Abstract:
Method for exchanging information between heterogeneous secured networks. Method supports synchronous communications across security domains including text chat, instant messaging, audio applications, video applications, and whiteboard collaboration. The invention intercepts incoming information traffic on either side and employs a guard for filtering information traffic between security domains according to a policy engine.

Description:
PRIORITY CLAIM UNDER 35 U.S.C. §119(e) 
     This patent application claims the priority benefit of the filing date of provisional application Ser. No. 60/860,237, having been filed in the United States Patent and Trademark Office on Nov. 1, 2006 and now incorporated by reference herein. 
    
    
     STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalty thereon. 
    
    
     BACKGROUND OF THE INVENTION 
     Technical Field of the Invention 
     This invention relates generally to the field of secure network communications. More specifically the present invention relates to securing communications across heterogeneous information networks. 
     The U.S. Intelligence Community (IC) faces an increasingly significant challenge in the timely acquisition, correlation and analysis of information. While information technology advances have resulted in the explosive growth in the volume and rate of data made available to the analyst, this seemingly limitless supply of raw intelligence threatens to overwhelm the human element of the intelligence processing system. Recent events serve to highlight the need for improved intelligence and collection management, particularly concerning Human Intelligence (HUMINT). Because of these challenges, intelligence analysis is becoming an increasingly distributed, collaborative endeavor. It is desirable to have secure information systems that support this collaboration, even if dissimilar. 
     In the intelligence production cycle, Communities of Interest (COI) are formed to collect, analyze and disseminate intelligence products. These COI teams are typically multi-disciplined, with different individuals performing different intelligence jobs and often are geographically distributed. They also often include members from different agencies, services, and possibly coalition forces. Due to the very nature of the IC, these different agencies and services each have their own private, secure networks, which create barriers to sharing information. In fact, these barriers have been cited in the media as a contributing factor as to why it was possible for the 2001 terrorist attacks to occur. Clearly, a method is needed to enable the various members of the IC to share necessary information without sacrificing security. 
     This need is further amplified when considering the United States as a global participant in the fight against terrorism. Obviously, the U.S. requires the assistance of international coalition partners in this fight, which requires intelligence information sharing across international intelligence agency boundaries. The process of authorizing data to be released to the U.S. coalition partners is slow and cumbersome. There is a paramount need for at least a semi-automated process to facilitate a quicker authorized dissemination of intelligence data from both international allied and domestic intelligence agencies. 
     To address the need of exchanging information between heterogeneous security networks, various prior art certified guarding methods have been considered. Most of the prior art, but not all of it, however, only supports email, file transfer capabilities, and/or highly-structured messaging for Common Operational Picture (COP) data. This is insufficient to satisfy the needs to which the present invention is addressed. 
     This limited functionality of the prior art is inadequate to address the needs outlined above. What is needed therefore to fulfill the perceived lack in the prior art is the capability to communicate on a real time basis, using text chat; archive and index these collaborations to facilitate research, trend analysis and information discovery; and semi-automate the process of releasing authorized information to international coalition partners. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The present invention provides cross-domain asynchronous communications capabilities of certified guards with a new capability for synchronous communication across security domains to include text chat, instant messaging, audio, video and whiteboard collaboration communications. Embodiments of the present invention provide for cross-domain text chat and instant messaging including compatibility with both one-to-one and group chat. Alternate embodiments of the present invention also include compatibility with cross-domain audio, video and whiteboard collaborations. 
     It is therefore an object of the present invention to provide a method to share information between privatized secure networks. 
     It is a further object of the present invention to provide a method to secure shared information between privatized secure networks. 
     It is still a further object of the present invention to provide a validation and authentication method to secure shared information between privatized secure networks. 
     It is yet still a further object of the present invention to provide a method for cross-domain, asynchronous network communications that supports text chat, instant messaging, audio, video and whiteboard collaboration. 
     An additional object of the present invention is to overcome a lack in the prior art wherein the security measures of implemented in privatized secure information networks would not support inter-network communications with other privatized, secure networks. 
     Briefly stated, the present invention achieves these and other objects by providing a method for exchanging information between heterogeneous secure networks. Method supports synchronous communications across security domains including text chat, instant messaging, audio applications, video applications, and whiteboard collaboration. The invention intercepts information traffic on either side and employs a guard for filtering information traffic between security domains according to a policy engine. 
     In the fundamental embodiment of the present invention, a software program method for providing secure communications across information networks, comprises digitally signing a user-generated message, forwarding said message to a conference server, determining said message type, and determining said message destination. If the message is an error message, then it is processed in the conference server. However, if the message is not an error message then the message is forwarded to a protocol proxy, a session validation request is generated and forwarded to a session manager, the session I.D. associated with that session is validated and the status of the validation step is returned. A determination is made whether the session I.D. is invalid, and if it is, then it is processed in the conference server. But if it is not invalid, an activity update is sent to a session manager, a validate message request is sent to a policy engine, the message is again validated and it is again determined whether the message is invalid. If the message is invalid, then a error is again returned. But if the message is not invalid, it is returned to the protocol proxy then forwarded to the media proxy where it is again determined whether it is invalid. If the message is invalid, then it is processed in the conference server. For a valid message, it is logged and sent to a far-side collaborative gateway. Schema and digital signatures are validated. Unauthorized or “dirty” words are checked for, digital signatures are removed from the message and resigned with the guard&#39;s private key. The message is forwarded to the far-side media proxy where it is logged, sent to the protocol proxy, then forwarded to the conference server. Message type and destination are determined whereupon it is forwarded to the user. 
     Still according to the fundamental embodiment of the present invention, a software program method for providing secure communications across information networks, validating a message further comprises determining whether the chatroom is a far-side room, and if it is, then determining whether a sender is allowed to communicate with an intended recipient. If the sender is allowed, then determining whether the chatroom is a near-side room. If the chatroom is a near-side room, then determining whether the sender is a member of that chatroom, and if he is, then determining whether the classification marking of said message is allowed. If the classification marking is allowed, then determining whether said digital signature is valid, and if it is valid, then returning the message to the protocol proxy. For messages that are not valid, rejecting them as non-authorized and generating an error message. 
     The above and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts the high-level architecture of the present invention. 
         FIG. 2  depicts a sequence diagram of the present invention. 
         FIG. 3  depicts the process flow performed within the present invention. 
         FIG. 4  depicts the process flow performed within the present invention. 
         FIG. 5  depicts the process flow performed within the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention provides a new capability to the cross-domain asynchronous communications capabilities of certified guards by providing synchronous communication across security domains including text chat, instant messaging, audio, video and whiteboard collaborations. Present embodiments of the invention provide for cross-domain text chat and instant messaging, though both one-to-one and group chat is supported. The invention is readily adaptable to alternate embodiments which provide cross-domain audio, video and whiteboard collaborations. 
     Referring to  FIG. 1 , the present invention, which can be functionally termed a “collaboration gateway” or “CG”, is depicted in a secure network. The present invention is utilized in pairs with one such present invention  90  being located on a “high-side” network  110  and one such present invention  100  being located on a “low-side”  120  network. The pair of present inventions  90 ,  100  is responsible for intercepting and forwarding text chat and instant messaging traffic between high side clients  130  low side clients  150  on each of their respective sides. The present invention  90 ,  100  runs applications that support XML protocols, chat tools, and Public Key Infrastructure (PKI). The present invention  90 ,  100  communicates with a certified guard  140  using Secure Socket Layer (SSL). The guard application provides socket-based communications and supports any real-time application, such as text chat, instant messaging, shared whiteboard, and others. 
     Referring to  FIG. 2 , a sequence diagram that illustrates the data flow and respective timelines (enumerated as “1” through “12”) within the present invention  100  as interposed between the client  130  and the Guard  140 . At first, the high side user/client  130  authenticates him/herself to the conference server by providing his/her user certificate. In the present embodiment of the invention, conference server implements the MITRE-developed Simple Instant Messaging &amp; Presence (SIMP) protocol. When the user enters a message designated for a cross-domain user (identified by the username), conference server will forward it to the high side CG server of the present invention  90 , which acts as a proxy for the recipient(s). This message is encrypted at the client&#39;s machine. 
     Still referring to  FIG. 2 , a timeline of only the high side is depicted. After verifying the high side sender&#39;s permissions to chat between the domains, present invention on the high side  90  will forward the encrypted message to the guard  140 . The data flow is then reversed, and delivered to the low side client/recipient(s)  150  (see  FIG. 1 ) on the other side of the guard  140 . An embodiment of the present invention has been prototyped and demonstrated using the Internet Engineering Task Force (IETF) standard, eXtensible Messaging and Presence Protocol (XMPP) to facilitate transport between domains. The advantage of using XMPP in the present invention is two-fold: 
     (1) allows for common set of security filters on the guard; and 
     (2) allows for interoperability between different collaboration tools 
     These objectives of the present invention are critical in meeting the requirements for the operational users in the field. First, by using a common set of security filters, less development time is necessary to support new tools, and it will be easier for the required NSA certification process. Secondly, it is highly unlikely that there will ever exist a universal collaboration tool that everybody uses. Therefore, it is necessary that the present invention provide interoperability between a plurality of tools. This is best achieved by employing a standard protocol in the present invention that each tool&#39;s message stream can be transcoded to and from. 
     Referring to  FIG. 3 , a flow diagram depicting the process steps performed by each component of the present invention, a high side user/client (see  FIG. 1 ,  130 ) digitally signs a message and sends it  160  to the conference server. At the conference server, the message is received from the chat client and the message type and the message destination are then determined  170 . Message destination is determined by instant message (IM) address. If the address is cross-domain, the message, the session I.D. and the classification marking of the message are forwarded to the invention&#39;s protocol proxy. A determination is made  180  as to whether the message received from the chat client is an error message. If it is determined that the message is an error message, such as would be the case when the process operates incorrectly, the protocol proxy sends the error message to the conference server where the message type and the message destination are determined and the error message is sent to the near user/chat client (see  FIG. 5 ,  320 ) to inform him or her that the message was not delivered. If it is determined that the message is not an error message  180 , the high side protocol proxy receives the message and sends  190  the message and a session validation request to the high side session manager. At the session manager an attempt is made to validate  200  the session I.D. of the received message. If validated, a successful status is returned  200 . If it is determined  210  that the session I.D. (SID) is not valid, the high side session manager sends the message to the conference server where the message type and the message destination are determined and the message is sent to the near user/chat client (see  FIG. 5 ,  320 ). In the process of validating, the present invention caches chatroom and user information including caching user addresses, user public keys, chatroom levels, chatroom membership, and cross-domain chatroom addresses. Otherwise, a message with a validated session I.D. is forwarded to the collaboration gateway protocol proxy where the activity time update message is generated and sent to the session manager, and a message validation request is sent to the policy engine  220 . Referring to  FIG. 4 , the present invention, a collaboration gateway, upon receipt of the message validation request from the protocol proxy, the policy engine validates  230  the message using the policy information that was loaded into the invention during system initialization. If it is determined  250  that the message is valid, the policy engine further returns the message to the protocol proxy.  230  If available, any digital fingerprint contained in the message is also checked. If it is determined  250  that the message is not valid, the policy engine returns an error  230  and the message is sent to the conference server where the message type and the message destination are determined and the message is sent to the near user/chatroom client (see  FIG. 5 ,  320 ). For a validated message, the protocol proxy will then forward  240  the validated message to the media proxy where it is logged  260  and sent to the far side collaboration gateway via the Guard API. The step of logging  260  comprises copying the message to a log file including the “to” and “from” username fields, the timestamp, and the text of the message. The guard receives the message and validates the schema and digital signature.  270  “Schema” describes the structure, content and the semantics of chat messages. The guard further checks the message for “dirty” words and removes the digital signature and resigns the message with the guard&#39;s private key.  270  “Dirty words” include a list of words that are classified and therefore may not be released from a higher security domain to a lower security domain. Lastly, the guard forwards  270  the message to the far side media proxy. The far side media proxy, once in receipt of the message, logs it and sends  280  the message to the protocol proxy. 
     Referring to  FIG. 5 , the present invention, a collaboration gateway, once the protocol proxy receives the message from the media proxy, it forwards  290  it to the conference server. The conference server receives this message from the protocol proxy as well as receiving messages from the protocol proxy when they are erroneous (see  FIG. 3 ,  180 ); when the session I.D. is invalid (see  FIG. 3 ,  210 ); and when the message is invalid (see  FIG. 4 ,  250 ). In all of these instances, the conference server will determine  300  the type of message that is received and its destination. The chat client then receives 310 the message from the conference server.