally understood to be assigned to that port. As a result, the NMD may perform protocol classification using one or more techniques, such as, signature matching, statistical analysis, traffic analysis, and other heuristics. In some cases, the NMD may use adaptive protocol classification techniques where information used to classify the protocols may be accumulated and/or applied over time to further classify the observed protocols. The NMD may categorize the traffic where categories might include file transfers, streaming audio, streaming video, database access, interactive, gaming, and the like. The NMD may attempt to determine whether the traffic corresponds to known communications protocols, such as HTTP, FTP, SMTP, RTP, TDS, TCP, IP, and the like. 
     As used herein the term “hardware security module” refers to a hardware device or computer arranged for providing additional safeguards for storing and using security/cryptographic information such as, keys, digital certificates, passwords, passphrases, two-factor authentication information, personal identification numbers, or the like. In some embodiments, hardware security modules may be employed to support one or more standard public key infrastructures, and may be employed to generate, manage, and/or store keys pairs, or the like. In some embodiments, hardware security modules may be arranged and/or configured as stand-alone network computers, in other cases, they may be arranged as hardware cards that may be added to a computer. Further, in some cases, hardware security modules may be arranged as a portable computer, and/or incorporated into client computers. 
     As used herein the term “key provider” refers to a computer, hardware security module (HSM), program, service, or process that is arranged to provide, or otherwise communicate a session key to a NMD. In some embodiments, the NMD may request the session key from a key provider. In other embodiments, the key provider may push the session key to the NMD. In at least one of the various embodiments, a key provider may be considered to include a proxy, such as a network firewall, content caches, application delivery controller, as well as one or more intermediary services that may have received a session key from a client, server, or HSM. 
     The following briefly describes embodiments of the invention in order to provide a basic understanding of some aspects of the invention. This brief description is not intended as an extensive overview. It is not intended to identify key or critical elements, or to delineate or otherwise narrow the scope. Its purpose is merely to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
     Briefly stated, various embodiments are directed to monitoring communication over a network using a network monitoring device (NMD) that may be enabled to share secrets that are used for secure communication. In at least one of the various embodiments, the NMD may passively monitor a plurality of network packets that may be communicated between one or more client computers and one or more server computers over the network. In at least one of the various embodiments, if a secure communication session may be determined to be established between a client computer and a server computer, a key provider may provide the NMD a session key that may correspond to the secure communication session. In at least one of the various embodiments, the key provider, may be the client computer, the server computer, or a hardware security module. 
     In at least one of the various embodiments, providing the session key to the NMD may include communicating a request from the NMD to the key provider to provide the session key. Alternatively, in at least one of the various embodiments, providing the session key to the NMD may include receiving a communication from the key provider that includes at least the session key. 
     In at least one of the various embodiments, the NMD may buffer each network packet associated with the secure communication session until the NMD is provided a session key that corresponds to the secure communication session. 
     In at least one of the various embodiments, the NMD may be arranged to determine correlation information from the one or more network packets that are associated with handshake messages used to establish the secure communication session. The correlation information may be used to by the NMD to determine the network connection flow that corresponds to the secure communication session based on a match of the correlation information with correlation information that is provided by the key provider with the session key. Further, in at least one of the various embodiments, the correlation information may include at least one of, an encrypted pre-master secret, Diffie-Hellman public information, a secure socket layer (SSL) session identifier or session ticket, one or more network information tuples, SSL/TLS random values from ClientHello or ServerHello messages, and one or more values derived from the one or more network packets. 
     Further, in at least one of the various embodiments, the NMD may use the session key to decrypt one or more network packets that may be communicated between the client computer and the server computer over the secure communication session. In at least one of the various embodiments, the NMD may then proceed to analyze the secure communication session based on the contents of the one or more decrypted network packets. 
     In at least one of the various embodiments, more than one NMD may be monitoring the network packets on a network. Accordingly, in at least one of the various embodiments, the NMDs may be arranged to communicate the session key and any correlation information to other NMDs enabling them to decrypt the network packets that may be associated with the secure communication session. Further, in at least one of the various embodiments, NMDs may be arranged to communicate with one or more other services, or computers, either local or remote, for obtaining session keys, correlation information, or the like. 
     Illustrated Operating Environment 
       FIG. 1  shows components of one embodiment of an environment in which embodiments of the invention may be practiced. Not all of the components may be required to practice the invention, and variations in the arrangement and type of the components may be made without departing from the spirit or scope of the invention. As shown, system  100  of  FIG. 1  includes local area networks (LANs)/wide area networks (WANs)—(network)  110 , wireless network  108 , client computers  102 - 105 , Application Server Computer  116 , Network Monitoring Device  118 , or the like. 
     At least one embodiment of client computers  102 - 105  is described in more detail below in conjunction with  FIG. 2 . In one embodiment, at least some of client computers  102 - 105  may operate over one or more wired and/or wireless networks, such as networks  108 , and/or  110 . Generally, client computers  102 - 105  may include virtually any computer capable of communicating over a network to send and receive information, perform various online activities, offline actions, or the like. In one embodiment, one or more of client computers  102 - 105  may be configured to operate within a business or other entity to perform a variety of services for the business or other entity. For example, client computers  102 - 105  may be configured to operate as a web server, firewall, client application, media player, mobile telephone, game console, desktop computer, or the like. However, client computers  102 - 105  are not constrained to these services and may also be employed, for example, as for end-user computing in other embodiments. It should be recognized that more or less client computers (as shown in  FIG. 1 ) may be included within a system such as described herein, and embodiments are therefore not constrained by the number or type of client computers employed. 
     Computers that may operate as client computer  102  may include computers that typically connect using a wired or wireless communications medium such as personal computers, multiprocessor systems, microprocessor-based or programmable electronic devices, network PCs, or the like. In some embodiments, client computers  102 - 105  may include virtually any portable computer capable of connecting to another computer and receiving information such as, laptop computer  103 , mobile computer  104 , tablet computers  105 , or the like. However, portable computers are not so limited and may also include other portable computers such as cellular telephones, display pagers, radio frequency (RF) devices, infrared (IR) devices, Personal Digital Assistants (PDAs), handheld computers, wearable computers, integrated devices combining one or more of the preceding computers, or the like. As such, client computers  102 - 105  typically range widely in terms of capabilities and features. Moreover, client computers  102 - 105  may access various computing applications, including a browser, or other web-based application. 
     A web-enabled client computer may include a browser application that is configured to send requests and receive responses over the web. The browser application may be configured to receive and display graphics, text, multimedia, and the like, employing virtually any web-based language. In one embodiment, the browser application is enabled to employ JavaScript, HyperText Markup Language (HTML), eXtensible Markup Language (XML), JavaScript Object Notation (JSON), Cascading Style Sheets (CSS), or the like, or combination thereof, to display and send a message. In one embodiment, a user of the client computer may employ the browser application to perform various activities over a network (online). However, another application may also be used to perform various online activities. 
     Client computers  102 - 105  also may include at least one other client application that is configured to receive and/or send content between another computer. The client application may include a capability to send and/or receive content, or the like. The client application may further provide information that identifies itself, including a type, capability, name, and the like. In one embodiment, client computers  102 - 105  may uniquely identify themselves through any of a variety of mechanisms, including an Internet Protocol (IP) address, a phone number, Mobile Identification Number (MIN), an electronic serial number (ESN), a client certificate, or other device identifier. Such information may be provided in one or more network packets, or the like, sent between other client computers, classification server computer  116 , data sensor computer  118  and enterprise server computer  120 , or other computers. 
     Client computers  102 - 105  may further be configured to include a client application that enables an end-user to log into an end-user account that may be managed by another computer, such as application server computer  116 , network monitoring device  118 , or the like. Such an end-user account, in one non-limiting example, may be configured to enable the end-user to manage one or more online activities, including in one non-limiting example, project management, software development, system administration, configuration management, search activities, social networking activities, browse various websites, communicate with other users, or the like. Further, client computers may be arranged to enable users to provide configuration information, or the like, to network monitoring device  118 . Also, client computers may be arranged to enable users to display reports, interactive user-interfaces, and/or results provided by network monitor device  118 . 
     Wireless network  108  is configured to couple client computers  103 - 105  and its components with network  110 . Wireless network  108  may include any of a variety of wireless sub-networks that may further overlay stand-alone ad-hoc networks, and the like, to provide an infrastructure-oriented connection for client computers  103 - 105 . Such sub-networks may include mesh networks, Wireless LAN (WLAN) networks, cellular networks, and the like. In one embodiment, the system may include more than one wireless network. 
     Wireless network  108  may further include an autonomous system of terminals, gateways, routers, and the like connected by wireless radio links, and the like. These connectors may be configured to move freely and randomly and organize themselves arbitrarily, such that the topology of wireless network  108  may change rapidly. 
     Wireless network  108  may further employ a plurality of access technologies including 2nd (2G), 3rd (3G), 4th (4G) 5th (5G) generation radio access for cellular systems, WLAN, Wireless Router (WR) mesh, and the like. Access technologies such as 2G, 3G, 4G, 5G, and future access networks may enable wide area coverage for mobile computers, such as client computers  103 - 105  with various degrees of mobility. In one non-limiting example, wireless network  108  may enable a radio connection through a radio network access such as Global System for Mobil communication (GSM), General Packet Radio Services (GPRS), Enhanced Data GSM Environment (EDGE), code division multiple access (CDMA), time division multiple access (TDMA), Wideband Code Division Multiple Access (WCDMA), High Speed Downlink Packet Access (HSDPA), Long Term Evolution (LTE), and the like. In essence, wireless network  108  may include virtually any wireless communication mechanism by which information may travel between client computers  103 - 105  and another computer, network, a cloud-based network, a cloud instance, or the like. 
     Network  110  is configured to couple network computers with other computers, including, application server computer  116 , network monitoring device  118 , client computers  102 - 105  through wireless network  108 , or the like. Network  110  is enabled to employ any form of computer readable media for communicating information from one electronic device to another. Also, network  110  can include the Internet in addition to local area networks (LANs), wide area networks (WANs), direct connections, such as through a universal serial bus (USB) port, Ethernet port, other forms of computer-readable media, or any combination thereof. On an interconnected set of LANs, including those based on differing architectures and protocols, a router acts as a link between LANs, enabling messages to be sent from one to another. In addition, communication links within LANs typically include twisted wire pair or coaxial cable, while communication links between networks may utilize analog telephone lines, full or fractional dedicated digital lines including T1, T2, T3, and T4, and/or other carrier mechanisms including, for example, E-carriers, Integrated Services Digital Networks (ISDNs), Digital Subscriber Lines (DSLs), wireless links including satellite links, or other communications links known to those skilled in the art. Moreover, communication links may further employ any of a variety of digital signaling technologies, including without limit, for example, DS-0, DS-1, DS-2, DS-3, DS-4, OC-3, OC-12, OC-48, or the like. Furthermore, remote computers and other related electronic devices could be remotely connected to either LANs or WANs via a modem and temporary telephone link. In one embodiment, network  110  may be configured to transport information of an Internet Protocol (IP). 
     Additionally, communication media typically embodies computer readable instructions, data structures, program modules, or other transport mechanism and includes any information non-transitory delivery media or transitory delivery media. By way of example, communication media includes wired media such as twisted pair, coaxial cable, fiber optics, wave guides, and other wired media and wireless media such as acoustic, RF, infrared, and other wireless media. 
     One embodiment of application server computer  116  is described in more detail below in conjunction with  FIG. 3 . Briefly, however, application server computer  116  includes virtually any network computer capable of hosting applications and/or providing services in network environment. 
     One embodiment of network monitoring device  118  is described in more detail below in conjunction with  FIG. 3 . Briefly, however, network monitoring device  116  includes virtually any network computer capable of passively monitoring communication traffic in a network environment. 
     Although  FIG. 1  illustrates application server computer  116 , and network monitor device  118 , each as a single computer, the innovations and/or embodiments are not so limited. For example, one or more functions of application server computer  116 , and/or network monitoring device  118 , or the like, may be distributed across one or more distinct network computers. Moreover, in at least one embodiment, network monitoring device  118  may be implemented using a plurality of network computers. Further, in at least one of the various embodiments, application server computer  116 , and/or network monitoring device  118  may be implemented using one or more cloud instances in one or more cloud networks. Accordingly, these innovations and embodiments are not to be construed as being limited to a single environment, and other configurations, and other architectures are also envisaged. 
     Illustrative Client Computer 
       FIG. 2  shows one embodiment of client computer  200  that may be included in a system in accordance with at least one of the various embodiments. Client computer  200  may include many more or less components than those shown in  FIG. 2 . However, the components shown are sufficient to disclose an illustrative embodiment for practicing the present invention. Client computer  200  may represent, for example, one embodiment of at least one of client computers  102 - 105  of  FIG. 1 . 
     As shown in the figure, client computer  200  includes a processor device, such as processor  202  in communication with a mass memory  226  via a bus  234 . In some embodiments, processor  202  may include one or more central processing units (CPU) and/or one or more processing cores. Client computer  200  also includes a power supply  228 , one or more network interfaces  236 , an audio interface  238 , a display  240 , a keypad  242 , an illuminator  244 , a video interface  246 , an input/output interface  248 , a haptic interface  250 , a global positioning system (GPS) receiver  232 , and a hardware security module (HSM). 
     Power supply  228  provides power to client computer  200 . A rechargeable or non-rechargeable battery may be used to provide power. The power may also be provided by an external power source, such as an alternating current (AC) adapter or a powered docking cradle that supplements and/or recharges a battery. 
     Client computer  200  may optionally communicate with a base station (not shown), or directly with another computer. Network interface  236  includes circuitry for coupling client computer  200  to one or more networks, and is constructed for use with one or more communication protocols and technologies including, but not limited to, GSM, CDMA, TDMA, GPRS, EDGE, WCDMA, HSDPA, LTE, user datagram protocol (UDP), transmission control protocol/Internet protocol (TCP/IP), short message service (SMS), WAP, ultra wide band (UWB), IEEE 802.16 Worldwide Interoperability for Microwave Access (WiMax), session initiated protocol/real-time transport protocol (SIP/RTP), or any of a variety of other wireless communication protocols. Network interface  236  is sometimes known as a transceiver, transceiving device, or network interface card (NIC). 
     Audio interface  238  is arranged to produce and receive audio signals such as the sound of a human voice. For example, audio interface  238  may be coupled to a speaker and microphone (not shown) to enable telecommunication with others and/or generate an audio acknowledgement for some action. 
     Display  240  may be a liquid crystal display (LCD), gas plasma, light emitting diode (LED), organic LED, or any other type of display used with a computer. Display  240  may also include a touch sensitive screen arranged to receive input from an object such as a stylus or a digit from a human hand. 
     Keypad  242  may comprise any input device arranged to receive input from a user. For example, keypad  242  may include a push button numeric dial, or a keyboard. Keypad  242  may also include command buttons that are associated with selecting and sending images. 
     Illuminator  244  may provide a status indication and/or provide light. Illuminator  244  may remain active for specific periods of time or in response to events. For example, when illuminator  244  is active, it may backlight the buttons on keypad  242  and stay on while the client computer is powered. Also, illuminator  244  may backlight these buttons in various patterns when particular actions are performed, such as dialing another client computer. Illuminator  244  may also cause light sources positioned within a transparent or translucent case of the client computer to illuminate in response to actions. 
     Video interface  246  is arranged to capture video images, such as a still photo, a video segment, an infrared video, or the like. For example, video interface  246  may be coupled to a digital video camera, a web-camera, or the like. Video interface  246  may comprise a lens, an image sensor, and other electronics. Image sensors may include a complementary metal-oxide-semiconductor (CMOS) integrated circuit, charge-coupled device (CCD), or any other integrated circuit for sensing light. 
     Client computer  200  also comprises input/output interface  248  for communicating with external devices, such as a headset, or other input or output devices not shown in  FIG. 2 . Input/output interface  248  can utilize one or more communication technologies, such as USB, infrared, Bluetooth™, or the like. 
     Haptic interface  250  is arranged to provide tactile feedback to a user of the client computer. For example, the haptic interface  250  may be employed to vibrate client computer  200  in a particular way when another user of a computer is calling. In some embodiments, haptic interface  250  may be optional. 
     Further, client computer  200  may also comprise hardware security module (HSM)  252  for providing additional tamper resistant safeguards for generating, storing and/or using security/cryptographic information such as, keys, digital certificates, passwords, passphrases, two-factor authentication information, or the like. In some embodiments, hardware security module may be employed to support one or more standard public key infrastructures (PKI), and may be employed to generate, manage, and/or store keys pairs, or the like. In some embodiments, HSM  252  may be a stand-alone computer, in other cases, HSM  252  may be arranged as a hardware card that may be added to a client computer. 
     Client computer  200  may also include GPS transceiver  232  to determine the physical coordinates of client computer  200  on the surface of the Earth. GPS transceiver  232 , in some embodiments, may be optional. GPS transceiver  232  typically outputs a location as latitude and longitude values. However, GPS transceiver  232  can also employ other geo-positioning mechanisms, including, but not limited to, triangulation, assisted GPS (AGPS), Enhanced Observed Time Difference (E-OTD), Cell Identifier (CI), Service Area Identifier (SAI), Enhanced Timing Advance (ETA), Base Station Subsystem (BSS), or the like, to further determine the physical location of client computer  200  on the surface of the Earth. It is understood that under different conditions, GPS transceiver  232  can determine a physical location within millimeters for client computer  200 ; and in other cases, the determined physical location may be less precise, such as within a meter or significantly greater distances. In one embodiment, however, client computer  200  may through other components, provide other information that may be employed to determine a physical location of the computer, including for example, a Media Access Control (MAC) address, IP address, or the like. 
     Mass memory  226  includes a Random Access Memory (RAM)  204 , a Read-only Memory (ROM)  222 , and other storage means. Mass memory  226  illustrates an example of computer readable storage media (devices) for storage of information such as computer readable instructions, data structures, program modules or other data. Mass memory  226  stores a basic input/output system (BIOS)  224 , or the like, for controlling low-level operation of client computer  200 . The mass memory also stores an operating system  206  for controlling the operation of client computer  200 . It will be appreciated that this component may include a general-purpose operating system such as a version of UNIX, or Linux™, or a specialized client communication operating system such as Microsoft Corporation&#39;s Windows Mobile™, Apple Inc.&#39;s iOS™, Google Corporation&#39;s Android™, or the like. The operating system may include, or interface with a Java virtual machine module that enables control of hardware components and/or operating system operations via Java application programs. 
     Mass memory  226  further includes one or more data storage  208 , which can be utilized by client computer  200  to store, among other things, applications  214  and/or other data. For example, data storage  208  may also be employed to store information that describes various capabilities of client computer  200 . The information may then be provided to another computer based on any of a variety of events, including being sent as part of a header during a communication, sent upon request, or the like. Data storage  208  may also be employed to store social networking information including address books, buddy lists, aliases, user profile information, user credentials, or the like. Further, data storage  208  may also store messages, web page content, or any of a variety of user generated content. 
     At least a portion of the information stored in data storage  208  may also be stored on another component of client computer  200 , including, but not limited to processor readable storage media  230 , a disk drive or other computer readable storage devices (not shown) within client computer  200 . 
     Processor readable storage media  230  may include volatile, non-transitory, nonvolatile, removable, and non-removable media implemented in any method or technology for storage of information, such as computer- or processor-readable instructions, data structures, program modules, or other data. Examples of computer readable storage media include RAM, ROM, Electrically Erasable Programmable Read-only Memory (EEPROM), flash memory or other memory technology, Compact Disc Read-only Memory (CD-ROM), digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other physical medium which can be used to store the desired information and which can be accessed by a computer. Processor readable storage media  230  may also be referred to herein as computer readable storage media and/or computer readable storage device. 
     Applications  214  may include computer executable instructions which, when executed by client computer  200 , transmit, receive, and/or otherwise process network data. Network data may include, but is not limited to, messages (e.g., SMS, Multimedia Message Service (MMS), instant message (IM), email, and/or other messages), audio, video, and enable telecommunication with another user of another computer. Applications  214  may include, for example, a browser  216 , one or more cryptographic providers, such as, crypto provider  218 , secret sharing application  220 , and other applications  221 . 
     Browser  216  may include virtually any application configured to receive and display graphics, text, multimedia, messages, and the like, employing virtually any web based language. In one embodiment, the browser application is enabled to employ HDML, WML, WMLScript, JavaScript, SGML, HTML, HTMLS, XML, and the like, to display and send a message. However, any of a variety of other web-based markup or programming languages may be employed. In one embodiment, browser  216  may enable a user of client computer  200  to communicate with another network computer, such as application server computer  116 , and/or network monitoring device  118 , or the like, as shown in  FIG. 1 . 
     Secret sharing application  220  may be a process or service that is arranged to communicate one or more cryptographic secrets to one or more NMDs, such as, NMD  116 . Further, in at least one of the various embodiments, secret sharing application  220  may be arranged to be a plug-in of browser  216 . Also, in at least one of the various embodiments, secret sharing application  220  may be embedded into cryptographic provider and/or a plug-in associated with cryptographic provider  218 . 
     Other applications  222  may include, but are not limited to, calendars, search programs, email clients, IM applications, SMS applications, voice over Internet Protocol (VOIP) applications, contact managers, task managers, transcoders, database programs, word processing programs, software development tools, security applications, spreadsheet programs, games, search programs, and so forth. 
     Illustrative Network Computer 
       FIG. 3  shows one embodiment of a network computer  300 , in accordance with at least one of the various embodiments. Network computer  300  may include many more or less components than those shown. The components shown, however, are sufficient to disclose an illustrative embodiment for practicing the invention. Network computer  300  may be configured to operate as a server, client, peer, a host, a cloud instance, a network monitoring device, a network hardware security module, or any other computer. Network computer  300  may represent, for example application server computer  116 , network monitoring device  118 , or the like. 
     Network computer  300  includes one or more processor devices, such as, processor  302 . Also, network computer  300  includes processor readable storage media  328 , network interface unit  330 , an input/output interface  332 , hard disk drive  334 , video display adapter  336 , hardware security module  340 , and memory  326 , all in communication with each other via bus  338 . 
     As illustrated in  FIG. 3 , network computer  300  also can communicate with the Internet, or other communication networks, via network interface unit  330 , which is constructed for use with various communication protocols including the TCP/IP protocol. Network interface unit  330  is sometimes known as a transceiver, transceiving device, or network interface card (NIC). 
     Network computer  300  also comprises input/output interface  332  for communicating with external devices, such as a keyboard, or other input or output devices not shown in  FIG. 3 . Input/output interface  332  can utilize one or more communication technologies, such as USB, infrared, NFC, Bluetooth™, or the like. 
     Memory  326  generally includes RAM  304 , ROM  322  and one or more permanent mass storage devices, such as hard disk drive  334 , tape drive, optical drive, and/or floppy disk drive. Memory  326  stores operating system  306  for controlling the operation of network computer  300 . Any general-purpose operating system may be employed. Basic input/output system (BIOS)  324  is also provided for controlling the low-level operation of network computer  300 . 
     Although illustrated separately, memory  326  may include processor readable storage media  328 . Processor readable storage media  328  may be referred to and/or include computer readable media, computer readable storage media, and/or processor readable storage device. Processor readable storage media  328  may include volatile, nonvolatile, non-transitory, non-transitive, removable, and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. Examples of processor readable storage media include RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, solid state storage devices, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other media which can be used to store the desired information and which can be accessed by a computer. 
     Memory  326  further includes one or more data storage  308 , which can be utilized by network computer  300  to store, among other things, applications  314  and/or other data. For example, data storage  308  may also be employed to store information that describes various capabilities of network computer  300 . The information may then be provided to another computer based on any of a variety of events, including being sent as part of a header during a communication, sent upon request, or the like. Data storage  308  may also be employed to store messages, web page content, or the like. At least a portion of the information may also be stored on another component of network computer  300 , including, but not limited to processor readable storage media  328 , hard disk drive  334 , or other computer readable storage medias (not shown) within network computer  300 . 
     Data storage  308  may include a database, text, spreadsheet, folder, file, or the like, that may be configured to maintain and store user account identifiers, user profiles, email addresses, IM addresses, and/or other network addresses; or the like. Data storage  308  may further include program code, data, algorithms, and the like, for use by a processor device, such as processor  302  to execute and perform actions. In one embodiment, at least some of data store  308  might also be stored on another component of network computer  300 , including, but not limited to processor-readable storage media  328 , hard disk drive  334 , or the like. 
     Applications  314  may include computer executable instructions, which may be loaded into mass memory and run on operating system  306 . Examples of application programs may include transcoders, schedulers, calendars, database programs, word processing programs, Hypertext Transfer Protocol (HTTP) programs, customizable user-interface programs, IPSec applications, encryption programs, security programs, SMS message servers, IM message servers, email servers, account managers, and so forth. Applications  314  may also include, web server  316 , crypto provider application  318 , secret sharing application  319 , or the like. 
     Web server  316  may represent any of a variety of information and services that are configured to provide content, including messages, over a network to another computer. Thus, website server  316  can include, for example, a web server, a File Transfer Protocol (FTP) server, a database server, a content server, email server, or the like. Website server  316  may provide the content including messages over the network using any of a variety of formats including, but not limited to WAP, HDML, WML, SGML, HTMLS, XML, Compact HTML (C-HTML), Extensible HTML (XHTML), or the like. 
     Secret sharing application  319  may be a process or service that is arranged to communicate one or more cryptographic secrets to one or more NMDs, such as, NMD  118 . Further, in at least one of the various embodiments, secret sharing application  319  may be arranged to be a plug-in of browser  316 . Also, in at least one of the various embodiments, secret sharing application  318  may be embedded into cryptographic provider and/or a plug-in associated with cryptographic provider  318 . 
     Further, network computer  300  may also comprise hardware security module (HSM)  340  for providing additional tamper resistant safeguards for generating, storing and/or using security/cryptographic information such as, keys, digital certificates, passwords, passphrases, two-factor authentication information, or the like. In some embodiments, hardware security module may be employ to support one or more standard public key infrastructures (PKI), and may be employed to generate, manage, and/or store keys pairs, or the like. In some embodiments, HSM  340  may be a stand-alone network computer, in other cases, HSM  340  may be arranged as a hardware card that may be installed in a network computer. 
     In at least one of the various embodiments, some or all of crypto provider  318  may be arranged to execute on HSM  340 . Also, HSM  340  may provide one or more cryptographic services to crypto provider  318 . 
     Illustrative Logical System Architecture 
       FIG. 4  illustrates a logical architecture of system  400  for secure communication secret sharing in accordance with at least one of the various embodiments. System  400  may be arranged to include a plurality of network devices on first network  402  and a plurality of network devices on second network  404 . Communication between the first network and the second network is managed by switch  406 . Also, NMD  408  is arranged to passively monitor and/or record packets (network packets) that are communicated in network connection flows between a network devices on first network  402  and second network  404 . For example, the communication of flows of packets between the Host B network device and the Host A network device are managed by switch  406  and NMD  408  may be passively monitoring and recording some or all of the network traffic comprising these flows. 
     NMD  408  may be arranged to receive network communication for monitoring through a variety of means including network taps, wireless receivers, port mirrors or directed tunnels from network switches, clients or servers including the endpoints themselves, or other infrastructure devices. In at least some of the various embodiments, the NMD may receive a copy of each packet on a particular network segment or virtual local area network (VLAN). Also, for at least some of the various embodiments, NMDs may receive these packet copies through a port mirror on a managed Ethernet switch, e.g., a Switched Port Analyzer (SPAN) port, or a Roving Analysis Port (RAP). Port mirroring enables analysis and debugging of network communications. Port mirroring can be performed for inbound or outbound traffic (or both) on single or multiple interfaces. 
       FIG. 5  illustrates a logical architecture of system  500  for secure communication secret sharing in accordance with at least one of the various embodiments. In at least one of the various embodiments, system  500  comprises client computer  502 , application server computer  504 , network monitoring device  506 , and optionally, hardware security module  508 . 
     In at least one of the various embodiments, client computer  502  may be a computer that has one or more applications that may be arranged to securely communication with application server computer  504  over network. Secure communication may be comprised of one or more cryptographically secure network communication protocols, including, SSL/TLS, SFTP, SSH, or the like, or combination thereof. For example, in some embodiments, client computer  502  may be hosting a web browser that is securely accessing a website that is served by a web server running on application server computer  504 . Another non-limiting example, may include client computer  502  accessing an application running on application server computer  504  over a virtual private network. As described above, NMD  506  may be arranged to passively monitor the network packets comprising communication between client computer  502  and application server computer  504 . 
     In at least one of the various embodiments, application server computer  504  may employ a network hardware security module, such as, HSM  508  to provide one or more cryptographic services that may be employed to perform secure communication with client computer  502 . For example, HSM  508  may generate and/or store cryptographic keys used (including session keys) for establishing secure communication with client computer  502 . 
     In at least one of the various embodiments, client applications and server applications running on client computers, such as, client computer  502  and/or server computers, such as, server computer  504  may be arranged to employ one or more cryptographic protocols to provide secure communication between them. Various secure communication protocols, such as SSL/TLS may define handshake protocols, authentication protocols, key exchange protocols, or the like, or combination thereof, that implement the secure communication between the clients and servers. Accordingly, in at least one of the various embodiments, the cryptographic protocols may include using one or more session keys to encrypt and/or decrypt the communication traffic. Thus, in at least one of the various embodiments, if a secure communication session is established between a server and a client, an NMD, such as, NMD  506  may require a session key to decrypt the encrypted network packets that may be communicated over the secure communication channel. For example, if a client application running on client computer  502  establishes a secure communication session with a server application running on server computer  504 , NMD  506  may require a session key to decrypt the secure network traffic to perform monitoring and analysis based on the contents of the packets in comprising the secure network traffic. 
     In some cases, NMD  506  may be able to derive and/or generate a session key by passively monitoring the handshake information that may be exchanged between the client and server computer. However, for other cases, the client and server may employ a handshake protocol that cryptographically prevents NMD  506  from being able to obtain or generate a session key using information gathered by passive monitoring. For example, if the client and server employ an ephemeral Diffie-Hellman key exchange or agreement, it may be infeasible for NMD  506  to observe and/or capture the information that may be required to generate the session key using just passive monitoring. Also, in at least one of the various embodiments, other well-known and/or custom forward secrecy or perfect forward secrecy (PFS) variants for key exchange or agreement may also prevent NMD  506  from obtaining or deriving a session key just by using passive monitoring. 
     In some embodiments, where NMD  506  is unable to obtain or derive a session key using passive monitoring, one or more of client computer  502 , server computer  504 , or hardware security module  508 , may be arranged to provide and/or communicate session key information for a given secure communication session to NMD  506 . In such cases, if a secure communication session may be established, a key provider may provide the appropriate session key information to an NMD, such as NMD  506 . 
     In at least one of the various embodiments, NMD  506  may be arranged to request the session key once it has observed and determined that the cryptographic handshake between the client and server is in progress or has finished. In at least one of the various embodiments, key providers may be arranged to communicate (e.g., push) session key information to an NMD after the secure communication session has been established. 
     In at least one of the various embodiments, there may be a time gap between when a client and server established as secure communication session and when the NMD is provided a session key. Accordingly, in at least one of the various embodiments, NMDs may be arranged to buffer the secure communication traffic until a session key for the secure communication channel is provided. If a session key is provided to the NMD, the NMD may first decrypt the buffered encrypted data and then decrypt the secure communication on the fly as it is received by the NMD. 
     In at least one of the various embodiments, if the secure communication traffic may be decrypted by a NMD, such as, NMD  506 , it may perform one or more monitoring and/or analysis actions based on the decrypted contents of the secure communication. 
     As used herein the terms client, or client computer, refer to programs and/or computers that may initiate a request for services from a server computer. Likewise, the terms server, or server computer, refer to programs and/or computers that may respond to a request for services from a client computer. For clarity, clients and servers are described separately, but one of ordinary skill in the art will appreciate that a given computer or program may sometimes operate as a server and other times operate as a client depending on whether it is requesting services or responding to requests for services. 
       FIG. 6  illustrates a logical representation of table  600  that a NMD may employ to associate session keys for secure communication with particular secure communication session and/or network connection flow. In at least one of the various embodiments, table  600  may be implemented using one or more data structures, such as, lists, arrays, associative arrays, or the like, or combination thereof. Furthermore, one of ordinary skill in the art will appreciate that other data structures or table arrangements are within the scope of the innovation described herein. However, the description of table  600  is at least sufficient to enable one or ordinary skill in the art to practice the innovations described herein. 
     In at least one of the various embodiments, some or all of the information represented by table  600  may be stored as flow correlation information  312  in network computer  300 . 
     In at least one of the various embodiments, table  600  may be stored in memory of a NMD. In at least one of the various embodiments, column  602  of table  600  may contain a value that corresponds to a particular network connection, network flow, communication channel, or the like. The NMD may be arranged to index or otherwise identify each network flow that it is monitoring. In at least one of the various embodiments, column  604  may include a cryptographic session key that is associated with a network flow. The session key may correspond to a secure communication session that is occurring on/over the network flow. In at least one of the various embodiments, column  606  may include one or more types of correlation information that may be associated with a network flow. The correlation information values may be used in part to determine which network flow a provided session key corresponds to. As described in more detail below, a key provider may provide correlation information with a session key. Accordingly, the NMD may compare the correlation information provided with the session key to the correlation information captured and/or generated by the NMD. If a match of the correlation information is found, the session key may be associated with the corresponding network flow. And, column  608  may contain one or more fields of additional data that may be associated with a network flow. Column  608  represents additional information and/or metrics that may be captured and/or associated with a given network flow. 
     Generalized Operations 
       FIGS. 7-9  represent the generalized operation for secure communication secret sharing in accordance with at least one of the various embodiments. In at least one of the various embodiments, processes  700 ,  800 , and  900  described in conjunction with  FIGS. 7-9  may be implemented by and/or executed on a single network computer (or network monitoring device), such as network computer  300  of  FIG. 3 . In other embodiments, these processes, or portions thereof, may be implemented by and/or executed on a plurality of network computers, such as network computer  300  of  FIG. 3 . In yet other embodiments, these processes, or portions thereof, may be implemented by and/or executed on one or more virtualized computers, such as, those in a cloud-based environment. However, embodiments are not so limited and various combinations of network computers, client computers, or the like may be utilized. Further, in at least one of the various embodiments, the processes described in conjunction with  FIGS. 7-9  may be used for secure communication sharing in accordance with at least one of the various embodiments and/or architectures such as those described in conjunction with  FIGS. 4-6 . Further, in at least one of the various embodiments, some or all of the action performed by processes  700 ,  800 , and  900  may be executed in part by crypto provider  318 , secret sharing application  319 , and HSM  340 , as well as, crypto provider  218 , secret sharing application  220 , and HSM  252 . 
       FIG. 7  illustrates an overview flowchart of process  700  that may be arranged to share secrets for secure communication in accordance with at least one of the various embodiments. After a start block, at block  702 , in at least one of the various embodiments, a network monitoring device (NMD) monitors communication on a network. As described above, one or more NMDs may be arranged to passively monitor network packets that may be communicated over a network. 
     In at least one of the various embodiments, more than one NMD may be monitoring the same network. Likewise, a network may be divided into one or more sub-network each having one or more NMDs monitoring their network traffic. 
     At block  704 , in at least one of the various embodiments, a client computer and server computer may establish a secure communication session on a network that is being monitored by the NMD. In at least one of the various embodiments, commonly a client application running on the client computer and a server application running on a server computer may be arranged to use one or more secure communication protocols, such as SSL/TLS, to cryptographically secure their communication traffic. 
     In at least one of the various embodiments, the NMD may be prevented from monitoring of the contents/data of the network packets comprising a secure communication. Since, the NMD may not be an endpoint, or an active participant in communication, or otherwise, disposed between the client and server, it may not have access to some or all of the information necessary to decrypt the secure communication traffic. Accordingly, the NMD may not be able to monitor and/or analyze the contents of the secure communication. Note, for some secure communication protocols the NMD may be able to observer/monitor enough information to enable it decrypt the secure communication for monitoring. However, in some cases, such as, secure communication protocols that use one or more variants of ephemeral Diffie-Hellman key exchange or agreement, the NMD may be unable to passively observe sufficient information to enable it to decrypt the secure communication traffic. 
     At block  706 , in at least one of the various embodiments, the NMD may obtain the session key information for the secure communication session. In at least one of the various embodiments, the NMD may be provided session key information from the client, the server, a proxy (e.g., firewall, cache, or application delivery controller, or the like), indirectly by way of a session key broker, a hardware security module (HSM), or the like, that enable it decrypt the secure communication between the client and server. In at least one of the various embodiments, the NMD may be arranged to request the session key information from the client, the server, a proxy, a session key broker, or the HSM. In such cases, the provider of the session key, the key provider, may be arranged to include one or more facilities that may determine a session key and provide it to a NMD upon request. 
     In at least one of the various embodiments, the provider of the session key may be arranged to push the session key information to the NMD. Accordingly, if a secure communication channel between a monitored client and server is established, one of the client, the server, a proxy, a session key broker, or the HSM may provide an appropriate session key to the NMD. 
     In at least one of the various embodiments, the session key information may be provided to the NMD over a separate secure communication channel that may be established between the key provider and the NMD. In at least one of the various embodiments, the session key may be provided over a separate network. In some embodiments, the session key information may be provided using the same network that is being monitored. 
     At block  708 , in at least one of the various embodiments, the NMD may monitor the secure communication session using the session key information. The NMD may passively obtain network traffic associated with the secure communication. Accordingly, the NMD may employ the session key information to decrypt the network packets comprising the secure communication information. If the secure communication may be decrypted, the NMD may monitor and analyze the contents of the communication as necessary. Next, control may be returned to a calling process. 
       FIG. 8  illustrates a flowchart of process  800  that may be arranged to share secrets for secure communication in accordance with at least one of the various embodiments. After a start block, at block  802 , in at least one of the various embodiments, a client and server begin a secure communication handshake. In at least one of the various embodiments, in some cases, clients and servers may be arranged to perform non-secure communication (e.g., unencrypted). Likewise, in other cases, they may be arranged to perform secure communications between each other. Generally, whether the communication is secure or non-secure may be determined by configuration information associated with the applications that are communicating. For example, a web server may be arranged to use secure communication (e.g., SSL/TLS) for certain URLs and non-secure communication for other URLs. 
     Accordingly, the client and server may initiate a handshake process for establishing a secure communication session based on their configuration. In at least one of the various embodiments, the purpose of the handshake may be to enable the client and server to agree on one or more cryptographic features to employ, such as, authentication methods, key exchange methods, key sizes, cipher methods, or the like, or combination thereof. 
     In at least one of the various embodiments, if the client and server can determine/negotiate a set of common features to employ for secure communication, those features may be used to establish a secure communication channel. The contents of handshake messages and their sequence may vary depending on the communication protocols being employed by the client and server. In at least one of the various embodiments, the secure communication protocol that is used may be determined by the applications running on the client computer and the server computer. 
     At block  804 , in at least one of the various embodiments, a network monitoring device (NMD) arranged to the monitor the network being used by the client and server may begin monitoring the network traffic associated with the client and server. In at least one of the various embodiments, secure communication protocols may define handshake protocols that are observable on the network by the NMD. For example, one or more records in the network traffic exchanged during handshaking may be unencrypted, enabling the NMD to determine that handshaking may be occurring between the client and server. In some embodiments, the NMD may determine that handshaking is occurring even though it is unable to obtain cryptographic information, such as, exchanged keys, secrets, or the like, from the handshake messages. 
     At block  806 , in at least one of the various embodiments, at some point, the client and server may complete the handshake procedure and begin communicating encrypted network packets over the secure communication. In at least one of the various embodiments, the NMD monitoring the network may be arranged to observe that the handshake is finished based one or more observable changes in the communication between the client and server. For example, the secure communication protocol TLS records include a Content Type field that may be used to distinguish between handshake records and data traffic records (application records) and other records (e.g., alerts). Other secure communication protocols may employ different yet similar methods that may indicate if a handshake has completed. 
     Further, in at least one of the various embodiments, the NMD may identify additional features of the network traffic that may indicate if a handshake is in process. For example, the NMD may monitor the timing of messages exchanged between the client and server to determine if a handshake is occurring. 
     At block  808 , in at least one of the various embodiments, the NMD may begin buffering the secure communication traffic between the client and server. In at least one of the various embodiments, the NMD may be arranged to continuously buffer network packets associated with monitored sessions using a ring-buffer or similar buffering architecture. The NMD may buffer a portion of the secure communication traffic until such time that it may be enable to decrypt it. The amount of traffic that may be buffered may depend on the amount of available buffer memory and one or more configuration values that may allocate buffer sizes within the NMD. 
     In at least one of the various embodiments, rather than using buffering, the NMD may be arranged to record a value that represents the amount of the encrypted payload traffic that is exchanged before the session key is obtained. This value may enable the NMD to begin decrypting and analyzing when the next block of encrypted traffic is received. 
     At decision block  810 , in at least one of the various embodiments, if the NMD obtains the session key corresponding to the secure communication session between the client and the server, control may flow to block  812 ; otherwise, control may loop back to block  808 . 
     In at least one of the various embodiments, the session key generated during the handshake portion of the communication between the client and the server may be provided to the NMD to enable it to decrypt the secure communication for monitoring. In at least one of the various embodiments, the session key may be provided by a key provider, such as, the client, the server, a proxy, a session key broker, or a hardware security module. 
     In at least one of the various embodiments, an application or service running on the client computer may provide the session key to the NMD over a network. For example, a client such as a web browser running on the client computer may be arranged to provide a session key used for secure communication with a web server (e.g., a website secured using SSL/TLS) to the NMD. In other embodiments, the networking/cryptographic facilities of the client computer may be arranged to provide the session key to the NMD. In some embodiments, the session key may be provided by a library, plug-in, extension, or the like, or combination thereof, used by a client application, a client service, a client process, or the like, running on the client computer. 
     Similarly, in at least one of the various embodiments, an application or service running on the server computer may provide the session key to the NMD over a network. For example, a server such as a web server running on the server computer may be arranged to provide a session key used for secure communication between a web server and a web browser running on a client computer. In other embodiments, the networking/cryptographic facilities of the server computer may be arranged to provide the session key to the NMD. In some embodiments, the session key may be provided by a library, plug-in, extension, or the like, or combination thereof, used by a server application, a server service, a server process, or the like, running on the server computer. 
     In at least one of the various embodiments, a hardware security module and/or a network hardware module may be arranged to provide the session key to the NMD for use in decrypting the secure communication traffic. In at least one of the various embodiments, the HSM may be arranged to communicate the session key to the NMD over a network. 
     In at least one of the various embodiments, the NMD may be arranged to obtain a session key from other sources, such as a network firewall, local or remote content cache, application delivery controller, or the like, or combination thereof. Also, in at least one of the various embodiments, the session key may be provided to the NMD by a session key broker that obtained the session key from the client, server, or HSM. 
     At block  812 , in at least one of the various embodiments, the NMD may employ the session key to monitor secure communication between client and server. In at least one of the various embodiments, the NMD may passively capture encrypted network packets that may comprise the secure communication. The session key provided by the server, client, proxy, session key broker, or HSM, may be used to decrypt the network packets to enable the NMD to perform one or more monitoring and/or analysis functions based on the content of the decrypted network packets. Next, control may be returned to calling process. 
       FIG. 9  illustrates a flowchart of process  900  for correlating session keys with secure communication flows in accordance with at least one of the various embodiments. After a start block, at block  902 , in at least one of the various embodiments, an NMD detects the occurrence of a secure communication handshake. As discussed, above, an NMD may be arranged to determine if a client and server begin a handshake process to establish a secure communication session by monitoring the network traffic of the clients and servers that are on the monitored network. 
     At decision block  904 , in at least one of the various embodiments, if the NMD is arranged and/or configured to collect correlation information, control may flow to block  906 ; otherwise, control may flow to block  908 . 
     At block  906 , in at least one of the various embodiments, the NMD may collect one or more portions of correlation information. In at least one of the various embodiments, particular correlation information captured by the NMD may depend on the secure communication protocol that is being used by the client and server. The captured correlation information may be compared to correlation information that the key provider provides with in addition to the session key. Thus, the correlation information may enable the NMD to associate a provided session key with the particular network flow/secure communication session that the session key may be used for decrypting. 
     In at least one of the various embodiments, a network tuple value that includes that source network address, destination network address, source port value, destination port value, VLAN identifier, or the like, or combination thereof, may be captured/determined for each secure communication channel. Accordingly, if a NMD determines that a network flow is performing a handshake to establish a secure communication channel it may store the network tuple value and associate with the flow that is doing a handshake. (See,  FIG. 6 ). Then, if a key provider provides the session key and correlation information that includes the network tuple information, the NMD may determine the secure communication session that corresponds to the session key. 
     In some embodiments, the cryptographic facility (the key provider) used to communicate the session keys to a NMD may be isolated from the network information of the secure communication session. In these embodiments, a network tuple value corresponding to the secure communication channel may be unknown or otherwise unavailable to the key provider. Accordingly, the correlation information must be something other than a tuple derived from the network connection information. For example, in at least one of the various embodiments, a HSM, such as, network HSM  508  may not have visibility of the network information (e.g., source address, destination address, and so on) associated with the secure communication session. It may just have access to the cryptographic information for a secure communication, absent the network information. For example, it may just have access to the session keys and no awareness of the network information required to generate a network tuple to provide correlation information for the NMD. 
     In at least one of the various embodiments, the NMD may use other features inherent in the secure communication protocol for correlation information. For example, a digest may be generated from one or more of the visible fields in the network packets using a hashing function. Then the digest value may be used to index and identify the secure communication flow at the NMD. (See,  FIG. 6 , column  606 .) In at least one of the various embodiments, fields, values, or data structures from one or more network packets, segments, messages or records derived from the network communication between the client and server may be employed to generate correlation information. In at least one of the various embodiments, the particular information used for generating and/or deriving correlation information may be described/defined using configuration information including one or more rule-based policies, or the like. In some embodiments, the NMD may be configured by an operator to determine/identify the fields, values, or data structures that may be used for correlation information. Likewise, type of configuration information may be provided in a configuration file, configuration database, or the like, or combination thereof. 
     In at least one of the various embodiments, the NMD may be configured to collect/generate correlation information that one or more session key providers may also be able to collect and/or generate. In at least one of the various embodiments, the NMD may be configured to collect and/or generate more than one type of correlation information for each secure communication session. Accordingly, by having multiple sets of correlation information per secure communication flow the NMD may be able to use correlation information compatible with a variety of different session key providers. 
     Accordingly, for a given secure communication session, the NMD may collect/generate network tuple information, TCP sequence numbers, a SSL/TLS Session ID (if any), SSL/TLS Session Ticket (if any), Diffie-Hellman public information (from Diffie-Hellman key exchanges), SSL/TLS random values from ClientHello and/or ServerHello, SSL/TLS ClientKeyExchange and/or ServerKeyExchange (if any), generate a digest of other visible record values, or collect/generate one or more values derived from the network packets of the handshake or the secure communication. Thus, if a key provider sends any one of these types of correlation information with the session key, the NMD may be able to correlate the session key to the its corresponding secure communication session. 
     For example, in at least one of the various embodiments, for the SSL/TLS protocol, ClientHello.random may be a field or value and also a structure (it has a gmt_unix_time field, and an random_bytes field) from the ClientHello handshake message, the ClientHello handshake message is part of SSL/TLS&#39;s Handshake Protocol (or sub-protocol). One or more handshake messages may be contained within one or more SSL/TLS records. These SSL/TLS records may be transmitted over a network using TCP/IP. These records may be contained within one TCP/IP packet or they may span multiple TCP/IP packets. Thus, a NMD may be arranged to employ some or all of the ClientHello.random information as correlation information since particular ClientHello messages/records may correspond to a network flow and/or a secure communication session. 
     At block  908 , in at least one of the various embodiments, the NMD may obtain the correlation information from a key provider or other source on the network. The correlation information may be as described for block  906 . 
     At decision block  910 , in at least one of the various embodiments, if a secure session is established, control may flow to block  912 ; otherwise, control may loop back to decision block  904  to continue the handshake process between the client and server. As discussed above, the NMD may monitor the network packets comprising handshake traffic to determine if the session has finished the handshake process and moved onto a secure communication session. At block  912 , in at least one of the various embodiments, since secure communication has been established between the client and the server, the NMD may begin buffering the secure communication, as discussed above. 
     At decision block  912 , in at least one of the various embodiments, if the NMD obtains a session key and other correlation information for the secure communication, control may flow to block  914 ; otherwise, control may loop to back block  912 . In at least one of the various embodiments, the key provider that is arranged to provide the session key to the NMD may provide the session key and the other correlation information to the NMD. 
     At block  914 , in at least one of the various embodiments, the NMD may correlate the session key to a secure communication session that it is monitoring. In at least one of the various embodiments, the NMD may employ the correlation information to determine which of the monitored network connection flows corresponds to the provided session key. In at least one of the various embodiments, the NMD may have collected multiple types of correlation information, if so it may test and/or compare each type of correlation information to determine if there is a match. If a match is found the NMD may associated the session key with the determined corresponding secure communication session. 
     At block  916 , in at least one of the various embodiments, the NMD may employ the provided session key to decrypt (as necessary) the secure communication session. In at least one of the various embodiments, the NMD may employ its own cryptographic facilities to independently decrypt the network packets that are associated with the secure communication session. Accordingly, in at least one of the various embodiments, the NMD is not responsible for encrypting or decrypting the communication traffic for the client and server that are participating in the secure communication session. Rather, the client and server encrypt and decrypt the communication traffic using their own copies of the session key and their own cryptographic facilities. Next, control may be returned to a calling process. 
     It will be understood that each block of the flowchart illustration, and combinations of blocks in the flowchart illustration, can be implemented by computer program instructions. These program instructions may be provided to a processor to produce a machine, such that the instructions, which execute on the processor, create means for implementing the actions specified in the flowchart block or blocks. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer-implemented process such that the instructions, which execute on the processor to provide steps for implementing the actions specified in the flowchart block or blocks. The computer program instructions may also cause at least some of the operational steps shown in the blocks of the flowchart to be performed in parallel. Moreover, some of the steps may also be performed across more than one processor, such as might arise in a multi-processor computer system. In addition, one or more blocks or combinations of blocks in the flowchart illustration may also be performed concurrently with other blocks or combinations of blocks, or even in a different sequence than illustrated without departing from the scope or spirit of the invention. 
     Accordingly, blocks of the flowchart illustration support combinations of means for performing the specified actions, combinations of steps for performing the specified actions and program instruction means for performing the specified actions. It will also be understood that each block of the flowchart illustration, and combinations of blocks in the flowchart illustration, can be implemented by special purpose hardware based systems, which perform the specified actions or steps, or combinations of special purpose hardware and computer instructions. The foregoing example should not be construed as limiting and/or exhaustive, but rather, an illustrative use case to show an implementation of at least one of the various embodiments of the invention. 
     The above specification, examples, and data provide a complete description of the composition, manufacture, and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.