Abstract:
A cooperative processing and escalation method and system for use in multi-node application-layer security management is disclosed. The method includes the steps of identifying individual application security nodes, grouping and configuring nodes for cooperative processing, assigning the default operational mode at each node, assignment of logging and alert event tasks at each node, and defining escalation and de-escalation rules and triggers at each node. Both loosely-coupled and tightly-coupled configurations, each with its cooperative processing model, are disclosed. The method includes provision for central console configuration and control, near real-time central console dashboard operations interface, alert notification, and operator override of operational modes and event tasks.

Description:
FIELD OF INVENTION  
       [0001]     The present invention relates generally to the field of application-layer security systems, and more particularly, to a system and method for achieving cooperative processing and control of application-layer security by using loosely and tightly coupled nodes of application firewalls, application monitors and data security enforcement points together with operational and escalation rules.  
       DESCRIPTION OF RELATED ART  
       [0002]     As business and government applications are made available to intended users via intranets, extranets and the Internet, exposure to hackers has become a critical problem in the Information Technology (“IT”) Operations field. Systems that provide security at lower layers of the networked environment in the open systems interconnection (“OSI”) model provide little or no defense from hackers gaining unauthorized access to assets, information and sensitive data using application-layer protocols.  FIG. 1  illustrates an OSI model  100  that defines a networking framework for implementing protocols in seven layers. The application-layer  110  of the OSI model includes the entire logical application, including n-tier applications installed on multiple servers, dedicated to specific functions for application processing and data access. Typical attacks by economically or politically motivated “hackers” target unique application protocol and interface vulnerabilities, repeatedly probing the targeted site using various techniques until entry is gained. Other “malicious users,” even those with legitimate access rights such as employees, might steal sensitive data in large batches or in small, repetitive batches in an effort to avoid detection. Both hackers and malicious users are highly motivated to target an entire distributed corporate application environment, both to avoid detection and to gain maximum access for current or future misuse. These attack profiles differ from attacks targeted at lower OSI layers (e.g., worms), as the probes and behavior are masqueraded as legitimate traffic and requests, and are not identifiable as malicious by using traditional network-based intrusion detection or intrusion prevention methods below the application-layer  110 .  
         [0003]     Application firewalls have been developed to address hacking techniques specific to hypertext transfer protocols (“HTTP” and “HTTPS”) and other protocols which use HTTP and/or HTTPS as an application-layer traffic transport mechanism (e.g., Hypertext Markup Language (HTML), Simple Object Access Protocol (SOAP), Web Services, Extensible Markup Language (XML), Web-based Distributed Authoring and Versioning (WebDAV), Lightweight Directory Access Protocol (LDAP), Active Directory, etc.). Application firewalls intercept and examine traffic content, coded instructions and protocols for potential malicious behavior and signatures, log event activity, alert IT Operations and optionally block or alter malicious traffic before it can reach downstream Web, application and database servers. Non-malicious traffic is forwarded without being blocked.  
         [0004]     Current application firewalls, whether they are implemented as separate reverse-proxy server machines, co-located with the application on the same host machine, or co-located with network firewall machines, generally operate in real-time, intrusively in-line with the applications they protect. This introduces latency while the application firewall examines the traffic, logs the activity, alerts IT Operations and/or network firewalls to suspected attacks and passes traffic on to the application. Additional latency is introduced when HTTPS traffic is examined. For instance, secure socket layer (“SSL”) protocols used in HTTPS are terminated and decrypted prior to examination; in some implementations, traffic is additionally encrypted again before passing traffic on to the Web, application, and/or database servers for final HTTPS termination. Application firewalls are not configured to take advantage of security events or behavioral anomalies detected elsewhere in the environment in the same approximate timeframe, although correlation with those events is a typical practice when auditing the forensics of events via log files, long after the events have occurred.  
         [0005]     Data security enforcement points such as column-level and file-level encryption/decryption systems have been developed to address sensitive data disclosure and theft. By setting policies for requests from legitimate users and/or applications, access rights to decrypted data are established and enforced. Some implementations also take behavioral policies into account, restricting access to data during specific time periods or limiting the number of records which can be returned in a single request or over a period of time. Requests for decrypted data outside these policy parameters are either denied entirely (no data is returned to the requesting user or application), or denied qualitatively (data is returned, but it remains encrypted and therefore unusable without cracking the encryption key).  
         [0006]     Current data security systems, whether they are implemented as separate server appliances, co-located with one or more applications on the same host machine, or co-located with data services machines such as database servers, operate in real-time, intrusively in-line with the data they protect. When sensitive, encrypted data is requested by applications rather than directly by authenticated users, the “legitimate user” is frequently no more than the application name itself. Even in cases where an actual username is passed from the application along with the data request, the data security system is “blind” to whether or not the user is a hacker or has stolen legitimate user credentials. Data security systems are not configured to take advantage of application security events detected elsewhere in the environment in the same approximate timeframe, although correlation with those events is a typical practice when auditing the forensics of events via log files, long after the events have occurred.  
         [0007]      FIG. 2  illustrates a perimeter security system  200  typically implemented in the prior art. This conventional perimeter security system  200  features a network firewall  210  (OSI layers  3 - 4 ), application firewalls  220  and  222  (OSI layer  7 ), and a network monitor  230  (OSI layers  3 - 4 ) for protecting two web servers  240  and  242 . A router  215  is provided to route incoming traffic to one of the application firewalls  220  and  222  depending on which web server  240  and  242  is intended as the recipient of the traffic. One or more consoles  250  can be provided to alert an administrator of possible intrusions and suspicious traffic originating from a public network  260  as identified by network firewall  210 , and/or application firewalls  220  and  222 , the implementations of which are apparent to one of ordinary skill in the art. Similar systems might implement only one web server, thereby necessitating only one corresponding application firewall and eliminating the need for the router  215 .  
         [0008]     Application firewalls and network-layer intrusion detection system (“IDS”) and intrusion protection system (“IPS”) devices can be deployed in various network topologies which include, but are not limited to, other systems and devices such as network firewalls, routers, switches, load balancers, and blade server environments, the implementations of which are apparent to one of ordinary skill in the art. Communication to OSI layer  1 - 6  devices and systems at the network layer has been established in the prior art as a way to block specific network activity; application firewalls may also participate in notifying network devices to drop or otherwise divert suspect IP address packets and traffic through such vendor-sponsored methods as Open Platform for Security (“OPSEC”) (although the reverse has not been implemented, as application firewall blocking has been considered secondary to network blocking from the perimeter). While the combination of all these elements may make the application and network environment more efficient, they do not directly address the key issues of latency, throughput and coordination of real-time and near real-time response in the application-layer security elements. Application-layer security system administrators are therefore forced to choose between high-latency intrusion prevention and high-risk manual response to intrusion detection as the methods currently available to protect applications and sensitive data from application-layer hackers.  
         [0009]      FIG. 3  illustrates a data security system  300  typically implemented in the prior art. This conventional data security system  300  features a network firewall  310  (OSI layers  3 - 4 ), data security enforcement points  370  and  372  (OSI layer  7 ), and a user directory  317  (OSI layer  7 ), protecting two data servers  344  and  346  used by applications  340  and  342 . A router  315  is provided to route incoming traffic to one of the requesting applications  340  and  342  depending on which is intended as the recipient of the traffic. Application  342  verifies individual user credentials through user directory  317  before passing on each data request; application  340  does not typically distinguish individual users, simply passing an application credential (“authenticated” or “anonymous”) with each data request. One or more consoles  350  can be provided to alert an administrator of illegal data requests and suspicious data requests (requests outside predetermined behavioral boundaries), the implementations of which are apparent to one of ordinary skill in the art. Similar systems might implement only direct administrative and/or local client-server access to a data server, thereby necessitating only one corresponding data security enforcement point and eliminating the need for the router  315 . While each application  340  and  342  may or may not have an application firewall in-line to intercept malicious application-layer (i.e., OSI Layer  7 ) traffic, there is no mechanism for coordination between the data security system and the application firewalls in the same approximate timeframe.  
         [0010]     There are deficiencies, therefore, in the related art relative to latency, throughput and coordination of real-time and near-real-time response to application-layer attacks and sensitive data misuse.  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention overcomes these and other deficiencies of the prior art by providing a Cooperative Processing and Escalation System (“CPES”) and method comprising a plurality of application firewalls, non-intrusive application-layer monitors, and/or data security enforcement points (individually and collectively “security nodes”), one or more sets of escalation rules and a Security Console for system administration and/or near real-time escalation event relays. Escalation and offload processing is implemented between application firewall nodes and application monitor nodes (not intrusively in-line with applications). Escalation processing is implemented as well between application firewall and/or monitor nodes and data security nodes. Moreover, a hierarchy of Operational Modes with default processing status is implemented at each security node. Exemplary configuration models for both loosely coupled and tightly coupled security nodes are provided. Automatic or semi-automatic escalation and de-escalation of multi-node status and activity is implemented in real-time and/or near real-time as initial hacking probes or sensitive data misuse occur; semi-automatic or manual override of escalation and/or operational mode is also accommodated by the present invention.  
         [0012]     In an embodiment of the invention, a cooperative processing and escalation method comprises the steps of: identifying a security violation at a security node, matching the security violation to one or more escalation rules of a pre-defined set of escalation rules, creating an escalation trigger associated with the matched escalation rule(s), and transmitting the escalation trigger to one or more receiving security nodes, wherein each of the receiving security nodes operates in two or more operational modes. The two or more operational modes are defined at one or more security nodes. The escalation trigger is processed at the receiving security node(s). The pre-defined set of escalation rules can be created automatically, semi-automatically, or manually. One or more of the pre-defined escalation rules specifies a duration of time in which an escalation to a different operational mode is enforced, followed by an automatic reversion to a default or other operational mode. Alternatively, one or more of the pre-defined escalation rules specifies an indefinite escalation to a different operational mode. The pre-defined set of escalation rules can be stored locally at or remotely from the security nodes. In one embodiment of the invention, the receiving security node is also the transmitting security node, which is otherwise known as self-escalation. An exemplary receiving security node is an application firewall, an application monitor, or a data security enforcement point. The receiving security node(s) can be defined as a logical or arbitrary grouping, defined automatically, semi-automatically or manually, comprising one or more application firewalls, application monitors, data security enforcement points, or a combination thereof. The step of defining two or more operational modes comprises the step of defining bypass, passive and active operational modes. The bypass, passive and active operational modes may optionally include sub-settings for logging and alerts associated with security violations and/or escalation triggers. The step of identifying a security violation comprises the step of analyzing in-bound or out-bound application traffic at the application-layer according to a security policy. The in-bound and/or out-bound application traffic can be transported via hypertext transport protocol (HTTP) or SSL-encrypted hypertext transport protocol (HTTPS). The step of identifying a security violation also comprises the step of examining data access requests and/or user data access behavioral patterns according to a security policy. The receiving security node processing includes the step of receiving an escalation trigger which supersedes a previously received escalation trigger. An operational mode may include forwarding a security violation alert to a security console, log or repository. An operational mode may include forwarding an escalation alert to a security console, log or repository.  
         [0013]     In an embodiment of the invention, the active mode includes examining in-bound or out-bound application-layer traffic to detect escalation rule violations and/or examining data access requests and/or user data access behavioral patterns to detect escalation rule violations. The active mode may further include blocking, redirecting, or correcting an in-bound or out-bound security violation. The active mode may also further include denying access, masking data, or denying data decryption for a data access request. The active mode may also include receiving escalation triggers.  
         [0014]     In an embodiment of the invention, the passive mode includes examining in-bound or out-bound application-layer traffic to detect escalation rule violations and/or data access requests and/or user data access behavioral patterns to detect escalation rule violations. The passive mode may further include receiving the escalation triggers.  
         [0015]     In an embodiment of the invention, the bypass mode includes receiving the escalation triggers.  
         [0016]     In an embodiment of the invention, the transmitting security node is an application firewall, an application monitor, or a data security enforcement point. In another embodiment of the invention, the transmitting security node is a network security device, wherein the network security device is a network firewall, network router or OSI layer  1 - 6  device. The transmission of an escalation alert can be routed peer-to-peer between the transmitting security node and the receiving security node(s). Alternatively, the transmission of an escalation alert can be routed from the transmitting security node to one or more hub-and-spoke network locations and thence forwarded to the receiving security node(s). In an embodiment of the invention, the transmitting security node is an application monitor tightly coupled with one or more the receiving application firewalls. In another embodiment of the invention, the transmitting security node is an application firewall tightly coupled with the receiving application monitor.  
         [0017]     In yet another embodiment of the invention, an application monitor for observing one or more applications comprises programming instructions for implementing a process comprising the steps of: deciphering in-bound and/or out-bound application-layer network traffic, applying application-layer security violation policies to the application-layer traffic to detect application-layer security violations, and selectively alternating between one of two operational modes based on the detected application-layer security violations, wherein the two operational modes include a passive mode and a bypass mode. The deciphering step operates by placing the network interface of the security node into promiscuous mode, enabling receipt of in-bound and/or out-bound application-layer network traffic without the application monitor being directly in-line with the application(s) observed. The in-bound and/or out-bound network traffic can be transported via hypertext transport protocol (HTTP) or SSL-encrypted hypertext transport protocol (HTTPS). The application-layer security violation policies for one or more applications utilize the same logical detection rules as one or more near-proximity, in-line application firewalls, in order to validate whether in-bound or out-bound application traffic is malicious. The application monitor in the passive mode performs loosely coupled cooperative processing with the near-proximity application firewall(s) by offloading processing of security violation detection, security violation alerts, security violation logging, escalation alerts, and/or escalation logging for the observed application(s). Alternatively, the application monitor in the passive mode performs tightly coupled cooperative processing with the near-proximity application firewall(s) by offloading processing of security violation alerts, security violation logging, and/or escalation logging for the observed application(s). The passive mode includes the step of transmitting peer-to-peer escalation triggers directly to the tightly coupled application firewall(s) in the event that the detected security violation matches one or more of a pre-defined set of escalation rules.  
         [0018]     In yet another embodiment of the invention, a cooperative processing and escalation system comprises: means for selectively configuring multiple network nodes to operate in two or more predetermined operational modes, and means for selectively activating the multiple nodes to operate in one of the two or more predetermined operational modes in near-real time. The network nodes can be one or more application-layer security nodes, one or more network-layer security nodes, or a combination thereof. The two or more predetermined operational modes include any two of a bypass mode, a passive mode, and an active mode.  
         [0019]     The foregoing, and other features and advantages of the invention, will be apparent from the following, more particular description of the embodiments of the invention, the accompanying drawings, and the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     For a more complete understanding of the present invention, the objects and advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:  
         [0021]      FIG. 1  illustrates an open systems interconnection model that defines a networking framework for implementing protocols in seven layers;  
         [0022]      FIG. 2  illustrates a perimeter security system typically implemented in the prior art;  
         [0023]      FIG. 3  illustrates a data security system typically implemented in the prior art;  
         [0024]      FIG. 4  illustrates an Operational Mode hierarchy for application firewalls, application monitors and data security enforcement points according to an embodiment of the invention;  
         [0025]      FIG. 5  illustrates a loosely coupled default Cooperative Processing and Escalation System (“CPES”) according to an embodiment of the invention;  
         [0026]      FIG. 6  illustrates a loosely coupled default configuration CPES according to another embodiment of the invention;  
         [0027]      FIG. 7  illustrates a loosely coupled default configuration CPES according to another embodiment of the invention;  
         [0028]      FIG. 8  illustrates a loosely coupled default configuration CPES according to another embodiment of the invention;  
         [0029]      FIG. 9  illustrates a tightly coupled default configuration CPES according to an embodiment of the invention;  
         [0030]      FIG. 10  illustrates a tightly coupled default configuration CPES according to another embodiment of the invention;  
         [0031]      FIG. 11  illustrates an escalation rules activation process according to an embodiment of the invention;  
         [0032]      FIG. 12  illustrates an escalation rules activation process according to another embodiment of the invention; and  
         [0033]      FIG. 13  illustrates an Escalation Alerts Relay system according to an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0034]     Further features and advantages of the invention, which is generally referred to as a Cooperative Processing and Escalation System (“CPES”), method or technique, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying  FIGS. 4-13 , wherein like reference numerals refer to like elements. The embodiments of the invention are illustrated in the context of the Internet, Web servers and database servers, and typically referred to as “perimeter application security.” However, one of ordinary skill in the art readily recognizes that the invention also has utility in the context of intranets, extranets, application servers, file servers, data warehouses, and indeed any combination of networks and applications where application-layer security is to be applied.  
       Overview  
       [0035]     According to at least one embodiment of the invention, a CPES comprises: rules for default operational modes, escalation triggers and de-escalation events (collectively, “escalation rules”); a security console for system configuration, hub-and-spoke relay of escalation triggers to and from loosely coupled affected security nodes, a display for displaying of near real-time system activity, at least one in-line application firewall security node, and at least one non-intrusive application monitor security node or in-line data security enforcement node. In addition, one or more of the application monitors may be tightly coupled to one or more of the application firewalls.  
         [0036]     According to another embodiment of the invention, a CPES comprises: rules for default operational modes, escalation triggers and de-escalation events; a security console for system configuration, a display for displaying of near real-time system activity, at least one in-line application firewall security node, and at least one non-intrusive application monitor security node or in-line data security enforcement node. Relay of escalation triggers to and from loosely coupled affected security nodes is handled in a peer-to-peer fashion rather than hub-and-spoke through the security console, with security hub controllers positioned at each distributed site to collect, pass along and synchronize escalation triggers to other distributed peer-to-peer security node groups. In addition, one or more of the application monitors may be tightly coupled to one or more of the application firewalls.  
         [0037]     Loose coupling may be defined both in terms of proximity (i.e., nodes are not observing and reacting to behavior for the same application, and therefore are not within close logical, physical or response timeframe proximity of each other should a security violation occur at one of the nodes) and/or the absence of direct interaction between the nodes (i.e., the nodes do not directly relay application traffic or escalation triggers between each other in a peer-to-peer fashion, but use a store-and-forward message routing such as hub-and spoke).  
         [0038]     Tight coupling may be defined both in terms of proximity (i.e., nodes are observing and reacting to behavior for the same application, and therefore are within close logical, physical and response timeframe proximity of each other should a security violation occur at one of the nodes) and the presence of direct interaction between the nodes (i.e., one or more of the nodes directly relay application traffic or escalation triggers between each other peer-to-peer).  
         [0039]     While “real-time” and “near real-time” have been used extensively to describe a timeframe element in the related and prior art (even interchangeably), the terms hold a very specific meaning in relation to application-layer security in the context of the present invention. “Real-time” system reaction is taken to mean a series of events which can occur within an immediate timeframe and in such a manner and location as to effect an automatic prevention outcome directly related to the initial triggering event. “Near real-time” system reaction is taken to mean a series of events which can occur within a relatively short period of time, the timeframe being affected by proximity and configuration, and in such a manner as to effect an automatic or semi-automatic reaction outcome related to the triggering event. Real-time events increase latency, while near real-time events do not. Thus, when the triggering event is the initial probe of a hacker against a targeted application, real-time security node reaction is only possible from a fully-activated application firewall in-line with the targeted application (and any other security nodes in-line behind the triggering application firewall, such as the data security enforcement node for the same application); any and all other events triggered within the system in relation to the initial hacker probe event occur in near real-time.  
         [0040]     Since typical attacks by application-layer hackers require multiple probes of the targeted application using various techniques before entry is gained, a near real-time reaction to the initial violation has a high probability of success in limiting or eliminating damage to the targeted application, and indeed, to all applications with security nodes participating in the reaction. An “application monitor,” inspecting the same application-layer in-bound and out-bound traffic with the same security violation policies as an application firewall, except in near real-time (without being situated directly in-line with the subject application), can therefore effectively participate in a CPES. By utilizing a network sniffing architecture rather than an in-line architecture such as reverse-proxy, the application monitor can decipher HTTP/HTTPS traffic, both in-bound and out-bound, from a SPAN or TAP network connection in promiscuous mode—the closer proximity to the observed application(s) upstream in the network topology, the shorter the reaction timeframe. Furthermore, when the same application traffic and security violation policies are in effect for a non-intrusive application monitor as for one or more in-line application firewalls, the application monitor can assume processing responsibilities for security violation detection, security violation logging, violation alerts and CPES escalation alerts.  
         [0041]     The estimated probability that a hacker will cause severe damage on an initial probing attempt represents the perceived security risk the system administrator may leverage when configuring the CPES. This ability to selectively configure a CPES to make trade-offs between latency and perceived security risk is a principal feature of the present invention, as is the ability to proactively activate application-layer prevention defenses selectively across multiple security nodes in near real-time to defend against the probability that the hacker will move on to yet another application to continue the violation attempt.  
         [0042]     In order to simplify initial configuration of the system, near proximity application firewall(s) and application monitor(s) utilize the same logical detection rules and security policies to validate whether in-bound or out-bound application traffic is malicious, but this is not a requirement for successful operation of the system. Application firewalls and application monitors may include multiple security policies addressing prevention and detection for more than one application; application monitors may include multiple security policies equivalent to those deployed at one or more application firewalls.  
       CPES Escalation Rules  
       [0043]     In order to affect the goals of a CPES (in various embodiments the ability to selectively configure a CPES to make trade-offs between latency and perceived security risk and to proactively activate and de-activate application-layer prevention defenses selectively across named security nodes, logical groups of security nodes and distributed site locations, in automatic, semi-automatic or manual fashion), a cohesive set of escalation rules should be defined. Escalation rules may be created automatically (through inference, learning-mode, or other automated process known to those of ordinary skill in the art), semi-automatically (through a presentation of automated rules for acceptance or rejection by an operator) or manually (by an operator).  
         [0044]     In an embodiment of the invention, escalation rules in a CPES comprise: 
        a. Reference-able identification of each participating security node, usually by name; IP address and type (e.g., application firewall, application monitor, data security enforcement point);     b. If logical groups of participating security nodes are used, a pointer to the logical group list;     c. Default Operational Mode of each security node (Bypass, Passive or Active—see “Operational Modes” below);     d. When in Passive Mode operation, whether security violation alerts and/or logging should occur (optional);     e. When in Active Mode operation, whether security violation alerts and/or logging should occur (optional);     f. When in Passive Mode operation, whether escalation alerts and/or logging should occur (optional);     g. When in Active Mode operation, whether escalation alerts and/or logging should occur (optional);     h. Indicator of whether each security node may receive escalation triggers, send escalation triggers, or both;     i. If the security node may send escalation triggers, one or more escalation trigger events, which indicate malicious behavior and/or increased application-layer security risk (e.g. a hacking probe, unusual data access request(s) or operator-scheduled date/time parameters);     j. For each escalation trigger event: 
            i. The Operational Mode for activation at receiving security nodes;     ii. The Operational Mode for self-escalation of the triggering security node, if any;     iii. The list of security nodes or logical groups, which will receive the escalation trigger, as well as the method of notification for each (peer-to-peer for tightly coupled or time-sensitive nodes, hub-and-spoke relay for loosely coupled nodes or distributed sites);     iv. The duration of the escalation (a period of time or indefinitely until manual operator intervention);     v. The Operational Mode for activation at each receiving security node once the escalation duration has expired (default Operational Mode or other Operational Mode);     vi. A description and severity level for the escalation trigger event (optional, for logging and alerting purposes)    
            k. Indicator of whether the escalation rule is currently active, or “on”;     l. Current Operational Mode of the local security node;     m. Indicator of whether escalation is “in progress” at the local security node;     n. Escalation expiration time at the local security node (if escalated);     o. Indicator of whether escalation logging is “on” or “off” at the local security node (optional);     p. Indicator of whether escalation alerts are “on” or “off” at the local security node (optional).        
 
         [0067]     It should be appreciated that the CPES escalation rules of the present invention can be implemented and specified in numerous ways, particularly with regard to storage and representation: in one embodiment of the invention, rules are stored locally at each participating security node to minimize latency and reaction time, in whatever representation format (XML, proprietary flat file, encrypted, etc.) is best suited to the individual node; rules may be duplicated or centralized at the security console or escalation hub controller(s) to enhance policy management, persistence, auditability, efficiency, usability, etc. Similarly, communication protocols for peer-to-peer, hub-and-spoke, waterfall, store-and-forward or other indirect relay dissemination of escalation triggers, alerts, de-escalation commands, etc., can be implemented and configured in numerous ways, as such implementation alternatives are readily apparent to those skilled in the art.  
       Operational Modes  
       [0068]     In order to affect the cooperative offload processing, tight or loose coupling configuration and escalation processing aspects of the invention, the security nodes participating in the CPES must possess certain common operational modes and behavior.  FIG. 4  illustrates an Operational Mode hierarchy  400  enacted by application firewalls, application monitors and data security enforcement points according to an embodiment of the invention, and indicates the progressive hierarchy of behavior associated with each Operational Mode. Any combination or subset of the Operational Modes may be selected as part of a default security node configuration.  
         [0069]     A Bypass Mode is the lowest level of the Operational Mode hierarchy  400 . Security nodes operating in Bypass Mode perform basic operations and “listen” for escalation alerts to trigger a higher Operational Mode, but perform no detection or prevention of malicious behavior at the application-layer. As an application firewall is in-line with downstream application(s) and data, it receives and forwards both in-bound and out-bound application traffic to and from the downstream application(s). If the traffic is in HTTPS protocol, it may optionally terminate the Secure Sockets Layer (SSL) before forwarding the traffic. As an application monitor is not in-line with downstream application(s), it receives duplicate in-bound HTTP application traffic broadcast to it from an upstream device. As a data security enforcement point is in-line with downstream data, it receives and processes in-bound data requests, encrypting and decrypting according to predetermined data access security policies, returning data to the requestor. Bypass Mode operation provides the least possible latency, highest bandwidth and transaction throughput (for application firewalls), and lowest CPU consumption of any Operational Mode. In an embodiment of the invention, the Security Console and other security nodes will never receive an escalation alert from a security node operating in Bypass Mode, further reducing network traffic and operator distraction.  
         [0070]     A Passive Mode is the second level of the Operational Mode hierarchy  400 . In addition to performing all of the tasks associated with Bypass Mode, security nodes operating in Passive Mode perform malicious behavior detection tasks, examining the in-bound application traffic and/or data requests against their respective escalation security rules to detect possible violations of interest across applications, logical application-layer groups and/or distributed site locations. Each detected violation may optionally be sent to the Security Console as an alert. Security nodes operating in Passive Mode may optionally produce logs of activity (e.g. alerts, transactions, changes in Operational Mode, statistics, etc.) for later audit and forensics analysis. If escalation rules are on for the security node at the Passive Mode level, an escalation alert will be sent to the Security Console and to any other tightly-coupled (or peer-to-peer) security node when a violation is detected. Passive Mode operation provides lower latency for application firewalls than Active Mode. Latency and CPU consumption may be further reduced by turning off logging and/or escalation rules for the application firewall. Passive Mode will be the usual default in the Operational Mode hierarchy for application monitors, as latency is not an issue. Passive Mode is also the usual default for data security enforcements points participating in a CPES environment, as normal encryption/decryption occurs while both receiving and/or detecting escalation events.  
         [0071]     An Active Mode is the highest level of the Operational Mode hierarchy  400 , and is only applicable to application firewalls and data security enforcement points. In addition to performing all of the tasks associated with Bypass and Passive Modes, application firewalls operating in Active Mode perform intrusion prevention tasks according to their respective security rules. These tasks are usually characterized by the ability to block, redirect, correct or otherwise manipulate in-bound and/or out-bound application traffic deemed malicious or flawed according to security policy. The application firewall may optionally watermark in-bound traffic via a mechanism such as a hash algorithm as part of a scheme to prevent circumvention of the application firewall according to security policy. In addition to performing all of the tasks associated with Bypass and Passive Modes, data security enforcement points operating in Active Mode perform data change and disclosure prevention tasks according to their respective security rules. These tasks are usually characterized by the ability to deny access, mask, deny decryption or otherwise suspend normal data access according to security policy, for all or selective data access requests, during the period in which escalation to Active Mode is in effect. Violation alerts, logging and escalation rules may be turned on for Active Mode, even if they were off for Passive Mode. Active Mode represents the customary, highest level of latency and CPU usage.  
         [0072]     It should be appreciated that the present invention can be implemented and configured in numerous ways, particularly with regard to the number, type, grouping and combination of cooperative coupling models employed to offload processing from in-line security nodes to non-intrusive security nodes, with regard to logical groupings of loosely coupled security nodes, with regard to actions performed in Active Mode at data security enforcement point nodes, and with regard to the methods for communicating alerts and escalation rules between security nodes and operations consoles. Several exemplary embodiments of the present invention are described below.  
       Configurations  
       [0073]      FIG. 5  illustrates a loosely coupled default configuration CPES  500  according to an embodiment of the invention. Specifically, the CPES  500  comprises a network firewall  510 , a router  515 , two active application firewalls  520  (AF 1 ) and  522  (AF 2 ) loosely coupled with a passive application monitor node  530  (AM 1 ), two Web servers  540  and  542 , and a Security Console  550 . The application firewalls  520  and  522 , in Active Mode, provide intrusion prevention for HTTP application traffic to and from the Web servers  540  and  542 . The application monitor node  530 , in Passive Mode with logging, provides intrusion detection for the same Web servers  540  and  542 . A router  515  is provided to route incoming traffic to one of the application firewalls  520  and  522  depending on which web server  540  and  542  is intended as the recipient of the traffic.  
         [0074]     Escalation rules are off in the CPES  500 , whose primary benefit is the offloading of logging and violation alerts processing from the firewalls  520  and  522  to the monitor  530 , reducing CPU consumption on the firewalls  520  and  522 , and latency to the Web servers  540  and  542 . Intrusion prevention is performed with no degradation of security strength; logging and violation alerts are provided for all in-bound traffic in near real-time by the monitor  530  to the Security Console  550 .  
         [0075]      FIG. 6  illustrates a loosely coupled default configuration CPES  600  according to an embodiment of the invention. Particularly, the CPES  600  comprises a network firewall  610 , a router  615 , one or more application firewalls  620  (AF 1 ) in Active Mode with logging providing intrusion prevention for HTTPS application traffic to and from one or more Web servers  640 , one or more application firewalls  622  (AF 2 ) in Bypass Mode directing HTTP application traffic to and from one or more Web servers  642 ; an application monitor  630  (AM 1 ) in Passive Mode with logging providing intrusion detection for the same Web servers  640  and  642 , and a Security Console  650 .  
         [0076]     Escalation rules are on at the application firewalls  620  and the application monitor  630 . The benefits include the offloading of logging and violation alerts processing from the application firewalls  622  to the application monitor  630 , reducing CPU consumption on the application firewalls  622  and lowest possible latency to its associated Web servers  642 . Intrusion prevention is performed at the application firewalls  620  with no degradation of security strength; logging and violation alerts for the application firewalls  622  are provided for all in-bound traffic in near real-time by the application monitor  630  to the Security Console  650 . In the event of a violation detected at either the application firewalls  620  or the application monitor  630 , an escalation alert is relayed through the Security Console to the application firewalls  622 , escalating the application firewalls  622  to its designated higher Operational Mode for the period of time established in the escalation rules. It should be noted that a violation at the application monitor  630  might set the application firewalls  622  to Active Mode, while a violation at the application firewalls  620  might set the application firewalls  622  only to Passive Mode, according to the level of risk deemed acceptable by the system administrator when the escalation rules were designed.  
         [0077]      FIG. 7  illustrates a loosely coupled default configuration CPES  700  according to an embodiment of the invention. Particularly, the CPES  700  comprises a network firewall  710 , a router  715 , two application firewalls  720  (AF 1 ) and  722  (AF 2 ) in Passive Mode with logging providing intrusion detection for HTTP application traffic to and from Web servers  740  and  742 , and a Security Console  750 .  
         [0078]     Escalation rules are on at the application firewalls  720  and  722 . The benefits include reduced CPU consumption and latency at the application firewalls  720  and  722 , with near real-time escalation of participating security nodes to full Active Mode status at the first detected intrusion attempt anywhere in the group. Intrusion detection only is the default at all nodes; logging and violation alerts for all in-bound traffic are provided in near real-time to the Security Console  750 . In the event of a violation detected at either the application firewall  720  or  722 , the initial detecting security node will first self-escalate to Active Mode and then relay an escalation alert through the Security Console  750  to the other loosely coupled security nodes according to the established escalation rules. Note that self-escalation may trigger in real-time or in near real-time, according to the level of risk deemed acceptable by the system administrator when the escalation rules were designed.  
         [0079]      FIG. 8  illustrates a loosely coupled default configuration CPES  800  according to an embodiment of the invention. Particularly, the CPES  800  comprises a network firewall  810 , a router  815 , an application firewall  820  (AF 1 ) in Passive Mode with logging providing intrusion detection for HTTP application traffic to and from one or more Web servers  840 , a data security enforcement point  870  (DS 1 ) in Passive Mode with logging providing encryption/decryption of sensitive data requests between Web servers  840  and database servers  844 , a data security enforcement point  872 . (DS 2 ) in Passive Mode with logging providing encryption/decryption of sensitive data requests between application servers  842  and data servers  846 , and a Security Console  850 .  
         [0080]     Escalation rules are on at the application firewalls  820  and data security enforcement points  870  and  872 . The benefits include reduced CPU consumption and latency at the application firewalls  820 , with near real-time escalation of participating security nodes  820 ,  870  and  872  to full Active Mode status at the first detected intrusion attempt or unusual data access behavior anywhere in the group. Detection of escalation rule violations only is the default at all nodes; logging and violation alerts for all in-bound traffic and data access are provided in near real-time to the Security Console  850 . In the event of a violation detected at any of the application firewall  820  or data security enforcement points  870  or  872 , the initial detecting security node first self-escalates to Active Mode and then relays an escalation alert through the Security Console  850  to the other loosely coupled security nodes according to the established escalation rules. Note that self-escalation may trigger in real-time or in near real-time, according to the level of risk deemed acceptable by the system administrator when the escalation rules were designed.  
         [0081]      FIG. 9  illustrates a tightly coupled default configuration CPES  900  according to an embodiment of the invention. Particularly, the CPES  900  comprises a network firewall  910 , a router  915 , one application firewall  920  (AF 1 ) in Bypass Mode terminating SSL for HTTPS application traffic to and from one or more Web servers  940 ; an application monitor  930  (AM 1 ) in Passive Mode with logging providing intrusion detection for the same Web servers  940  as the application firewall  920 , and a Security Console  950 . The application firewall  920  forwards a copy of in-bound HTTP application traffic to the application monitor  930 .  
         [0082]     Escalation rules are on at the application monitor  930 . The benefits include the offloading of logging and violation alerts processing from the application firewall  920  to the application monitor  930 , reducing CPU consumption on the application firewall  920  and lowest possible latency to its associated Web servers  940 , a shorter near real-time window reducing risk for Web servers downstream from the application firewall  920 , and, in the exemplary illustration, a method for providing the application monitor  930  with access to in-bound application traffic which originated as HTTPS (not possible in loosely coupled configurations). Logging and violation alerts for the application firewall  920  are provided for all in-bound traffic in near real-time by the application monitor  930  to the Security Console  950 . In the event of a violation detected at the application monitor  930 , an escalation alert is relayed directly to the application firewall  920 , escalating the application firewall  920  to its designated higher Operational Mode (Active Mode is recommended in this case) for the period of time established in the escalation rules; the application monitor  930  also relays the escalation alert to the Security Console  950  (which, in turn, will relay the escalation alert to other security nodes in the CPES  900  according to the escalation rules).  
         [0083]      FIG. 10  illustrates a tightly coupled default configuration CPES  1000  according to an embodiment of the invention. Particularly, the CPES  1000  comprises a network firewall  1010 , a router  1015 , a blade platform  1025  behind a load balancer  1018 , and a Security Console  1050 . The blade platform (“server environment”)  1025  comprises one or more application firewalls (e.g., application firewalls  1020 ,  1022 , and  1024 , which are noted as AF 1 , AF 2 , and AF 3 , respectively) in Bypass Mode directing HTTP application traffic to and from one or more corresponding Web servers (e.g., Web servers  1040 ,  1042 , and  1043 ) and an application monitor  1030  (AM 1 ) in Passive Mode with logging providing intrusion detection for the same Web servers as the Web servers  1040 ,  1042 , and  1043 .  
         [0084]     The Security Console  1050 , the network firewall  1010 , the router  1015 , and the load balancer  1018  in this exemplary embodiment are located outside the blade server environment  1025 , but it will be apparent to one of ordinary skill in the art that any or all of these elements might also be located within the blade server environment  1025 . The implementation of the load balancer  1018  is apparent to one of ordinary skill in the art.  
         [0085]     Escalation rules are on at the application monitor  1030 . The benefits of this exemplary embodiment include the offloading of logging and violation alerts processing from the application firewalls  1020 ,  1022 , and  1024  to the application monitor  1030 , reducing CPU consumption on the application firewalls  1020 ,  1022 , and  1024 , and lowest possible latency to the respective Web servers  1040 ,  1042 , and  1044 , the shortest near real-time window (coupling each security node through high-capacity cable-less services in the blade server, rather than through the usual network card interfaces) reducing risk for Web servers  1040 ,  1042 , and  1044  downstream from the application firewalls  1020 ,  1022 , and  1024 , and, in the exemplary illustration, a technique for providing the application monitor  1030  with access to in-bound application traffic which originated as HTTPS (not possible in loosely coupled configurations). Logging and violation alerts for the application firewalls  1020 ,  1022 , and  1024  are provided for all in-bound traffic in near real-time by the application monitor  1030  to the Security Console  1050 . In the event of a violation detected at the application monitor  1030 , an escalation alert is relayed directly to the application firewalls  1020 ,  1022 , and  1024 , escalating the application firewalls  1020 ,  1022 , and  1024  to their respective designated higher Operational Modes (Active Mode is recommended in this case) for the period of time established in the escalation rules; the application monitor  1030  also relays the escalation alert to the Security Console  1050  (which, in turn, will relay the escalation alert to other security nodes in the CPES  1000  according to the escalation rules).  
       Escalation Activation and De-Activation  
       [0086]      FIG. 11  illustrates an application firewall or application monitor escalation activation method  1100  according to an embodiment of the invention. The method  1100  accommodates sending escalation triggers according to escalation rules when escalation event conditions are met beginning at  1102 , and accommodates receiving an escalation trigger from another participant in the CPES beginning at  1170 .  
         [0087]     Beginning at  1102 , the security node receives HTTP/S traffic  1104  either in-bound to an application or out-bound from an application. At  1106 , if this security node is an application firewall tightly coupled to an application monitor (for purposes of cooperative processing offload, for example), the traffic at  1104  is immediately forwarded to the monitor node in  1108 . If the security node is currently in Bypass Mode  1110 , and the security node is not a monitor at  1112 , traffic at  1104  is simply forwarded to it&#39;s normal location at  1116  and method  1100  ends at  1118 , else method  110  ends at  1114 . If the security node is not currently in Bypass Mode at  1110 , the security node performs it&#39;s usual application-layer security detection function at  1120 . If an application-layer security violation has not been detected  1122 , and the security node is a monitor at  1112 , then method  1100  ends at  1114 , else traffic at  1104  is forwarded to it&#39;s normal location at  1116  and method  1100  ends at  1118 .  
         [0088]     If an application-layer security violation was detected at  1122 , the violation is checked for a match to any escalation trigger rules at  1124  (assuming escalation is turned on at this security node). If the violation did not match any escalation trigger rules at  1124  (e.g., in the case where the operator who set up the escalation rules did not specify that this type of violation posed a great enough risk to other applications, databases, or sites in the CPES to warrant an escalation trigger), then escalation processing at  1126  through  1134  is skipped and an escalation trigger is not sent out to the CPES. If the violation matched an escalation trigger rule at  1124 , the rule is checked for self-escalation at  1126 , as the ability to prevent the security violation in real-time requires an application firewall security node be in Active Mode at  1128 . If self-escalation at  1126  is not indicated by the escalation rule, as would be the case for an application monitor security node, the rules is checked to determine if this is a monitor tightly coupled to one or more application firewalls at  1130 —if this is the case, the escalation trigger is sent to the tightly coupled application firewall(s)  1132  at (the implementation of the escalation rule would be to send the escalation trigger for Active Mode, peer-to-peer, in order to reduce the near real-time response at the receiving application firewall(s) to as short a window as possible). The escalation rule for alerting the security console that the escalation trigger event has occurred is now processed at  1134 . If the security node is currently not in Passive Mode  1136 , i.e., it is in Active Mode, the security node performs it&#39;s usual application-layer security prevention function at  1140 .  
         [0089]     Operational Mode settings at the security node are checked to determine whether a violation alert should be sent  1150 , as cooperative processing may have offloaded this responsibility to a tightly or loosely coupled application monitor in the CPES—if this security node is sending it&#39;s own violation alerts, that activity is performed at  1152 . Operational Mode settings at the security node are checked to determine whether logging should occur  1160 , as cooperative processing may have offloaded this responsibility to a tightly or loosely coupled application monitor in the CPES—if this security node is performing it&#39;s own logging, that activity is performed at  1162 . Method  1100  ends at  1180 .  
         [0090]     Beginning at  1170 , the security node receives an escalation trigger from the CPES, or a manual (de-)escalation command from the security console, at  1172  (distinct from HTTP/S traffic  1104 ). The new Operational Mode is set as the current mode, and the duration of escalation is set, according to the escalation trigger or override by the security console operator  1174 —escalation duration is checked periodically at  1110  with a return to default Operational Mode when the duration has been exceeded. Operational Mode settings at the security node are checked to determine whether logging should occur  1160 , as cooperative processing may have offloaded this responsibility to a tightly or loosely coupled application monitor in the CPES—if this security node is performing it&#39;s own logging, that activity is performed  1162 . Method  1100  ends at  1180 .  
         [0091]      FIG. 12  illustrates data security enforcement point escalation activation process  1200  according to an embodiment of the invention. The method  1200  accommodates sending escalation triggers according to escalation rules when escalation event conditions are met beginning at  1202 , and accommodates receiving an escalation trigger from another participant in the CPES beginning at  1270 .  
         [0092]     Beginning at  1202 , the security node receives a data access request  1204  initiated by an application, user or other process. If the security node is currently in Bypass Mode  1210 , the data request  1204  is simply processed according to it&#39;s normal function  1216  (usually encryption or decryption of data, add/insert/update/delete of records, etc. as specified for the requesting user privileges) and method  1200  ends at  1218 . If the security node is not currently in Bypass Mode  1210 , the security node performs specific application-layer security detection functions beyond it&#39;s normal function, for example anti-fraud checks, unusual request behavior or frequency, etc., at  1220 . If an application-layer security violation has not been detected at  1222 , then the data request  1204  is forwarded to it&#39;s normal processing  1216  and method  1200  ends at  1218 . If an application-layer security violation was detected  1222 , the violation is checked for a match to any escalation trigger rules  1224 . If the violation did not match any escalation trigger rules  1224  (e.g., in the case where the operator who set up the escalation rules did not specify that this type of violation posed a great enough risk to other applications, databases, or sites in the CPES to warrant an escalation trigger), then escalation processing  1226  through  1234  is skipped and an escalation trigger is not sent out to the CPES. If the violation matched an escalation trigger rule  1224 , the rule is checked for self-escalation  1226 , as the ability to prevent the security violation in real-time requires a data security enforcement point security node be in Active Mode  1228 .  
         [0093]     The escalation rule for alerting the security console that the escalation trigger event has occurred is now processed  1234 . If the security node is currently not in Passive Mode  1236 , i.e., it is in Active Mode, the security node performs it&#39;s specific application-layer security prevention function  1240 —this may take the form of such preventative actions as denying data access, returning only encrypted data, returning only masked data, etc., for all data access requests or selectively by user name, user type, groups of users, etc., while in Active Mode. Operational Mode settings at the security node are checked to determine whether a violation alert should be sent  1250 —if this security node is sending it&#39;s own violation alerts, that activity is performed  1252 . Operational Mode settings at the security node are checked to determine whether logging should occur  1260 —if this security node is performing it&#39;s own logging, that activity is performed  1262 . Method  1200  ends at  1280 .  
         [0094]     Beginning at  1270 , the security node receives an escalation trigger from the CPES, or a manual (de-)escalation command from the security console, at  1272  (distinct from data requests  1204 ). The new Operational Mode is set as the current mode, and the duration of escalation is set, according to the escalation trigger or override by the security console operator  1274 —escalation duration is checked periodically at  1210  with a return to default Operational Mode when the duration has been exceeded. Operational Mode settings at the security node are checked to determine whether logging should occur  1260 —if this security node is performing logging, that activity is performed  1262 . Method  1200  ends at  1280 .  
         [0095]      FIG. 13  illustrates CPES  1300  escalation activation and de-activation according to an embodiment of the invention. Escalation triggers and alerts in system  1300  are relayed via both peer-to-peer and hub-and-spoke through a Security Console and application-layer security nodes, with targets either individually named or as identified by logical group names (e.g. “CPES  500 ” as shown in  500 ). Escalation is activated in real-time and near real-time across the CPES, as triggered by an initial escalation trigger event at a participating security node (from application firewall AF 1 , for example). Dotted lines in  FIG. 13  indicate potential new sources of escalation trigger events once the initial escalation trigger has raised the Operational Mode from Bypass at those security nodes. De-escalation occurs at each security node once the escalation duration has been exceeded (without further escalation triggers which supersede the last prior escalation event) or by semi-automatic or manual override via the security console  1320  or sysadmin  1320 .  
         [0096]     Although the invention has been particularly shown and described with reference to several preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.